"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:5260bec4-70f4-4428-b5db-3c431e6b3e8c","http://resolver.tudelft.nl/uuid:5260bec4-70f4-4428-b5db-3c431e6b3e8c","Infragravity Wave Motions in the Scheldt Region","Grandiek, Teun (TU Delft Civil Engineering & Geosciences)","Reniers, A.J.H.M. (mentor); Tissier, M.F.S. (graduation committee); Hofland, Bas (graduation committee); Akrish, G. (graduation committee); Slomp, Robert (mentor); Delft University of Technology (degree granting institution)","2024","This study focuses on the infragravity (IG) waves at 5 measurement sites (Brouwershavense Gat 2 (BG2), Oosterschelde 4 (OS4), Cadzand, Hansweert and Bath) in the Scheldt region, examining their characteristics in these waters as well as to what extent they can be modelled using SWAN (Simulating WAves Nearshore). To facilitate this, data collected during the occurrence of four storms (Corrie, Dudley, Eunice and Franklin) that traversed the North Sea in January and February 2022 has been used.
A spectral analysis has been used to provide insight into the IG and sea-swell (SS) wave field. To this extent, the significant wave height for the IG (0.005 – 0.04 Hz) and SS (0.04 – 0.33 Hz) frequency bands have been derived, in addition to the storm averaged wave period. Measurement device BG2 documented the largest storm averaged significant wave height for both the IG and SS frequency bands (0.256 m and 3.46 m during storm Corrie, respectively). The measurement device with the smallest storm averaged significant waveheight values was Hansweert, which measured 0.024 m and 0.217 m for the IG and SS wave frequencies, also during storm Corrie. Most of the wave energy for the measurement devices in the Western Scheldt, Hansweert and Bath, can be attributed to waves with frequency values larger than the upper boundary for SS waves (T < 3 s). The fraction of the total wave energy contained within the IG and SS frequency bands ranged from 0.1 to 0.56 for these two measurement devices. Conversely, the IG and SS frequency bands contain 0.81 to 0.96 of the total wave energy for measurement device Cadzand, BG2 and OS4. The correlation between the IG and SS significant wave heights is mostly strong for the BG2, OS4 and Cadzand measurement devices (0.657 to 0.956) and generally moderate for Hansweert and Bath (0.474 to 0.87), with one outlier equivalent to 0.128). A bispectral analysis was used to offer more insight regarding the components contributing to the total IG wave field. The results at Bath proved to be erroneous for all storms except Corrie, as the derived free IG (FIG) contribution was negative. The origin remains unclear, although it appears to be related to unexplained spurious bursts in the wave elevation signal. The bispectral analysis for the remainder of the locations lead to maximum TIG wave heights ranging from 0.05 m to 0.12 m for Hansweert, 0.15 m to 0.39 m for BG2, 0.11 m to 0.35 m for OS4 and 0.21 m to 0.34 m for Cadzand for the 4 storms. The contribution of the bound IG (BIG) and FIG energy at Bath and Hansweert appears to fluctuate heavily, undergoing rapid changes on an hourly basis. For BG2, OS4 and Cadzand, the FIG energy contribution is strongly dominant as it generally amounted to > 0.75 of the TIG energy.
The capabilities of the SWAN model were evaluated by simulating FIG waves in the North Sea basin. The model relates incident SS wave energy to reflected FIG wave energy with FIG source lines based on the reflection parametrization of Ardhuin et al. (2014). The hourly SS wave inputs were provided by Copernicus Marine Service. The predictive skill was used to qualitatively assess to what extent the model is able to reproduce FIG waves in the Scheldt region. The model was unable to correctly predict the FIG waves Hansweert and Bath, where the predictive skill values for all storms ranged from 0.0003 to 0.0009 for Hansweert, and were 0 for Bath. Better predictive skill values were obtained for BG2 (0.5044 to 0.6565), OS4 (0.3327 to 0.4293) and Cadzand (0.6466 to 0.7510), but there is still room for improvement. The lacking skill values can be attributed to not enough FIG wave energy being able to penetrate the estuarine waters. Reflective lines were implemented along the coastline of the Western Scheldt in an attempt to force more FIG energy into the estuary. This only led to a minor increase for the predictive skill values (O(0.002) for Hansweert, 0 for Bath and O(0.0001) for BG2, OS4 and Cadzand) but from a spatial standpoint, it appears that there are locations in the estuary where the absolute increase was O(0.02), which is significant as there are areas in the estuary where the significant FIG wave height has doubled as a consequence of the implementation of the reflective lines.
To find opportunities for DRN, I started with an analysis of De Rijke Noordzee by interviewing employees of DRN. Based on this analysis, I found two critical needs regarding international collaboration. The need for a strategy on international collaboration between North Sea countries and a way to share knowledge on nature enhancement. Furthermore, I identified three valuable strengths of DRN: 1) connector between science, industry and government, 2) practical performer in nature enhancement projects, 3) opportunity focussed.
Thereafter, I created future contexts on Enhancing biodiversity in the North Sea by 2030 with the so called ViP method. I selected the most promising two future contexts which align with DRN’s needs and strengths: A) North Sea cooperation plays a significant role in educating people about nature topics and B) Nature education starts by engaging locally.
Based on the two analyses, I primarily focussed on the development of a strategy on North Sea collaboration (including looking for a country to start knowledge sharing with). Furthermore, on the development of ideas for DRN to share knowledge on nature enhancement projects by engaging locally.
To assess the North Sea countries, I built a decision tree based on a list of factors which influences the suitability for DRN to share knowledge with this country. The North Sea countries Germany, Denmark, UK and Belgium appeared to be suitable for collaboration from 2024 on, where Germany has the highest score. Furthermore, France and Norway might be suitable to share knowledge with in the future.
To come up with different ideas on sharing knowledge on nature enhancement by engaging locally, I organized multiple brainstorm sessions. Four ideas were selected for DRN which create the highest impact and at the same time acquire low effort to be implemented in 2024.
Consequently, I formulated a strategy on how to approach the North Sea collaboration to enhance biodiversity by 2030. This strategy is illustrated in a roadmap including selected ideas for horizon 1. The strategy is summarized as following:
Horizon 1: Share knowledge with Germany by engaging locally while: eating OWF seafood in restaurants, walking along the coast line or joining a music festival.
Horizon 2: Share and gain knowledge with and from Denmark, the UK and Belgium.
Horizon 3: Scale knowledge with France and Norway.
Besides the developed strategy, the decision tree is a structured tool for DRN to evaluate countries for collaboration in the future. Together with DRN, I discovered how the decision can be feasible, viable and desirable for them. As a result a poster was developed to inspire DRN employees. Besides, the decision tree is valuable in acquiring new funding and informing new and current stakeholders.
In addition to these outcomes for DRN, I discovered the contribution for Accenture. Together with fellow design consultants from Accenture, I explored the use of the ViP method within Accenture. I organized a brainstorm session to discuss the potential value. The session resulted in a positive response towards a VIP by a majority of my colleagues. Therefore, I designed a guide to integrate the ViP method within Accenture.
The study begins with an analysis of actors involved in the energy transition, utilizing methods like social network analysis (SNA), PESTLE analysis, and scenario analysis. The focus is on the Dutch and German electricity transmission system operator, specifically its department Grid Field Operations - Offshore (GFO-O), to understand how E-MLP can enhance comprehension of the complex and dynamic nature of the North Sea offshore energy system.
Through a mixed method approach, combining MLP, actor analysis, SNA, PESTLE analysis, and Socio-Technical Scenarios, both qualitative and quantitative data were collected and applied to gain a holistic understanding of the system. The research reveals that the North Sea offshore energy system is heavily influenced by onshore developments, supply chain considerations, grid congestion, and demand flexibility. The use of artificial intelligence enables niche innovations, while the role of small nuclear reactors is limited. Offshore focuses on energy hubs, standardization, and wind park expansion, but moving further offshore increases vulnerability. The future role of hydrogen remains uncertain, and cybersecurity and multi-use of space are crucial factors.
The study offers recommendations for GFO-O to strengthen its position, attract digital talent, invest in AI capabilities, explore demand flexibility, and investigate green hydrogen production. Policymakers should prioritize multi-use of space and engage with the military to address security threats. Incentivizing demand flexibility at the consumer level can support renewable energy production and ease the offshore system's burden.
This research contributes to the field by applying the E-MLP framework to the North Sea offshore energy system, examining actor interactions, informal institutions, and providing valuable insights for scenario analysis. However, the study acknowledges potential limitations in data availability, interview perspectives, and social network analysis. Future research can delve into specific factors such as the offshore supply chain, explore heterogeneous analysis of the oil and gas sector, and apply E-MLP to other energy transition regimes, extending the study's impact and refining the framework's application.
In conclusion, this master thesis enhances the understanding of the North Sea offshore energy system and provides policy-relevant insights for inclusive policymaking, supporting Europe's energy transition efforts to combat global warming.","Energy transition; Multi-Level Perspective; Extended Multi-Level Perspective; North Sea; Offshore; Renewable Energy","en","master thesis","","","","","","","","","","","","Engineering and Policy Analysis","",""
"uuid:cc20b151-89e2-4881-9eae-9b2b04fec7b6","http://resolver.tudelft.nl/uuid:cc20b151-89e2-4881-9eae-9b2b04fec7b6","Design and integration of an off-shore off-grid system and an on-land system for comparison on photovoltaic performance","de Gruijter Eguiluz, Álvaro (TU Delft Electrical Engineering, Mathematics and Computer Science)","Ziar, H. (mentor); Smets, A.H.M. (graduation committee); Ramirez Elizondo, L.M. (graduation committee); de Jong, Dora (graduation committee); Delft University of Technology (degree granting institution)","2023","The purpose of this thesis research was to perform a photovoltaic (PV) performance assessment and comparison between a small-scale land-based PV system and an off-shore off-grid floating PV system. Also from this research design guidelines for off-grid off-shore floating PV systems were developed. The research experiment was carried out in The Netherlands, with one system floating in the North Sea and one system standing on-land. To be able to have a fair comparison two identical 4.32 𝑘𝑊 PV arrays were built simultaneously, consisting of two parallel strings, each with six 360 𝑊𝑝 bifacial PV modules connected in series. Each of the two systems was equipped with a monitoring set up consisting of temperature sensors, pyranometers, reference cells, power meters and an inclinometer for the off-shore system. Additional measurements concerning wind, wave and water temperatures off-shore were taken from the Royal Netherlands Meteorological Institute (KNMI) weather station Hollandse Kust Zuid Alpha (HKZA), which was situated in the same region of the North Sea. The two PV experimental set-ups were compared between 15th November 2022 and 1st January 2023. On the DC side being measured, the on-land PV system recorded 96.3 𝑘𝑊ℎ while the off-shore PV system recorded 93.4 𝑘𝑊ℎ, which was subject to lower irradiance levels. The performance ratio (PR) found off-shore during the period of research was 0.92 while on-land this value was 0.934 between the two PV strings, however these values should be re-validated due to a potential malfunction of the Hall effect sensors. The PR off-shore was higher than expected from literature for a similar system being simulated. With respect to module temperatures recorded off-shore, a low thermal variation was found when compared to on-land, with the average module temperature off-shore being 11.3 𝑜𝐶 higher than on-land during this period of research. Ambient temperatures as well as irradiance on the Plane of Array (POA) were found to have a larger influence on the module temperatures for the on-land system than for the off-shore system. Module temperatures throughout the PV array off-shore were found to be the equal. Additionally, four OFPV linear regression models derived from the empirical measurements were presented and compared with existing empirical FPV models found in literature, which were found to be subject to be site and design specific. Additional environmental effects on the module temperature concerning wind, wave and water temperatures were presented, highlighting the dominant effect of the water with respect to module temperatures. The off-shore floating PV system withstood waves of up to 3.4 meters while the system maximum tilts were found to be to be 13.33 𝑜 and 17.36 𝑜 for the X and Y axis of the PV floater respectively. No permanent soiling due to bio-fouling or salt deposition was detected after one month of measurements but dynamic soiling, in the form of bio-fouling, snow and water splashing were identified, with the latter being the most predominant. The work done through this thesis lays the foundation for further research and comparisons of off-shore floating PV systems. It is recommended to perform this comparison for a period of a complete year to yield annual conclusions.","Off-shore; Solar; Floating Photovoltaics; Offshore energy; Comparison; Off-grid; Floating solar; Empirical research; OFPV; North Sea; Photovoltaic systems","en","master thesis","","","","","","","","2025-04-16","","","","Electrical Engineering | Sustainable Energy Technology","","52.319, 4.043"
"uuid:c569068a-375d-4ba7-a7a5-9940aa4c3d3a","http://resolver.tudelft.nl/uuid:c569068a-375d-4ba7-a7a5-9940aa4c3d3a","Characterizing seabed sediments using multi-spectral backscatter data in the North Sea","Bai, Q. (TU Delft Aircraft Noise and Climate Effects); Mestdagh, S.M.F. (TU Delft Aircraft Noise and Climate Effects); Snellen, M. (TU Delft Control & Operations); Amiri Simkooei, A. (TU Delft Optical and Laser Remote Sensing)","","2023","Acoustic classification using single-beam and multi-beam echosounders has been widely applied in characterizing seabed sediments. Although previous studies have shown a better discrimination of fine and coarse sediments using multi-spectral echosounder data, analysis regarding comprehensive seabed sediment properties is still needed. In this study, we used single-beam data of 24 kHz, as well as multi-beam data of 90 and 300 kHz to investigate the benefits of multi-spectral backscatter data in describing sediment properties including median grain size; weight percentages of gravel, sand, and mud; volume percentages of stones, shell fragments, and living bivalves; as well as density of acoustically hard animals (molluscs and the tube-building worm Lanice conchilega). We classified data of each frequency in an unsupervised manner, using K-means clustering for the single-beam echo time series and Bayesian classification for the multi-beam backscatter. Compared with the top-layer sediment properties, we found classification of 90 and 300 kHz consistent with variations of median grain size and L. conchilega density, whereas classification of 24 kHz can also be related to the percentages of shell fragments and stones. In addition, one acoustic class of 24 kHz might indicate a higher gravel content in the subsurface of the study area. Although quantitative relationships between backscatter and sediment properties are still difficult to achieve given a limited number of samples, using multi-spectral backscatter data is a potential approach to characterize seabed sediments from various perspectives.","acoustic classification; backscatter; multi-beam echosounder; multi-spectral; North Sea; seabed sediment; single-beam echosounder","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-12-08","","Control & Operations","Aircraft Noise and Climate Effects","","",""
"uuid:3b2b4566-fe7e-4fdb-a883-c515e8d563a1","http://resolver.tudelft.nl/uuid:3b2b4566-fe7e-4fdb-a883-c515e8d563a1","Assessing the Tidal Stream Resource for energy extraction in The Netherlands","Alday Gonzalez, M.F. (TU Delft Offshore Engineering); Lavidas, G. (TU Delft Offshore Engineering)","","2023","In order to accelerate the transition from carbon fuels to renewable energy sources, it is essential to extend our knowledge of the resources’ availability to further improve or adjust the design of extraction devices. In the present paper, a first characterization of the tidal stream resource along the coast of The Netherlands is performed using a high-resolution unstructured grid implementation of the Thetis model. Extensive validation of the sea surface elevations was done by comparing with existing networks of tide gauges in the North Sea. The simulations from this study show that the highest tidal current intensities are generated mainly at Den Helder and Oost Vlieland, reaching values >1.5 m s−1 and power density estimates that are most frequently close to 300 W m−2 and that can reach values ≥ 900 W m−2. Given the relatively reduced depths where these ‘‘hot spots’’ are found, most existing stream turbines will require further development to operate. Nevertheless, the existence of higher current intensities zones, along a commonly considered ‘‘low energy’’ coast, opens the door to include the tidal stream resource in near future plans to diversify the energy supply in The Netherlands.","Tidal stream resource; Thetis; Unstructured mesh; North Sea","en","journal article","","","","","","","","","","","Offshore Engineering","","",""
"uuid:aef10c4d-ba98-4419-b966-1f6dc1d7dead","http://resolver.tudelft.nl/uuid:aef10c4d-ba98-4419-b966-1f6dc1d7dead","Benefits of fully focused SAR altimetry to coastal wave height estimates: A case study in the North Sea","Schlembach, Florian (Technische Universität München); Ehlers, F. (TU Delft Physical and Space Geodesy); Kleinherenbrink, M. (TU Delft Mathematical Geodesy and Positioning); Passaro, Marcello (Technische Universität München); Dettmering, Denise (Technische Universität München); Seitz, Florian (Technische Universität München); Slobbe, D.C. (TU Delft Physical and Space Geodesy)","","2023","Estimating the three geophysical variables significant wave height (SWH), sea surface height, and wind speed from satellite altimetry continues to be challenging in the coastal zone because the received radar echoes exhibit significant interference from strongly reflective targets such as sandbanks, sheltered bays, ships etc. Fully focused SAR (FF-SAR) processing exhibits a theoretical along-track resolution of up to less than half a metre. This suggests that the application of FF-SAR altimetry might give potential gains over unfocused SAR (UF-SAR) altimetry to resolve and mitigate small-scale interferers in the along-track direction to improve the accuracy and precision of the geophysical estimates. The objective of this study is to assess the applicability of FF-SAR-processed Sentinel-6 Michael Freilich (S6-MF) coastal altimetry data to obtain SWH estimates as close as possible to the coast. We have developed a multi-mission FF-SAR processor and applied the coastal retracking algorithm CORALv2 to estimate SWH. We assess different FF-SAR and UF-SAR processing configurations, as well as the baseline Level-2 product from EUMETSAT, by comparison with the coastal, high-resolution SWAN-Kuststrook wave model from the Deltares RWsOS North Sea operational forecasting system. This includes the evaluation of the correlation, the median offset, and the percentage of cycles with high correlation as a function of distance to the nearest coastline. Moreover, we analyse the number of valid records and the L2 noise of the records. The case study comprises five coastal crossings of S6-MF that are located along the Dutch coast and the German coast along the East Frisian Islands in the North Sea. We observe that accurate and precise SWH records can be estimated in the nearshore zone within 1–3 km from the coast using satellite SAR altimetry. We find that the FF-SAR-processed dataset with a Level-1b posting rate of 140 Hz shows the greatest similarity with the wave model. We achieve a correlation of ∼0.8 at 80% of valid records and a gain in precision of up to 29% of FF-SAR vs UF-SAR for 1–3 km from the coast. FF-SAR shows, for all cycles, a high correlation of greater than or equal to 0.8 for 1–3 km from the coast. We estimate the decay of SWH from offshore at 30 km to up to 1 km from the coast to amount to 26.4% ± 3.1%.","Algorithm; Case study; Coastal retracking; Coastal SWH variation; Coastal zone; CORAL; FF-SAR; Fully focused SAR; North sea; Retracking; SAMOSA; SAR altimetry; Satellite altimetry; Sentinel-6 Michael Freilich; Significant wave height; SWH decay; UF-SAR; Unfocused SAR","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-06","","","Physical and Space Geodesy","","",""
"uuid:27b56abb-8d0b-44d6-aadd-938cde6e5166","http://resolver.tudelft.nl/uuid:27b56abb-8d0b-44d6-aadd-938cde6e5166","Quantifying the impacts of synoptic weather patterns on North Sea wind power production and ramp events under a changing climate","Cheneka, B.R. (TU Delft Wind Energy); Watson, S.J. (TU Delft Wind Energy); Basu, S. (TU Delft Atmospheric Remote Sensing; University at Albany - State University of New York)","","2023","Only a few studies on the overall impact of climate change on offshore wind power production and wind power ramps in the North Sea region have been published. This study focuses on the characteristics of expected wind power production and wind power ramps in the future climate aided by the classification of circulations patterns using a self-organizing map (SOM). A SOM is used to cluster high-resolution CMIP5-CORDEX sea level pressure data into 30 European area weather patterns. These patterns are used to better understand wind power production trends and any potential changes. An increased frequency of occurrence and extended persistence of high pressure systems lasting at least 24 h is projected in the future. Whereas a contrasting reducing tendency for low-pressure systems is estimated. No significant evidence is seen for a change in wind power capacity factor over the North Sea, though tentative evidence is seen for a reduction in wind power ramps. Annual energy production is seen to be dominated by a small number of weather patterns with westerly, south-westerly or north-westerly winds. Future wind power production is projected to become less from westerly winds and more from south-westerly and north-westerly flows. Ramp up events are primarily associated with strong south-westerly winds or weather patterns with a weak pressure gradient. Ramp down events have a stronger association with more north-westerly flow. In a future climate, a reduction in ramp up events associated with weak pressure gradients is projected.","Climate change; CORDEX; North Sea; Self-organizing maps; Wind ramps","en","journal article","","","","","","","","","","","Wind Energy","","",""
"uuid:1b5c9a34-64d1-4de2-9024-730cef0decd8","http://resolver.tudelft.nl/uuid:1b5c9a34-64d1-4de2-9024-730cef0decd8","Offshore green hydrogen production and transportation to shore via pipelines in the North Sea with parallel natural gas transport: A techno – economic analysis","SIACHOS, KONSTANTINOS (TU Delft Electrical Engineering, Mathematics and Computer Science)","van Wijk, A.J.M. (mentor); Lukszo, Z. (graduation committee); Blok, K. (graduation committee); Prinsen, Bob (graduation committee); Moultak, Marissa (graduation committee); Delft University of Technology (degree granting institution)","2022","The North Sea has significant potential in becoming a green energy hub, due to its remarkable offshore wind potential, and could therefore facilitate the energy transition to a net-zero energy system in Europe in the coming decades. In this transition, hydrogen is also predicted to play a key role, due to its ability to transport and store substantial amounts of energy. Previous studies have shown that for large offshore wind capacities and substantial distances from the shore, transporting the produced energy in the form of molecules (converting the electricity to hydrogen) via dedicated pipelines would be a more cost-effective option than using electricity cables and converting electricity to hydrogen. This transport could be achieved by developing new hydrogen-dedicated infrastructure or reusing existing natural gas pipelines, which is a cost-effective alternative.
This research study aims to determine the potential for repurposing existing gas infrastructure in the North Sea for hydrogen transport, taking into consideration that this infrastructure will still have to transport natural gas to the shore over the coming years. Redirecting an amount of this natural gas to other, neighboring pipelines creates the possibility for existing pipelines to be freed up for hydrogen transportation, and therefore achieve parallel transmission of green hydrogen and natural gas from the Dutch North Sea to the shore. Consequently, the purpose of this thesis project is to examine the geographical, technical, and economic feasibility of large-scale green hydrogen transportation (produced offshore with green energy from wind turbines), with parallel natural gas transport, via new and already existing gas infrastructure in the North Sea, by 2030.
The first aspect to be analyzed was the geographical configuration of such a system. For that purpose, different possible configurations for parallel transport of hydrogen and natural gas via existing North Sea infrastructure were examined. This analysis indicated that the most suitable scenario, considering the projected timeline and current circumstances, would be repurposing the NGT pipeline for 100% hydrogen transportation (produced from offshore wind search areas 7 and 3), and rerouting the natural gas to the NOGAT pipeline. Both NGT and NOGAT pipelines are parts of the North Sea offshore pipeline system, currently transporting natural gas to the Dutch shore. The next part of the study concerned the physical configuration of the hydrogen transportation system. A component analysis was done, highlighting the most suitable components across the entire system configuration, including the offshore hydrogen production by water electrolysis, its compression, and its transportation via the NGT pipeline among others.
Furthermore, a more elaborate analysis was done to determine the project’s technical feasibility, with emphasis being placed on the key aspects of hydrogen compression and transportation, evaluating its flow characteristics and compression requirements. The analysis results showed that transporting hydrogen via the NGT pipeline to the Dutch shore is technically feasible. Based on the analyzed scenario, the maximum hydrogen transport capacity was found to be 7.9 GW, and the total compression capacity 103 MW. During its transportation along the length of the pipeline (253 km), hydrogen experiences a pressure drop of 10.4 bar (65 bar to 55 bar). An economic evaluation of the system was also performed, indicating that the project is feasible from a financial standpoint as well. The LCOH transport for the proposed system, including hydrogen compression and NGT pipeline repurposing costs, was found to be 0.17 €/kg/1000km. The overall conclusion of this study is that reusing existing infrastructure in the North Sea for hydrogen transportation is a physically and technically feasible option, which can be achieved at a competitive cost.","Green hydrogen; Offshore Wind; North Sea; Hydrogen Transport; Natural Gas","en","master thesis","","","","","","","","","","","","Electrical Engineering | Sustainable Energy Technology","","53.976481, 4.087709"
"uuid:5baeb564-2a86-4a70-b10d-7d42584be888","http://resolver.tudelft.nl/uuid:5baeb564-2a86-4a70-b10d-7d42584be888","The nutrient bioextraction potential of offshore macroalgae cultivation: A study on the establishment of ecosystem services through large-scale offshore macroalgae cultivation in the North Sea","Schoenmakers, Joris (TU Delft Technology, Policy and Management)","Ward, Hauke (mentor); de Kreuk, M.K. (mentor); Delft University of Technology (degree granting institution)","2022","Due to the increasing impact of terrestrial agriculture on climate change, the attention of a myriad of industries is shifting towards the use of alternative, low-emission resources. Seaweed cultivation has presented itself as a contribution to the mitigation of the increased pressure on current resources. However, coastal and offshore marine areas are often unfit for seaweed cultivation due to increasing maritime activity. As wind farm areas are increasing, offshore seaweed aquaculture in multi-use platforms at sea (MUPS) has been proposed as one of the possibilities for smart use of ocean space. Apart from providing a multitude of benefits through the many applications of seaweed, it is also widely suggested that seaweed could offer ecosystem services during its growth by means of nutrient bioextraction of eutrophied waters. In this thesis, the critical nutrient flows of cultivation of S. latissima in MUPS at the North Sea are quantified using a dynamic mathematical nutrient model, and the impact on the marine vicinity is assessed. The assessment is performed for two scenarios: (1) a seaweed farm producing for a high-value chemicals factory, and (2) a seaweed farm producing for a fuel biorefinery. Both these scenarios are modelled over the course of one cultivation season on four offshore wind farm locations in the North Sea. Moreover, an analysis is performed on the potential role of monitoring technologies in offshore seaweed aquaculture in MUPS. The results of this study are combined to assess whether it is possible to establish ecosystem services through large-scale offshore seaweed cultivation in MUPS at the North Sea using monitoring technologies and nutrient analyses. The analysis in this study showed that offshore seaweed cultivation has a promising potential for nutrient bioextraction in the North Sea. However, nitrate depletion could occur during the last months of cultivation, when primary productivity is naturally lower. It is recommended that further research on the ecological effects of this nitrate depletion is conducted, and measures are taken to minimise the risk of detrimental effects. It is concluded that a combination of nutrient analyses and monitoring technologies could provide a more comprehensive understanding of the impact of large-scale offshore seaweed cultivation. Subsequently, this can create a solid foundation for the development of ecosystem services and the further development of the offshore seaweed sector in the near future.","Seaweed; Macroalgae; Nutrients; Impact Assessment; Monitoring technologies; Offshore; Multi-Use platforms; North Sea","en","master thesis","","","","","","","","","","","","Industrial Ecology","",""
"uuid:cad518bb-cae1-466f-86d2-fd174df8fd2e","http://resolver.tudelft.nl/uuid:cad518bb-cae1-466f-86d2-fd174df8fd2e","Using energy carrier price information to understand trade-offs between different configurations of a fully sector-coupled energy system model","Sow, Alex (TU Delft Technology, Policy and Management)","De Vries, Laurens (mentor); Okur, Ö. (graduation committee); Lombardi, F. (graduation committee); Delft University of Technology (degree granting institution)","2022","Although there is a common understanding that the use of variable renewable energy sources (VRES) is needed in our collective attempt to decarbonise society, the type of technology that we should deploy, and where is not so clear. Stakeholders from real-world projects use the outcomes from optimisation models to aid their decision-making process. One of such outcomes that decision-makers use is the price information of energy carriers in the required temporal and spatial resolution. In the current state, price information is embedded in the form of shadow prices within linear optimisation problems. As a result, price information is relatively easy to extract for conventional, power-sector focussed energy system models. However, when these energy system models are multi-carrier and sector-coupled in which energy carriers undergo several conversion stages, the extraction of price information becomes less trivial. Furthermore, even when price information is extracted in the form of shadow prices, they might not represent real-world price information. This master thesis research aims to develop a generally applicable price information generation method to extend the use of shadow-price based methods in conventional models to more complex multi-carrier fully sector-coupled models. The price information generation method is developed in Python which is tested within the Calliope modelling framework for a multi-carrier fully sector-coupled energy system. It does this by extracting the shadow prices from a linear optimisation problem of the North Sea Euro Calliope model which is adapted from the Euro-Calliope model. The shadow prices are then compared against current real-world prices for the energy carrier electricity. Results show that the shadow prices do not represent real-world prices accurately, however the use of shadow prices can be extended to understand trade-offs between different configurations of fully sector-coupled energy system models. A use case for the shadow prices has been conducted to analyse the price stability of Dutch electricity prices for different hydrogen shares within the energy system for different weather scenarios. Initial results show that the price stability of electricity in the Netherlands could be improved by increasing the share of hydrogen in the energy system. The increase of the hydrogen share within an energy system does not significantly affect the payback time of the energy system and the levelized cost of energy (LCOE) for electricity technologies. This research project shows that shadow prices could be used to understand trade-offs in different configurations of fully sector-coupled energy systems and aid the decision-making for the type and location of technologies to fulfil energy demands in the future. Recommended future research include an improvement of the North Sea Calliope model using a bottom-up approach and the analysis of other sectors within the fully sector-coupled energy system such as hydrogen and heat.","CoSEM; Optimization Modeling; Calliope; Shadow Prices; Linear programming; North Sea; Hydrogen; Sector Coupling","en","master thesis","","","","","","https://surfdrive.surf.nl/files/index.php/s/GOophfS1FWu9dtr?path=%2F North Sea Calliope model https://github.com/asow22/simple_model Simply Calliope Model","","","","","","Complex Systems Engineering and Management (CoSEM)","","51.507194, -0.127611"
"uuid:b7608abf-a7d1-41de-a434-716836fcf023","http://resolver.tudelft.nl/uuid:b7608abf-a7d1-41de-a434-716836fcf023","Extreme Waves in the North Sea: Deriving extreme wave conditions applying Hierarchical Clustering and Non-Stationary Extreme Value Modelling","Smit, Michiel (TU Delft Civil Engineering and Geosciences)","Ragno, E. (graduation committee); Lanzafame, R.C. (mentor); Antonini, A. (graduation committee); Delft University of Technology (degree granting institution)","2022","Coastal and offshore infrastructure must be designed to withstand extreme wave-induced loading conditions. Extreme Value Analysis (EVA) is often employed to infer probabilistic distributions that provide information about extreme design conditions. In traditional practices, EVA is performed under the assumption of stationarity. This means that the probability of extreme events is constant in time. However, hydraulic loading conditions are expected to exhibit temporal variability in severity and frequency as a result of climate change. Therefore, the assumption of stationarity becomes questionable. Nonstationary extreme value analysis (NEVA) for inferring extreme hydraulic loads have become more attractive in recent years. However, the applicability of NEVA models is debatable ansd differs on a case-by-case basis. Large scale oceanic bodies can be characterized by spatially and temporally varying extreme wave characteristics. Clustering analyses have proven to be successful to identify regions exhibiting similar extreme wave characteristics. Creating clusters based on similar extreme wave characteristics can potentially improve extreme value modelling because intra-cluster information can be pooled to derive more accurate extreme value models.
This research presents a practical assessment of the applicability of clustering analysis and non-stationary extreme value modeling of extreme wave statistics at cluster level in the North Sea. The primary objectives of this research are: (1) Study the temporal variability extreme significant wave height (Hm0) and extreme wind speeds (U10) in the North Sea domain, (2) Investigate how hierarchical clustering analysis (HAC) can be employed to cluster grid points that exhibit similar extreme wave characteristics, (3) How the obtained clusters and temporal variability can be employed to derive extreme value models describing extreme Hm0 statistics at cluster level and (4) assess whether NEVA models at cluster level form a practical alternative compared to conventional stationary analysis in the design and risk assessment of hydraulic infrastructure in light of climate change.
Temporal trend analysis of Hm0 in the North Sea showed that the period between 1990 and 2020 can be characterized by a decreasing trend. Between 1950 and 2020, a decrease in Hm0 intensity is observed in the Western regions and an increase is observed in the East. This is reason to believe that the variability in extreme wave climate is cyclical rather than monotonic. There is reason to believe that temporal variations of extreme U10 are responsible for the temporal variability of extreme Hm0. Initial clustering results partition the North Sea domain into 50 clusters based on characteristic values for the significant wave height (Hm0), peak period (Tp), and dominant wave directions (θ1 and θ2). After splitting clusters based on geo-location and merging clusters based on the intra-cluster statistical properties of the wave parameters, 63 clusters are obtained. The identified clusters and temporal variability are used to define NEVA models describing extreme Hm0 statistics at cluster level. Intra-cluster Hm0 observations are detrended before fitting the GEV parameters by means of Bayesian Inference. Informative priors are constructed by pooling the GEV parameter information from the intra-cluster grid points. Potential non-stationarity is accounted for by adding the Theil-Sen parameters (b and b0) to the location parameter (μ∗), making the location parameter a linear function of time. The model parameters subsequently read: Hm0 ∼ GEV (μ∗ + (b · t + b0) , σ∗, ξ∗). Using the extreme Hm0 data from the clustering centroid yields the most promising results for describing extreme Hm0 statistics at cluster level under the condition that the intra-cluster exhibits homogeneous values for b and b0.
The applied HAC analysis presented in this research is not the optimal strategy. The identified clusters exhibit heterogeneous values for b and b0 Because non-stationarity ofHm0 was not accounted for during the HAC analysis. This hinders the performance of the NEVA models at cluster level. Also, whether the derived methodology can be applied for the long-term projection of future extreme wave events in the North Sea is debatable. The non-stationary of extreme Hm0 is best described by a cyclic pattern. Without a thorough understanding of the underlying causes of the non-stationary in Hm0 and without future projections of the extreme wave climate, the applicability of NEVA for deriving extreme Hm0 design conditions in light of climate change cannot be guaranteed.","Waves; Extreme Waves; North Sea; Climate Change; Clustering; Clustering Analysis; Hierarchical clustering; Extreme Value Analysis; Non-stationarity Extreme Value Analysis; Temporal Trend Testing; hydraulic Infrastructure; Hydraulic Structures; Design and Risk Assessment; Netherlands; Flood Safety; Probabilistic design; design loads; climate adaptation","en","master thesis","","","","","","","","","","","","Civil Engineering | Hydraulic Engineering | Hydraulic Structures and Flood Risk","","56.5110, 3.5156"
"uuid:69e5aa74-9dd9-4915-8882-03b70506030a","http://resolver.tudelft.nl/uuid:69e5aa74-9dd9-4915-8882-03b70506030a","Mud dynamics in the Belgian coastal zone and siltation in the harbor of Zeebrugge","Vanlede, J.D.S.M. (TU Delft Environmental Fluid Mechanics)","Winterwerp, J.C. (promotor); Delft University of Technology (degree granting institution)","2022","Ports are important drivers for economic activity. For the Port of Zeebrugge, important sectors include cars, containers and liquefied natural gas (LNG). Due to significant siltation, frequent maintenance dredging is necessary in order to ensure the nautical accessibility. For Zeebrugge, that responsibility falls on the Flemish department of mobility and public works, at a yearly cost of about 70 millions euro. This thesis aims to contribute to the body of knowledge on the mud dynamics in the Belgian Coastal Zone, on the mechanisms behind the siltation of the harbor, and on the effects of the disposal of dredged material at sea. The cohesive sediment dynamics in the Belgian Coastal Zone (BCZ) are characterized by residual transport directed towards the northeast, and by the presence of a coastal turbidity maximum (CTM) that extends between Ostend and Zeebrugge. The resulting mud deposits are a persistent feature in the BCZ, at least since the beginning of the 20th century. Baroclinic effects, tidal asymmetry and local gradients in the residual current all play a role in trapping sediment in the CTM. In this thesis, the sediment dynamics are studied using a combination of data analysis and numerical modeling. First, a dataset is analysed that consists of 51 tripod deployments over nine years (2005-2013) at locations MOW1 and Blankenberge, kindly provided by the Royal Belgian Institute of Natural Sciences (RBINS). Tidal ensembles are derived of velocity and near-bed suspended sediment concentration (SSC). These ensembles are used to study the vertical gradient of SSC, the influence of waves, and the seasonal variation. Subsequently, a 1DV model is set up that computes the transient vertical distribution of a single fraction of SSC, and the mud content in the bed. This model is used to study the intratidal variation of the near-bed SSC observed at Blankenberge. It is shown that a two-fraction (coarse and fine) sediment model is necessary to model both the the ebb and the flood peak of SSC. Subsequently a 3D sediment transport model is set up. The settling velocity of the coarse and fine fraction are taken over from the 1DV model, as is the zero order resuspension constant. The set of measurements that is available for model calibration and validation is maximized by using both the comparable tide method and tidal ensembles. The model confirms that local hydrodynamic conditions trap sediment in the CTM, and it is used to study the role of salinity-driven baroclinic currents. A sediment balance is derived to better understand the sediment dynamics in the BCZ as an open system with some closed characteristics: even though the residual sediment transport through the Dover Strait is an important sediment supply to the BCZ, the relative importance of local erosion and deposition gives it some characteristics of a closed system, like a different clay mineralogical composition than English Channel mud.","Mud; Harbor siltation; North sea; Zeebrugge","en","doctoral thesis","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:1af34dce-0e3b-45d0-8851-b6254612185e","http://resolver.tudelft.nl/uuid:1af34dce-0e3b-45d0-8851-b6254612185e","Using Multibeam Echosounders for Multiscale and Interdisciplinary Habitat Mapping on the Dutch Continental Shelf","Koop, L. (TU Delft Aircraft Noise and Climate Effects)","Simons, D.G. (promotor); Snellen, M. (promotor); Delft University of Technology (degree granting institution)","2022","Because the seafloor is a complex ecosystem, a multidisciplinary approach must be adopted in order to produce comprehensive habitat maps. Such multidisciplinary projects have been lacking for the Dutch area of the North Sea. To address this lack, the Distribution, structure and functioning of low resilience seafloor communities and habitats of the Dutch North Sea (DISCLOSE) project, funded by the Gieskes- Strijbis Fonds, was initiated. The consortium for the project included three research institutes, as well as the North Sea Foundation. The first of the research institutes was the Delft University of Technology, tasked with the large-scale mapping of the seafloor, using acoustic systems such as the multibeam echosounder (MBES). The second research institute, the University of Groningen (UG), focused on the use of photography and videography to study the seafloor and the epifauna at a smaller, yet more detailed, spatial scale. Finally, the Royal Netherlands Institute for Sea Research (NIOZ), studied the seafloor from both the perspective of particle size and macrofauna using grab-sample data. All of these measurement methods were utilized for the same research areas, in order to maximize the possibility to established links between the sampling methods, and thereby create detailed habitat maps. The work in this thesis focuses specifically on the acoustic results generated within the DISCLOSE project. In recent years the MBES has become the standard tool for the large-scale mapping of the ocean floor. With the MBES, large swaths of the seafloor can be covered in short periods of time. The use of the two-way travel time to measure the bathymetry of the ocean has become very standardized. In addition to measuring the bathymetry, the MBES can also deliver the collocated backscatter product. The appropriate use of backscatter for the classification of seafloor properties and habitats is much less well understood than bathymetry. As such, this is an active field of research. Within Dutch waters, most research has taken place using datasets from the area of the Cleaverbank. Other areas have not been well studied, for example, the southern sandy area. Utilizing MBES backscatter-based seafloor classification in sandy areas is a major focus in this thesis. A dataset from the Brown Bank area of the North Sea was used in order to study seafloor classification over mega ripple structures. A big part of the Southern North Sea is covered in nested sand waves of different sizes. The largest of these is the tidal ridge, with some ten kilometers from crest to crest. The second largest is the sand wave, and the smallest is the mega ripple. Obviously, the main sediment type in this area is sand. Previous research suggests that a difference in grain size is to be expected between the crest of the tidal ridge to the trough. It was not known if a difference in grain size from the crest to the trough of the sand wave or the mega ripple is present, or detectable using MBES backscatter. As such, for this research a few things were very important. Firstly, it was necessary to accurately correct the backscatter for the seafloor slopes in the research area. Next, it was important to have a high spatial resolution for the final classification results. Additionally, a high geo-acoustic resolution was also needed. This final resolution is needed because it is expected that the difference in sediment properties from the trough to crest of a mega-ripple may be just slightly coarser or finer sand. From our research, it was found that it is possible to use MBES backscatter in order to classify the sediment types at the scale of mega ripples. It was found that the coarsest sediments were in the troughs, finer sediments on the stoss side slopes, and a mixture of sediments on the lee side slopes of the mega ripples...","Multibeam Echosounder; Sediment Classification; Dutch North Sea; Object-based image analysis; Backscatter; Bathymetry,; Bathymetric derivatives; Grab samples; Bayesian classification; Seafloor mapping; Benthic habitats; Marine geology; Sandbanks; Tidal ridges; Sand waves; Mega ripples; Sand ripples","en","doctoral thesis","","978-94-6384-297-6","","","","","","","","","Aircraft Noise and Climate Effects","","",""
"uuid:61b97a6d-ae37-4e2b-9309-c1196facdcf4","http://resolver.tudelft.nl/uuid:61b97a6d-ae37-4e2b-9309-c1196facdcf4","An exploratory evaluation of green hydrogen production and the social cost of offshore wind farms in the Netherlands","Bakker, Jeroen (TU Delft Technology, Policy and Management)","Lukszo, Z. (mentor); Correljé, A. (mentor); Barbour, N.M. (graduation committee); Delft University of Technology (degree granting institution)","2022","","Offshore Wind Energy; green hydrogen; North Sea; agent-based model; Social Costs","en","master thesis","","","","","","","","2026-01-12","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:9059fab5-557f-4aa0-9cb6-d31278909904","http://resolver.tudelft.nl/uuid:9059fab5-557f-4aa0-9cb6-d31278909904","The choice of feeder container ships for the North Sea and Baltic Sea region","Williams, Sam (TU Delft Mechanical, Maritime and Materials Engineering)","van Hassel, E.B.H.J. (mentor); Delft University of Technology (degree granting institution)","2022","Container ships are becoming larger and larger, but also more numerous. As a result, these large ships are pushing their smaller counterparts down the line, until these smaller ships are no longer efficient for trade routes. The focus area of this thesis is on the North Sea and Baltic Sea area, in particular the area between the West coast of Norway to the Russian part of the Gulf of Finland, with most countries in between with feeder activities between them and North European gateway hubs. This area is seeing an increase in port development. As a result, routes that container ships take are being changed. Either larger ships are coming into the region and stopping at more ports, or they are utilised as feeder ships in the region. This thesis aims to investigate the cascading effect of container ships, regarding the choice of feeder ships between German North Sea ports and feeder destinations in Scandinavian countries and countries on the Baltic Sea. To achieve this, an optimisation model is created that calculates differing total costs for container ships with capacities ranging between 200 and 5000 Twenty-foot Equivalent Units (TEU) in the region. This is done by assigning ships to container flows from German North Sea ports to feeder ports in the region, and allowing the model to choose which arcs are used to fulfil the container inflow of the destination ports. To analyse the impact of each ship type regarding the total cost of their routes taken, ship types are tested separately. Experiments have been run for increasing bunker costs based on existing data, for increasing amounts of container inflows, and decreasing the number of ports based on an increase of minimum container inflow.
The results of the experiments varying bunker costs show the total cost to fulfil all container inflows for each feeder ship type is highly dependent on its utilisation of the Kiel Canal. The Kiel Canal restricts the choice of ships with capacities larger than 1250 TEU. The extra time spent for sailing around the Northern tip of Denmark has a negative effect on the largest ships chosen for this thesis. For an increasing bunker cost, a 1500 TEU capacity ship is hindered more negatively than a 5000 TEU ship due to the Kiel Canal. For variations in volume of container flows, the same impact of the Kiel Canal is also seen. However, total costs start to favour the largest ships chosen, with the largest capacity ship (5000 TEU) having the lowest total costs calculated for a 300\% of the original chosen container flows. For decreasing the number of ports from the set based on their container inflow, the largest capacity ships have the lowest total costs from a minimum container inflow of around 400 TEU per week. From this, with current flows and within the near future, it is estimated that the current fleet of around 1000 - 1250 TEU capacity container ships will maintain their position within the North Sea and Baltic Sea region. However, for routes with a substantial container flow volume, larger capacity ships are estimated to be more cost competitive than their smaller counterparts.
This conclusion is based on experiments with only one ship size available for all container flows, with the assumption that all chosen ships are not restricted by berth sizes in ports. Furthermore, all flows originate from German North Sea ports. Recommendations for future research should take all chosen ship types into consideration for arc-flow pairing, and have more origins for container flows. If all ship types are taken into consideration, size restrictions of ports and transshipment between ship types should also be implemented. Origins included should include other major hubs in the region, as well as from outside the region, as an incoming flow. This would allow for an investigation into large container ships sailing between the current chosen origin hub and large ports, and the consequence on the region as a whole.
A realistic 3D hydrodynamic model was used to assess the recirculation during a validated spring-neap cycle. Our analysis shows that the recirculation has a maximum diameter of roughly 15 km during neap tide and 5 km during spring tide. The recirculation occurs in the buoyant top layer of the water column and grows offshore from its onset north of the Maasmond around HW+3 until it is overtaken by ebb tidal velocities around HW+5. This study shows that the onshore advection of negative (clockwise) vorticity water results in most water flowing back to the river mouth into an expanding clockwise recirculation, the vorticity and strength of which are strongly influenced by buoyant river outflow.
Our analysis shows that the headland is not a prerequisite for its onset. Nevertheless, two mechanisms are identified of how the headland influences the recirculation. First, during spring tide, the headland is found to ‘shelter’ the recirculation from strong ambient currents in the midfield which would otherwise hamper the recirculation. Secondly, the geometry of the river mouth influences the vorticity input in the North Sea associated with the buoyant river outflow.
To further investigate what processes influenced by the river outflow could contribute to the recirculation, a scale analysis and particle tracking study were deployed. Although, the study is not yet conclusive on what drives the onshore advection of the spinning water that flows into the recirculation, several potential processes have been identified.
For future studies that want to model the spreading of freshwater, pollutants or suspended sediment near the river mouth of the Rhine-Meuse system, this study underlines the importance of using a three-dimensional numerical model that accounts for density differences and the influence of the studied recirculation. The latter is especially important when the boundaries of the numerical domain are located close to the river mouth, due to which the influence of the recirculation is not resolved unless explicitly accounted for in the boundary conditions. This study therefore contributes to the improvement of future modelling studies of the Rhine ROFI and to our understanding of the processes that govern the hydrodynamics along the Dutch coast.
Various offshore infrastructural projects, like offshore wind farms, thus require long term (30-50 years) predictions of the seabed dynamics. Currently data-driven methods are used to determine the range of expected bed levels. However, the uncertainty in these predictions is significant, with sand waves being the largest source of uncertainty. Furthermore, no real understanding of the systems at hand forms the base of these predictions. Not many attempts have been made to accurately model sand wave dynamics in real-life situations using a process based model. Since sand waves often have steep slopes in migration direction, a need for small numerical grid sizes arises. On the other hand oceanic hydrodynamics are affected by large scale bed forms. To include (the influence of) these bed forms, large model domains are required. This makes numerical modelling of sand wave fields rather difficult due to the balance between grid sizes and computation time. The newly developed Delft3D Flexible Mesh (FM) model may be able to overcome some of these problems.
Through the use of unstructured grids, the desired level of detail can be reached in certain sand wave areas. In combination with the possibility to run simulations in parallel, on multiple cores, computation times can be reduced significantly. However, the Delft3D FM model has not yet been used for the prediction of sand wave dynamics. The aim of this research is to find the opportunities and challenges of the Delft3D FM model for quantitative modelling of sand wave dynamics in the North Sea.
Through two case studies various opportunities and challenges for predicting sand wave dynamics using Delft3D FM are discovered. The Delft3D FM model showed a significant reduction of computation times for a 2DV case using a single core compared to Delft3D-4. For parallel simulations, using multiple cores, an approximately linear further reduction of computation time is observed in a 2DV setting. Furthermore, the possibility of unstructured grids presents a solution for the small grid sizes needed in sand wave areas. Other computational
gains are realized through a morphological scale factor (which is also
ncorporated in Delft3D-4), optimized time-step management and a new type of boundary conditions. This new boundary condition imposes both water level and flow velocity over depth in both horizontal directions. In this way the local flow conditions are accurately represented and the influence of bed forms outside the model domain can easily be incorporated. This potentially eliminates the need for buffer zones.
Challenges for the application of Delft3D FM on sand wave cases are found in amongst others the availability of data. When less data on local hydrodynamics is available the accurate representation of processes driving sand wave dynamics becomes more difficult. Furthermore the inclusion of sub-grid processes, like the growth and migration of megaripples, could be problematic. In the model case studies no calibration was carried out. This calibration could potentially increase the effort needed to apply Delft3D FM to real life sand wave cases.
Furthermore, the Delft3D FM model is still in development and significant differences between the results of different versions of Delft3D FM were observed. Care should be taken when applying a new version of Delft3D
FM. The model is however being developed in collaboration with users which ensures quick feedback and thus stimulates improvement of the results between versions.
Recommended research includes extended exploration of the 3D effects influencing sand wave dynamics. Furthermore, improvement of morphological results and optimization of the model set-up will increase the applicability
of Delft3D FM in an engineering setting. A model run forced by two Riemann boundaries showed improved morphological results, although the hydrodynamics were not well represented. These results might indicate
where differences with reality originate. Examples of such differences are overestimation of peak velocities, exclusion of wind-driven currents and exclusion of processes like suspended sediment transport, free surface waves
and grain size sorting. Further exploration of these factors could enhance the predictive capacities of Delft3D FM. Applying the model at other locations in the North Sea will help determine the overall applicability of the model.
Through this extended research the full potential of the Delft3D FM model can be discovered and prepared for future engineering applications. Insights gained into the processes influencing sand waves dynamics, through the use of Delft3D FM, could pave the way for more nature based solutions, thus reducing the need for dredging. In this way Delft3D FM could contribute to reducing risks, costs and environmental impact of offshore construction projects in sand wave areas.","Sand waves; wind farm; morphology; North Sea; Delft3D; Flexible Mesh; unstructured grid; 3D model","en","master thesis","","","","","","","","","","","","Civil Engineering | Hydraulic Engineering","",""
"uuid:782f48be-3271-4171-8a43-5c08fc0dd81b","http://resolver.tudelft.nl/uuid:782f48be-3271-4171-8a43-5c08fc0dd81b","Rogue waves in the Dutch North Sea: An experimental study into the occurrence of extreme waves due to abrupt depth transitions at future offshore wind farm locations along the Dutch coast","Doeleman, Madelief (TU Delft Civil Engineering and Geosciences)","Reniers, A.J.H.M. (mentor); van den Bremer, T.S. (graduation committee); Hofland, B. (graduation committee); Westra, M. (graduation committee); Groeneweg, J. (graduation committee); Delft University of Technology (degree granting institution)","2021","Large morphological features, so-called sand ridges, with an average height and length in the order of 10 meters and 3 kilometers respectively are located at future offshore wind farm locations in the Dutch North Sea. Recent literature, considering relatively deep water conditions (kh 1, with k the wave number and h the water depth), has shown that a wave field propagating over a shallowing depth transition shows an increase in kurtosis. Kurtosis is a measure for the vertical deviation from the commonly applied linear ocean wave model, and therefore describes a higher probability of occurrence of ""rogue"" waves. These ""rogue"" waves are known to the general public from sailors' tales and thrilling videos. Scientifically, rogue waves are described as statistically abnormal waves and are generally classified as waves that exceed twice the significant wave height. Because these waves have an abnormal height, they are associated with extreme forces. Considering the sand ridges at future offshore wind farm locations, and possible increased damages to wind turbines due to rogue waves, this thesis researches if the increased probability of occurrence of rogue waves due to the local bathymetry as observed in the relatively deep water literature also applies to relatively shallow water conditions and the Dutch North Sea. To achieve this objective, physical experiments have been performed in the Hydraulic Engineering laboratory of the Delft University of Technology. Also, an existing statistical model that describes a rogue wave mechanism due to the presence of depth transitions is evaluated. The model describes the rogue wave mechanism as the interaction between the transmitted wave field and second-order components: the free sub- and super-harmonic components generated by the depth transition. As the model assigns a prominent role to these sub- and super-harmonics, it was ensured that these components are generated correctly during the physical experiments. Following, this thesis also assesses and contributes to the second-order wave generation at the TU Delft laboratory facility.","Rogue Waves; Second-order wave generation; North Sea; Wave phenomena; Physical experiments; Depth transition; Sand ridges; Extreme waves; Monster freak waves; wind farm; Laboratory; AUKE/PC","en","master thesis","","","","","","","","","","","","Civil Engineering | Hydraulic Engineering","","52.57,3.71"
"uuid:62d9cb00-b097-4dbb-ab67-90cb5443a0af","http://resolver.tudelft.nl/uuid:62d9cb00-b097-4dbb-ab67-90cb5443a0af","The Northern European Enclosure Dam: A multidisciplinary project on the effects of the NEED","Kollaard, Freek (TU Delft Civil Engineering and Geosciences); Meijers, Carlijn (TU Delft Civil Engineering and Geosciences); van Strien, Charlotte (TU Delft Civil Engineering and Geosciences); van der Veer, Irene (TU Delft Civil Engineering and Geosciences); de Vries, Laura (TU Delft Civil Engineering and Geosciences)","Rutten, M.M. (mentor); Voorendt, M.Z. (mentor); Delft University of Technology (degree granting institution)","2021","Many low-lying densely populated areas and important economical regions in Europe are threatened by sea level rise. \cite{groeskamp2020need} suggest an international cooperation to be able to protect these areas if climate change mitigation fails: the construction of the Northern European Enclosure Dam (NEED). In this research first order calculations are used to show the effects the construction of the NEED has inside the enclosed North Sea basin. The topics covered are: monthly water level variations; hydrodynamics (tides, waves and currents); salinity; temperature and lastly sediment transport. At first these topics are treated independently, after which a first step is made with studying their dependencies. Besides the dependencies, the implications of the NEED on the environment, economy and society are explored. The implications are also shown in a case study looking into the Wadden Sea, which is Natural UNESCO World Heritage.
It is found that, with constant pumping, the water level variability stays within a range that is an order of magnitude smaller than the tidal amplitudes that prevail nowadays. The salinity of the top layer drops with an order of magnitude as well, from 35 PSU to 3.5 PSU in 50 years, while the deep, stratified part of the basin stays salt. The surface temperature only changes slightly with a drop of 0.3 $^{\circ}$C.
The hydrodynamic processes in the enclosed North Sea basin together generate a weak anti-clockwise circulation that replaces the stronger anti-clockwise circulation imposed by the tides that prevailed before the enclosure of the basin. Due to a drop in average flow velocities, the sediment transport in the basin decreases and transforms from tide-dominated to a system where tides and wind are equally important. It is found that all of the above described changes have major implications on environment, economy and society and that much more research is needed to fully understand the changing processes and their effects.","NEED; North Sea; Northern European Enclosure Dam","en","student report","","","","","","","","","","","","","",""
"uuid:499a2a82-d7f1-469c-b785-27d60468428e","http://resolver.tudelft.nl/uuid:499a2a82-d7f1-469c-b785-27d60468428e","The role of gas infrastructure for integrating offshore wind in the North Sea region: Analysing different energy visions in the North Sea region","van Dam, Floor (TU Delft Electrical Engineering, Mathematics and Computer Science)","Correljé, A. (mentor); Kamp, L.M. (mentor); Rodhouse, T.S.G.H. (mentor); Stapersma, Pier (mentor); Delft University of Technology (degree granting institution)","2021","This research explores the different envisioned roles of gas infrastructure for integrating offshore wind into the energy system of the North Sea Region (NSR). In this research, the NSR is defined as consisting of the Netherlands, Germany, Belgium, Norway, Denmark and the United Kingdom. The NSR is characterized by the increasing use of their considerable offshore wind potential, its current decommissioning developments of coal and nuclear energy, and its history in supplying, transporting and consuming natural gas.
Within the NSR, there are different visions on how to integrate and leverage the full potential of
offshore wind. This research focuses on how these coexisting visions can be made more compatible; by being able to exist or occur together without problems or conflict. Of particular interest to us due to its large economic benefit is the repurposing of gas infrastructure.
Electricity and gas infrastructure are interrelated by electrolysers producing hydrogen gas using
electricity and gas-fueled power plants producing electricity. Focusing on the integration of offshore
wind in the energy system and the envisioned role of gas infrastructure, this research initially identified several important themes in different energy visions, such as the locations envisioned for placing
electrolysers. In short, these themes entail both technologies, infrastructure choices, socioeconomic
drivers, policies and regulations.
Subsequently, this research concluded that some themes are envisioned differently by various actors. These differences lead to multiple types of (in)compatibility of the different envisioned future
energy systems in the NSR. In order to answer our main research question, the current state of compatibility in the NSR is characterized. This is done by subdividing the different identified themes into
four different groups with varying (in)compatibility levels termed ‘Group A. Celebrated themes’, ‘Group
B. Themes where actors envision the same approach’, ‘Group C. Themes with competition between
different types of approaches’ and ‘Group D. Themes where there is no coexistence possible’.
This research concludes that there are differing visions of themes in the NSR, that for a large part
are based on fixed underlying societal and geographical themes. It is therefore impossible for actors to collaboratively pursue one uniform compatible energy integration vision, with the exact same
details envisioned by every actor in the NSR. Therefore, this research recommends collaborative futuring, defined as maintaining one’s vision whilst considering other existing visions within the relating
geographical and dimensional (gas, electricity, hydrogen, offshore wind, etc.) scope. Considering
the four previously mentioned groups, when one is ‘collaborative futuring’, one accepts that not every
theme can develop into a group ‘A. Celebrated themes’, but that one must prevent themes developing into or being a group 'D. No co-existence' theme. In order to gain insight into how different
themes can be collaborated upon, this research has designed a ‘collaboration framework’ to structure
the (in)compatibility levels of different themes.
present in other locations in the well. This means that core material is correlated to the well log. This correlation is then extended over the rest of the well. Two investigation targets were chosen, the first facies is channel base facies, consisting of very coarse sandstone, the second a swamp facies. This firstly requires a detailed core log, and a short study of the well log data. The core log is interpreted in order to try to establish some form of elektrofacies. The well data is then formatted and different principal component analyses (PCA’s) are performed in order to differentiate the facies from their surroundings. For both analyses more than 90% of the variance was explained by the first two component axes, making them reliable. Both target facies require different data sets in order to distinguish them from their surroundings. The swamp facies
becomes easily visible from the third principal component axis, while the channel base sand is harder to differentiate, being recognizable from a point cloud in a principal component plot. In total 40 coals were found to be present over the researched well interval, starting underneath the Zechstein formation, from 12800 to 13800 ft. No other similar channel base coarse sands
were found over the interval apart from the one in the cored material. Overall, it seems that the basics for this method of detection and extrapolation is quite reliable and better than using the original log data, although it does need some further development and improvement.","PCA; Carboniferous; North Sea; Westphalian; Facies Extrapolation; Coals; Coarse sand; Core Logging; Method","en","bachelor thesis","","","","","","","","","","","","","","54.218575, 2.18225"
"uuid:833a3284-e37c-463f-91c9-9e705eaf94a6","http://resolver.tudelft.nl/uuid:833a3284-e37c-463f-91c9-9e705eaf94a6","Long waves in the North Sea: Distribution, generation and measurement methods","Naporowski, Remy (TU Delft Civil Engineering and Geosciences; TU Delft Environmental Fluid Mechanics)","Reniers, Ad (mentor); Tissier, Marion (graduation committee); Akrish, Gal (graduation committee); de Schipper, Matthieu (graduation committee); Delft University of Technology (degree granting institution)","2020","This report presents the results of a research concerning long waves in the North Sea. ‘Long waves’ in this research is a collective name for various types of waves that are longer than the well-known sea-swell waves, here referred to as ‘short waves’. Wave types that are referred to as long waves are infragravity waves, meteo-tsunami’s, seiches and tides. Besides their extensive length, they distinguish themselves from regular sea-swell waves by the mechanisms responsible for their generation and the scale of their impact. Whereas short waves are generated by wind, long waves are generated by short wave-group forcing, the breaking of short waves nearshore and large atmospheric pressure variations. Long waves play a crucial role in the processes of coastline erosion and the breaching of flood defenses, as well as in the formation of rip currents and seiches. These events can lead to severe damage to hydraulic structures and possibly even casualties. A better understanding of them is thus vital for coastal safety.
Rijkswaterstaat has been collecting data regarding the occurrence of long waves on the North Sea for over a decade. Their measurement campaign started in a time when digital broadcasting signals and digital storage space were not well developed yet, making sending and storing the water surface elevation time-series not feasible. The data is therefore filtered by a FIR filter, reducing the size of the data, but also reducing the information that is contained in the data. All frequencies of approximately 0,0125 퐻푧 and higher are removed by the FIR filter. As a consequence a significant part of the infragravity signal is missing and it is not possible to perform a bispectral analysis (used to determine the bound long wave contribution). Nowadays, digital broadcasting signals and digital storage space have plenty of capacity to send and store the data, making the filter unnecessary.
Analysis of the spatial- and temporal distribution of long waves in the North Sea, shows that the majority of long waves have a yearly averaged significant wave height of 2,4 - 3,3 cm and a yearly averaged mean wave period of 125 to 140 cm. Based on data from the full decade, a clear trend in the spatial distribution of long waves cannot be distinguished, offshore and nearshore locations show approximately the same long wave properties. The seasonal analysis shows that the mean significant long wave height averaged out over all locations per season varies from 2,8 cm during summer, 2,9 cm during spring, 3,3 cm during winter to 3,5 cm during fall. For the mean wave period, the mean value averaged out over all locations per season varies from 127,5 s during summer, 128,1 s during spring, 135,6 s during winter to 136,3 s during fall. Predictions of the extreme wave conditions show that the significant wave height with a return period of 10.000 years (Dutch design condition for coastal flood defenses) are around 40-60 cm, although there is quite some uncertainty in these predictions. This uncertainty is due to a relatively short measurement period, usually 30 years of data is used for extreme wave predictions, and remarkable observations in the data.
Time-series analysis of the hourly significant wave height of long waves and predicted bound long waves (Hasselmann, 1962) (Hasselmann, 1963) shows that during mild weather conditions significant wave heights of long waves are low, with minimal contributions by the bound long waves. At the onset of a storm, the significant wave height of both long waves and bound long waves rapidly increase. At the end of the storm, they decrease to the pre-storm values. This shows that the generation of long waves occurs mainly during heavy weather conditions. Hourly significant wave heights of long waves, and especially bound long waves, show a strong correlation with significant short wave heights. The relative contribution of bound long waves (퐸푏푙푤/퐸푙푤) during a storm increases up to values of 60%, which is considerably higher than contributions of bound long waves found in other studies (Herbers et al., 1994). The high ratio of the relative bound long wave contribution, in combination with very low bound long wave activity during mild conditions, shows that the generation mechanism involving wave-group forcing is a major generation mechanism of long waves in the North Sea.","long waves; wave-group forcing; north sea; infragravity waves","en","master thesis","","","","","","","","","","","","","",""
"uuid:01138fde-58b3-4f92-9415-df4ca21530d8","http://resolver.tudelft.nl/uuid:01138fde-58b3-4f92-9415-df4ca21530d8","Geology of the Upper Jurassic to Lower Cretaceous geothermal aquifers in the West Netherlands Basin - An overview","Willems, Cees J.L. (University of Glasgow); Vondrak, Andrea (TAQA Energy BV); Mijnlieff, Harmen F. (TNO); Donselaar, M.E. (TU Delft Applied Geology; Katholieke Universiteit Leuven); Van Kempen, Bart M.M. (TNO)","","2020","In the past 10 years the mature hydrocarbon province the West Netherlands Basin has hosted rapidly expanding geothermal development. Upper Jurassic to Lower Cretaceous strata from which gas and oil had been produced since the 1950s became targets for geothermal exploitation. The extensive publicly available subsurface data including seismic surveys, several cores and logs from hundreds of hydrocarbon wells, combined with understanding of the geology after decades of hydrocarbon exploitation, facilitated the offtake of geothermal exploitation. Whilst the first geothermal projects proved the suitability of the permeable Upper Jurassic to Lower Cretaceous sandstones for geothermal heat production, they also made clear that much detail of the aquifer geology is not yet fully understood. The aquifer architecture varies significantly across the basin because of the syn-tectonic sedimentation. The graben fault blocks that contain the geothermal targets experienced a different tectonic history compared to the horst and pop-up structures that host the hydrocarbon fields from which most subsurface data are derived. Accurate prediction of the continuity and thickness of aquifers is a prerequisite for efficient geothermal well deployment that aims at increasing heat recovery while avoiding the risk of early cold-water breakthrough. The potential recoverable heat and the current challenges to enhance further expansion of heat exploitation from this basin are evident. This paper presents an overview of the current understanding and uncertainties of the aquifer geology of the Upper Jurassic to Lower Cretaceous strata and discusses new sequence-stratigraphic updates of the regional sedimentary aquifer architecture.","direct-use; Hot sedimentary aquifer; low enthalpy; North Sea basin; reservoir geology","en","journal article","","","","","","","","","","","Applied Geology","","",""
"uuid:8942c58a-2037-44ba-b4f2-c3992403d9f9","http://resolver.tudelft.nl/uuid:8942c58a-2037-44ba-b4f2-c3992403d9f9","Selection index for Wave Energy Deployments (SIWED): A near-deterministic index for wave energy converters","Lavidas, G. (TU Delft Transport Engineering and Logistics)","","2020","This study introduces a novel index that accounts for the interactions of wave climate and wave energy converters, offering an unbiased approach that considers climate variability, survivability and energy production. Application of the index is done with use of a longterm wave hindcast validated database for the North Sea. A detailed overall and monthly wave resource assessment reveals that mean expected wave resource is ≈15 kW/m, with higher nearshore values in December-January ≈20-25 kW/m. Lower magnitudes are met in July with values closer to ≈ 4-6 kW/m, as a general observation higher resource magnitude is expected at upper parts of the North Sea, with diminishing levels towards the English channel, the difference in available resource is almost half. The region favours ""smaller"" capacity devices, with energy production, with capacity factors having encouraging results. The highest mean value for a capacity factor in the region is 25-32%. However, the new index indicated that the highest capacity factor value should not be the determinant parameter. In fact, other locations have less energy production per year, but with significantly less production pattern variation and lower extreme condition probabilities.","Wave energy index; Wave energy converter; North sea; Variability; Capacity factor; Extreme values","en","journal article","","","","","","","","","","","Transport Engineering and Logistics","","",""
"uuid:6fc08ae8-88c3-47e4-8add-9727fd3a6b5c","http://resolver.tudelft.nl/uuid:6fc08ae8-88c3-47e4-8add-9727fd3a6b5c","Macrotidal Beach Monitoring (Belgium) using Hypertemporal Terrestrial Lidar","Deruyter, Greta (Universiteit Gent); De Sloover, Lars (Universiteit Gent); Verbeurgt, Jeffrey (Universiteit Gent); De Wulf, Alain (Universiteit Gent); Vos, S.E. (TU Delft Coastal Engineering)","","2020","In order to protect the Belgian coast, knowledge on natural sand dynamics is essential. Monitoring sand dynamics is commonly done through sediment budget analysis, which relies on determining the volumes of sediment added or removed from the coastal system. These volumetrics require precise and accurate 3D data of the terrain on different time stamps. Earlier research states the potential of permanent long-range terrestrial laser scanning for continuous monitoring of coastal dynamics. For this paper, this methodology was implemented at an ultradissipative macrotidal North Sea beach in Mariakerke (Ostend, Belgium). A Riegl VZ-2000 LiDAR, mounted on a 42 m high building, scanned the intertidal and dry beach in a test zone of ca. 200 m wide on an hourly basis over a time period of one year. It appeared that the laser scanner could not be assumed to have a fixed zenith for each hourly scan. The scanner compensator measured a variable deviation of the Z-axis of more than 3.00 mrad. This resulted in a deviation of ca. 900 mm near the low water line. A robust calibration procedure was developed to correct the deviations of the Z-axis. In this paper, we start by presenting the first results achieved with the current methodology. Next, we analyze the results from a 10-day measurement campaign and highlight the tide-dominated beach morphology.","Continuous Terrestrial Laser Scanning; Coastal Monitoring; Beach Mapping; North Sea","en","conference paper","International Federation of Surveyors (FIG)","","","","","","","","","","Coastal Engineering","","",""
"uuid:6d552b68-9ab2-4198-9ce2-19f43dff4f56","http://resolver.tudelft.nl/uuid:6d552b68-9ab2-4198-9ce2-19f43dff4f56","Measuring Centimeter-Scale Sand Ripples Using Multibeam Echosounder Backscatter Data from the Brown Bank Area of the Dutch Continental Shelf","Koop, L. (TU Delft Aircraft Noise and Climate Effects); van der Reijden, Karin J. (Rijksuniversiteit Groningen); Mestdagh, S.M.F. (Universiteit Utrecht); Ysebaert, Tom (NIOZ Royal Netherlands Institute for Sea Research; Wageningen University & Research; Universiteit Utrecht); Govers, Laura L. (Rijksuniversiteit Groningen; NIOZ Royal Netherlands Institute for Sea Research); Olff, Han (Rijksuniversiteit Groningen); Herman, P.M.J. (TU Delft Environmental Fluid Mechanics; Wageningen University & Research); Snellen, M. (TU Delft Aircraft Noise and Climate Effects; Deltares); Simons, D.G. (TU Delft Aircraft Noise and Climate Effects)","","2020","Backscatter data from multibeam echosounders are commonly used to classify seafloor sediment composition. Previously, it was found that the survey azimuth affects backscatter when small organized seafloor structures, such as sand ripples, are present. These sand ripples are too small to be detected in the multibeam bathymetry. Here, we show that such azimuth effects are time dependent and are useful to examine the orientation of sand ripples in relation to the flow direction of the tide. To this end, multibeam echosounder data at four different frequencies were gathered from the area of the Brown Bank in the North Sea. The acoustic results were compared to video and tide-flow data for validation. The sand ripples affected the backscatter at all frequencies, but for the lowest frequencies the effect was spread over more beam angles. Using the acoustic data made it possible to deduce the orientations of the sand ripples over areas of multiple square kilometers. We found that the top centimeter(s) of the seafloor undergoes a complete transformation every six hours, as the orientation of the sand ripples changes with the changing tide. Our methodology allows for morphology change detection at larger scales and higher resolutions than previously achieved.","angular response curve; survey azimuth; seafloor characterization; underwater video; North Sea","en","journal article","","","","","","","","","","","Aircraft Noise and Climate Effects","","",""
"uuid:e21b73ae-e1d7-4026-a928-fb5dc1cd00d3","http://resolver.tudelft.nl/uuid:e21b73ae-e1d7-4026-a928-fb5dc1cd00d3","How human activities affect the fine sediment distribution in the Dutch Coastal Zone seabed","Hendriks, H.C.M. (TU Delft Environmental Fluid Mechanics; Deltares); van Prooijen, Bram (TU Delft Environmental Fluid Mechanics); Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering); Winterwerp, J.C. (TU Delft Environmental Fluid Mechanics)","","2020","The fine sediment distribution in the seabed is an important indicator for the ecological functioning of shallow coastal seas. In this paper, we investigate the processes and conditions that determine the fine sediment distribution in the Dutch coastal zone surficial seabed, while also assessing the response of the system to human interventions. An extensive sediment dataset, collected in the Dutch coastal zone from 2006 to 2014, is presented. These data are used to map the distribution of fines in the seabed of the DCZ at unique spatiotemporal scales. For the entire Dutch coastal zone, the distribution of fines generally agrees well with previous studies. The recent extension of the Port of Rotterdam, the Maasvlakte 2 reclamation, was found to locally change the distribution of fines. In the sand mining pit and directly south of the reclamation, fines percentages in the seabed increased by more than 10%. We developed a conceptual framework to analyse the distribution of fines and how it is affected by human interventions. Three components are distinguished within this framework: (1) sources of fines; (2) transport pathways; and (3) accumulation potential. These components are determined both qualitatively and quantitatively, based on high-resolution bathymetric and hydrodynamic model data. The distinction between the three components makes it possible to unravel the contributions of different human interventions to the changes in the fines distribution. In the case of Maasvlakte 2, the local increase of fines percentage in the seabed could thus be attributed to a temporary additional source of fines and enhanced accumulation potential. The high spatiotemporal resolution of the new sediment dataset proved crucial to enable development and testing of the framework to evaluate the impact of (large) engineering works on the spatial distribution of fines.","Data analysis; Fines; Human activities; North Sea; Seabed; Shallow coastal seas","en","journal article","","","","","","","","","","Hydraulic Engineering","Environmental Fluid Mechanics","","",""
"uuid:1567b85f-6c7b-43c5-ab72-60cd6e630d9c","http://resolver.tudelft.nl/uuid:1567b85f-6c7b-43c5-ab72-60cd6e630d9c","Benthic species distribution linked to morphological features of a barred coast","Holzhauer, H. (University of Twente; Deltares); Borsje, Bas W. (University of Twente); van Dalfsen, Jan A. (NatureBased); Wijnberg, Kathelijne M. (University of Twente); Hulscher, Suzanne J.M.H. (University of Twente); Herman, P.M.J. (TU Delft Environmental Fluid Mechanics; Deltares)","","2020","The composition of benthic species communities in the nearshore zone is closely related to the hydrodynamic and morphodynamic conditions. Sustainable management of the coastal ecosystem requires knowledge about the natural dynamics as well as human-induced changes on the ecosystem. To improve our knowledge of the benthic species distribution along a dissipative sandy shore with multiple breaker bars, an extensive dataset was collected in the nearshore zone of the barrier islands Ameland and Schiermonnikoog in the Dutch North Sea. From 2010 to 2014, every year, approximately 180 grab samples along 18 cross-shore transects were collected and analyzed for sediment characteristics and macrobenthic species composition. Mixed-effect-models and partial redundancy analysis were used to analyze the importance of morphological features (i.e., slopes, bar crests, and troughs) as an explanatory variable for the benthic species distribution. The results indicate that the morphological features in themselves explain three times more variation than the environmental parameters used. This demonstrates the importance of morphological features as a factor in explaining the distribution of benthic species communities in the nearshore. Detailed information on morphological features is easy to obtain from bathymetry maps or visual inspection. Incorporating morphological features in species distribution models will therefore help to improve sustainable management of our valuable sandy coastal systems.","Barred sandy coast; Macrobenthos; Nearshore; North sea; Species distribution","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:5719ea18-c7b1-4ab3-a72c-5d7e0747ddf2","http://resolver.tudelft.nl/uuid:5719ea18-c7b1-4ab3-a72c-5d7e0747ddf2","Exploring the Trophic Spectrum: Placing Mixoplankton Into Marine Protist Communities of the Southern North Sea","Schneider, Lisa K. (Deltares; Vrije Universiteit Brussel); Flynn, Kevin J. (Plymouth Marine Laboratory); Herman, P.M.J. (TU Delft Environmental Fluid Mechanics; Deltares); Troost, Tineke A. (Deltares); Stolte, Willem (Deltares)","","2020","While traditional microplankton community assessments focus primarily on phytoplankton and protozooplankton, the last decade has witnessed a growing recognition of photo-phago mixotrophy (performed by mixoplankton) as an important nutritional route among plankton. However, the trophic classification of plankton and subsequent analysis of the trophic composition of plankton communities is often subjected to the historical dichotomy. We circumvented this historical dichotomy by employing a 24 year-long time series on abiotic and protist data to explore the trophic composition of protist communities in the Southern North Sea. In total, we studied three different classifications. Classification A employed our current knowledge by labeling only taxa documented to be mixoplankton as such. In a first trophic proposal (classification B), documented mixoplankton and all phototrophic taxa (except for diatoms, cyanobacteria, and colonial Phaeocystis) were classified as mixoplankton. In a second trophic proposal (classification C), documented mixoplankton as well as motile, phototrophic taxa associated in a principle component analysis with documented mixoplankton were classified as mixoplankton. In all three classifications, mixoplankton occurred most in the inorganic nutrient-depleted, seasonally stratified environments. While classification A was still subjected to the traditional dichotomy and underestimated the amount of mixoplankton, our results indicate that classification B overestimated the amount of mixoplankton. Classification C combined knowledge gained from the other two classifications and resulted in a plausible trophic composition of the protist community. Using results of classification C, our study provides a list of potential unrecognized mixoplankton in the Southern North Sea. Furthermore, our study suggests that low turbidity and the maturity of an ecosystem, quantified using a newly proposed index of ecosystem maturity (ratio of organic to total nitrogen), provide an indication on the relevance of mixoplankton in marine protist communities.","index of ecosystem maturity; marine protist communities; mixoplankton; North Sea; numerical ecology; routine monitoring","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:be6a41d2-6071-47b9-926d-f22c23edadba","http://resolver.tudelft.nl/uuid:be6a41d2-6071-47b9-926d-f22c23edadba","Modelling the transport and fate of buoyant macroplastics in coastal waters","van Utenhove, Erik (TU Delft Civil Engineering and Geosciences)","Reniers, A.J.H.M. (mentor); Uijttewaal, W.S.J. (mentor); de Schipper, M.A. (mentor); Kleissen, Frank (mentor); Minns, Tony (mentor); Delft University of Technology (degree granting institution)","2019","As a result of the unabated growth in plastic usage worldwide, their abundance in the marine environment has steadily increased over the last few decades. Nowadays, plastic litter is observed across all oceans and shores. Due to their wide spread and adverse effects on ecology, economy and potentially human health, plastic pollution has been recognized as a worldwide environmental and ecological threat. For these reasons, it is important to reduce and mitigate the abundance of plastic litter in the marine environment. As marine plastic litter predominately originates from near the coast, it is critical to study the plastic behaviour in coastal waters. However, there is considerable uncertainty regarding what factors are influencing the trajectories, distribution and deposition sites of plastic litter. Along with complex physical processes and scarcity of empirical data, there is currently little knowledge and understanding on the transport and fate of plastics in coastal waters.
With the aim of obtaining more insight into plastic behaviour, the present study intends to examine the most important processes and quantify the effects of parameter uncertainty on modelling the transport and fate of buoyant macroplastic in coastal waters. The transport and fate of plastics is modelled by combining hydrodynamics with particle tracking concepts. For the simulations the Delft3D software Suite was used, where a Delft3D-FLOW model of the southern North Sea (ZUNO-DD) was coupled to Delft3d-PART. The model calculates how the position of plastic particles evolves in time from their release until the end of the simulation. In this study, model simulations are used as a numerical tool for exploring the relative influence of current uncertainties inherent in process parameters and data inputs on model results. A set of scenarios were defined by changing parameter values on at a time. By studying the changes in particle trajectories and shoreline deposition areas, a better understanding of their relative importance was obtained.
The modelling results imply that the effect of windage and release location are the most important parameters. Further, it is observed that dominating driving mechanisms may change with varying forcing conditions and object characteristics. Other factors such as small-scale processes and moment of release may impact particle trajectories and fate. However, the relative influence of these processes is less significant and therefore considered less critical. Adopting the findings of this thesis into decision making policy can support emergency response operations and monitoring strategies.
The research on plastic behaviour in the coastal environment is still in its early stage, and much has yet to be revealed. Therefore, further improve understanding of buoyant macroplastic behaviour is required. Validation of the results presented in this study is limited due to the scarcity of empirical data. Thus, further research should be directed towards collecting more field data. Further, it is recommended that effort is put into parametrizing accurately the effect of windage. Furthermore, expanding numerical simulations should be
expanded to a range of conditions and coastal environments so that trends can be compared and highlighted, but also allows for exploring new hypotheses.
In the past, people faced the challenge of passing the fearful water by improving sailing boats, discovering navigation techniques and studying its natural movements, currents and tides. This process helped us to familiarise ourselves with the initially unknown and to learn how to coexist with nature. Today, we are confronted with the increasing power of water, which we have fortified ourselves against from it by building high advanced dams, walls and floodgates. We are using physical, monstrous engineering interventions to protect ourselves from the water rather than embracing its power – like we did in the past.
The design in itself aims to tackle the current issue of water level rise in a more traditional way, to open up to nature, to understand its behaviour and draw on our experience and knowledge.
The project has been set on the Shetland Islands, to metaphorically connect the story of the project with the first settlers of the Isles first settlements of the Vikings. Historically they embraced the fear of the waters mystical power and sailed through the unknown sea. As a link to the present, the geographical location of the Shetlands’ dictates that their coastal line will be one of the first to be impacted by the rising sea. Moreover, the island is by definition a transitional territory, the link between the Norwegian Sea and the North Sea.
The relationship between the power of water and the site was further explored in the architectural proposal. It was important to develop a cohesive narrative in the design, to bridge the past and present perception of water’s power with the site. This specifically related to the introduction of using renewable water energy as the main component of the project. By analysing local issues of the Isles’ residents and researching current knowledge of using water’s power, the site issues with the advanced technologies were combined into one coherent solution. By following this, I had to consider how far I can use the aforementioned natural power to not to damage the rough beauty of the site as well as the rough beauty of the natural power of water. This led to the introduction of the three architectural elements of my design– the harbour, the tidal power plant and the experiential path which links these two - the traditional way of using water (the harbour) with the advanced one (tidal power plant). Given the poetical nature of my project, the three interventions act as one line of experience, the deconstruction and analysis of building the tension and reflection of the story around the natural power of water, was an important procedure of translating the narrative into an invented design.","North Sea; Water level; Power; transitional territories; Landscape; Tidal Power Plant; Renewable Energy; Shetland Islands; Vikings; Water Lever Rise; Coastal Engineering; nature; Human power; history","en","master thesis","","","","","","","","","","","","Architecture, Urbanism and Building Sciences | Transitional Territories","","60.346958, 1.235660"
"uuid:4fdf954a-562a-4866-98ce-03499b6db31b","http://resolver.tudelft.nl/uuid:4fdf954a-562a-4866-98ce-03499b6db31b","The Port and the Automaton: An Investigation into the automated transition of the humber estuary and its port infrastructure","da Fonseca, Ana (TU Delft Architecture and the Built Environment)","Milani, Stefano (mentor); Marzot, Nicola (graduation committee); Holst, Sjap (graduation committee); Delft University of Technology (degree granting institution)","2019","This project initiates by looking at the space as a territory (Raffestin, 2012), constructed through social interactions and networks. I believe the design project must anticipate the global social and economic shifts that are present within the territory of the North Sea and must be shaped in relation to the effects of these changes on local societal level. Mapping is used as a tool of associating, ordering and projecting the changes in the qualities (territorialities) of the space rather then a mere visualisation tool (Corner,1999). Equally important, The scripting of scenarios based on literature and statistical data allows for the depiction of the alternate realities that the societal shifts could produce. Taking Port Landscapes, Automation and the energy transition as drivers of change, the project aims at redesigning an automated infrastructure for windblade production, storage and maintanance, and with that reshaping the coastal form based on this process. The aim is in determining the relationship between automation, form and the port landscape. Taking both automated and natural processes into account when designing, the project is inspired by the writings of Martin Pawley, in his work Terminal Architecture (Pawley, 1998) he writes: “ The real barometer of the value of buildings today is not their aesthetic pedigree, but rather their usefullness as terminals in the maze of networks that sustain modern life.Authentic Architecture has been disurbanised. It survives only in the shape of building like distribution centers, factories, petrol stations, that are designed as instruments not monuments.” The design depicts the process and actions of the machine. An automated line, hatched by the elements involved in the different processes along it. An attempt of containment and exposure of the ever expanding developments in automation and production. Human actors are no longer present within the confinement of the interior space, and instead as automation is pushed further out to sea due to increasing vessel size and production capacity, the Human remains on the coastline, to bear witness to this new separation between themselves and production. The human is now the spectator of this ever ending automated line.
Key words: North Sea, Ports, Infrastructure, Automation
This project traces the myth of ‘making new land’ by investigating the four major themes from the recent publication ‘Sweet and Salt: The Water and The Dutch’: conflict, concord, profit and pleasure. These themes are adapted and used to analyse the Dutch waterscapes of the Wadden Sea and the island of Schiermonnikoog. The scenario method is then used to project the outcome of this analysis into a future where West Frisian island of Schiermonnikoog is left to nature and risks slowly disappears into the currents of the North Sea. The design intervention narrates a new myth: ‘guarding the water’ by using the typology of a fort. The scenario has four chapters and each of them narrates a different time period of the island’s future. Thus the project derives its name from the heraldic motto of Zeeland: ‘Luctor et Emergo' - ‘I struggle and Emerge’.
and ground truth for the intertidal area is 43 cm (bias 12 cm) on a 7.5 m squared grid. Sensitivity analysis of four parameters (i.e. vertical resolution, inclusion of wave induced effects on water level, length and position of analysis window, thresholds in quality check) reveals, that TWA is most sensitive to the choice of thresholds. Sensitivity analysis is utilized to tune TWA to achieve full coverage of the intertidal area (zero coverage elsewhere) with sufficient accuracy. Additionally it is found that at costs of accuracy the period for which averaged bed levels are retrieved can be shortened from 14.5 to 8.3 days. This is promising, because RDB potentially is able to observe short-term changes in the order of a few days (e.g. storm events). To demonstrate the value of the improved TWA for bathymetry surveys in intertidal areas the method is applied to a 3.2 km stretch of beach in front of Bunker Hill station, capturing the beach state variations in the course of 2017. During wind sea dominated season (winter) a ridge-runnel type of beach is present, that changes to a skewed transverse bar and rip system during swell dominated season (summer). The method is sufficiently accurate and robust for application and proves its potential to reveal new insights, e.g. indications on how the transition between two beach states evolves. In coastal science RDB could serve as a tool to improve existing theories by providing detailed information, that reveals underlying processes. In coastal engineering it fills gaps in monitoring schemes, for example to evaluate effects of nourishment strategies.","morphodynamics; X-band; intertidal; bathymetry mapping; Sylt; North Sea; Temporal Waterline Approach; remote sensing; intermediate beach; foreshore; radar","en","master thesis","","","","","","","","","","","","Civil Engineering","","54.790264776, 8.28322493"
"uuid:e9cba524-12b1-4d93-8ac4-e0bf4af10cf2","http://resolver.tudelft.nl/uuid:e9cba524-12b1-4d93-8ac4-e0bf4af10cf2","North Sea Wave Database ( NSWD ) and the need for reliable resource data: A 38 year database for metocean and wave energy assessments","Lavidas, G. (TU Delft Transport Engineering and Logistics); Polinder, H. (TU Delft Transport Engineering and Logistics)","","2019","The study presents a newly generated hindcast database of metocean conditions for the region of the North Sea by parametrising the newly introduced ST6 physics in a nearshore wave model. Exploring and assessing the intricacies in wave generation are vital to produce a reliable hindcast. The new parametrisations perform better, though they have a higher number of tuneable options. Parametrisation of the white capping coefficient within the ST6 package improved performance with significant differences 20–30 cm. The configuration which was selected to build the database shows a good correlation 95% for Hm0, has an overall minimal bias with the majority of locations being slightly over-estimated 0.5–1 cm. The calibrated model was subsequently used to produce a database for 38 years, analysing and discussing the metocean condition. In terms of wave energy resource, the North Sea has not received attention due to its perceived ``lower'' resource. However, from analysing the long-term climatic data, it is evident that the level of metocean conditions, and subsequently wave power, can prove beneficial for development. The 95th percentile indicates that the majority of the time Hm0 should be expected at 3.4–5 m, and the wave energy period Te at 5–7 s. Wave power resource exceeds 15 kW/m at locations very close to the coast, and it is uniformly reduced as we move to the Southern parts, near the English Channel, with values there being 5 kW/m, with most energetic seas originating from the North East. Results by the analysis show that in the North Sea, conditions are moderate to high, and the wave energy resource, which has been previously overlooked, is high and easily accessible due to the low distance from coasts. The study developed a regional high-fidelity model, analysed metocean parameters and properly assessed the energy content. Although, the database and its results can have multiple usages and benefit other sectors that want to operate in the harsh waters of the North Sea.","NSWD; North Sea; resource assessment; wave energy; wave modelling; wind drag","en","journal article","","","","","","","","","","","Transport Engineering and Logistics","","",""
"uuid:de29542f-2393-4a30-8b2a-ad9d69ed758d","http://resolver.tudelft.nl/uuid:de29542f-2393-4a30-8b2a-ad9d69ed758d","Anchoring the Warmoezier: a life-cycle market in a port-city","Fajardo Ibarra, Efrain (TU Delft Architecture and the Built Environment)","Milani, Stefano (mentor); Marzot, Nicola (mentor); Holst, Sjap (mentor); Delft University of Technology (degree granting institution)","2018","The relationship between industry and market, in the Netherlands of the 17th century, was based on a sustainable model. It linked small scale producers with consumers through a system of canal boats, maritime technology and agricultural innovations.
This marketproduction connection was carried out by farmers known as ‘warmoeziers’. In 21th century Netherlands, canal transportation or ‘binnenvaart’ is acquiring more importance thanks to economical and sustainable benefits.
Complimentary to the global seaports, the canal boats can reach directly the customers in the cities. This revival of ‘binnenvaart’ can allow for a new type of city market to emerge, where automatization, innovations in food production and vibrant public life goes hand in hand with a lower CO2 footprint. The aim of this ‘warmoezier market’ is to merge the state of contemporary port-cities with the expertise of the past resulting in a market building.
Over the last twenty years, the wind energy capacity has increased significantly to become the current second highest power generation form of the European Union. The downside to offshore wind energy however, are the high costs that come with its generation. Cable losses of alternating currents between the wind turbines and the shore become increasingly high, as the distances towards the shore increment. For long distances, this inefficiency becomes unacceptable and conversion to a direct current is deemed necessary.
A recently presented concept that aims to reduce the costs of offshore wind energy, is the concept of a large scale roll-out of interlinked offshore turbines, coordinated at an European level, including a so-called hub island. This artificial island facilitates converters, as well as a home base for engineers and large scale power storage. Technically, no big problems are expected with the construction of such artificial island. The major reason that could stop the hub island concept, is resistance from environmental organisations.
To predict ecological repercussions of an artificial island, the impact on hydrodynamic parameters most important to the bottom of the marine food chain are explored. The primary producers represent this foundation of the food chain, and are most affected by the island through changes in water stratification and residual currents. These parameters highly influence the light and nutrient availability, thereby regulating the primary production dynamics of the ecosystem.
By developing and applying the Three Dimensional Dutch Continental Shelf Flexible Mesh (3D DCSM-FM) model, the impact of an artificial island on the stratification and residual currents is explored for five case studies. Each case study comprises a 6km$^2$ cylindrical island, for different North Sea locations with distinct hydrodynamic properties.
The implementation of an artificial island alters residual currents up to 10km from its position. The location determines the impact pattern, but influences remain local without any large scale North Sea impacts. Since changes in nutrient availability are only expected for large scale residual current impacts, no significant alterations in primary production dynamics are to be expected.
The impact on stratification however, can have a significant influence on the dynamics of primary production. The originally well-mixed areas remain mostly unchanged, while islands in the more stratified regions can cause significant changes in absolute stratification up to 20km from the banks, and alterations in regimes or the seasonal onset timing up to 2.5km. The location and its hydrodynamic properties are paramount to the type of expected stratification impact, and proves to be an important design parameter for ecology around an offshore energy hub island in the North Sea.
2 island is introduced, approximately 30 km away from the Dutch coast. The effect on the nearshore wave climate is studied using the numerical model SWAN, while the resulting effect on the alongshore morphology is assessed using coastline model Unibest-CL+. The impact of future OWFs on the nearshore wave climate is found to be dependent on the size, shape, orientation and distance from the coast of the individual wind farms. Results show a mean decrease in significant wave height in the order of 1 – 2%. In addition, slight changes in wave direction are observed. The effect on wave climate reduces the alongshore sediment transport at the Dutch coast, by an order of 10% with respect to present values. This results in net-induced erosion, which requires nourishment. The study shows that the areas north of Zandvoort and Petten need the greatest nourishment volumes, in the range of 1.5 – 2.5 m3/m/year. This is an additional 1% on the current annual nourishment volumes supplied along the Dutch coast. The underlying study has proved to be effective in quantifying the chain of effects of OWFs and identifying potential hot-spots along the Dutch coast. The knowledge acquired from these effects can be used to optimize future OWF planning in relation to coastline maintenance policies.","large-scale offshore wind farms; North Sea; Dutch coast; energy island; coastal engineering; long-term morphodynamics; wave modeling; coastline modeling; coastal management; SWAN; Unibest-CL+","en","master thesis","","","","","","","","","","","","Civil Engineering","",""
"uuid:66a9227b-23a2-4303-a72d-d13a9021c1a4","http://resolver.tudelft.nl/uuid:66a9227b-23a2-4303-a72d-d13a9021c1a4","Flexible and energy self-sufficient floating cities in the North Sea","Hallulli, Anisa (TU Delft Architecture and the Built Environment)","Gommans, Leo (mentor); Schnater, Frank (mentor); Delft University of Technology (degree granting institution)","2018","Increasing urbanization and climate change are encouraging architects and engineers to use water as building land, adopting floating structures as a favorable solution. Floating architecture not only could help coastline cities to develop through seas and face sea level rise, but presents many other positive aspects among which particular interest has been developed in the concept of dynamic and energy self-sufficient cities.
The main object of the research is to define whether or not floating cities can realistically be energy self-sustained and in which capacity, by the use of today’s renewable energy production systems and by maintaining the positive aspects of a dynamic urbanism allowed by the presence of water.
This study concentrates on the Eridanos Delta and identifies the properties of the delta in terms of its progadation distance and sedimentation rate and compare different time models to the ones provided by Overeem (2001) and Kuhlmann (2008). Furthermore, studies the reservoir rocks in terms of their petrophysical properties and facies distribution. Moreover investigates the reasoning behind the shallow sediments gas accumulations and factors behind the concentration of all the discoveries around the A and B blocks. Lastly, constructs a 3D model of the reservoirs distribution in the study area and their properties by integrating the study results of geological, geophysical, petrophysical and reservoir engineering data.
Such results were achieved by interpreting a high resolution 3D seismic survey and 2D lines in combination with wells’ wireline logs and core data. Seismically, a total of 12 units were mapped to categories the successions (3.6 – 1.8Ma) that deposited post the Mid Miocene Unconformity. In addition, more than 20 wells were used to understand the reservoir properties in which seven wells have cores. Sedimentological aspects were assessed by studying the descriptions of cores and thin sections and the measurements of the core plugs. Gas accumulations were studied by evaluating the production data for gas and linking the gas to its source.
Contradiction between the rough concrete volumes defeated by asoft, ephemeral and seemingly delicate mass of water was the beginning of the research. Analysing the biggest territorial scale -the North Sea- the notion of “clashes” re-appeared. Historically, the North Sea was always an area of conflict. The constant fight between nature and the people trying to harness its power is it its very essence. In this context Atlantic wall seems to be the most contemporary example of the conflict on the area of the North Sea. Remains of Hitler’s plan stretch along the whole coast and in that sense are a direct translation of the territorial scale of the “war” into the architectural one- of a singular building- a bunker.
Yet, the conflict around the Atlantic war was in fact deemed to be a failure from the beginning. From the 15 000 bunkers planned only 6000 were realized by 1943. Then, suddenly, without any actual battle, the war ended. Observing the horizon was the only task of the soldiers until the war came to an end. The “absence” of the war is the essence of this narrative. Conditions of waiting, observing and experiencing the present moment surrounded by nature became a base for guidance and exploration.
Being part of theWadden Sea protected area, the location on the island of Terschelling emphasizes the contrast between the solid bunkers and dynamics of nature. Wadden Sea Islands are known for beautiful constantly changing dunes, inhabited by rich fauna and flora and influenced by regular tidal flows. One of many strong points on the island is the one located just next to the sea-shore, on top of the highest dune was chosen. It consisted of several buildings that were spread around that dune, serving primarily as an observation point.
Now, many years after the bunkers were placed there, some still remain. The passage of time and power of nature has however, changed them. They’ve became ruins. Some walls fell apart, some volumes tilted and moved, some were covered by the sand and overgrown by the grass. The “present ruinous state” of the remnants of the Atlantic Wall was understood here as the fundamental and relevant experience of the history itself and the starting point for the design. Instead of protecting against the forces, the project tries to use them as the main actors in the architectonic setting. The dominant, always present, unstoppable forces of nature are the base for design decisions. The way of
dealing with the knowledge was a strongly intuitive approach, mixing scientific knowledge with atmospheric perception of the nature. Inspiration for dealing with the composition, landscape and the ruins of the bunkers was taken from the archaeological excavation sites- the calculated geometric intervention against the vast masses of land in search of the “treasure” was to be used as the main concept in the design. The project relates to the landscape and experience of walking through the dunes. The wild nature is interpreted into rational concept. The different spaces and their architectonic qualities lead the visitor through subsequent spaces, constantly referring to the context.
The ritual experience begins by leaving the village or the parking area and entering through one of two gates. From a distance, only some of the bunker ruins and the skylights protruding through the sand are visible. Only when cutting through the ground and the building inside are the dimensions of the places revealed. The main buildings are almost all underground and are developed by taking from the architectural language of the bunkers.
The project tries to anticipate the flows of nature and takes the future time into consideration. Even though the building has a function to serve people at the beginning, it doesn’t have to be occupied all the time. It is a monument and its future role is to be there, in the constant condition of anticipation. Following the story of the bunkers that were left on sand to become ruins the concrete buildings are also going to stay and slowly deteriorate.
The cycle will close waiting for yet another chapter.
At the core of the colonial expansion was the concept of land appropriation that encouraged new forms of landuses . This act of reappropriating land was happening simultaneously at two scales - the global scale, where land in the colonies was being utilised to produce food products and raw materials, and on the domestic scale where land was being reappropriated to introduce new forms of industrial typologies. Within the city privately owned land was progressively sold or rented out to speculative house builders and merchants to build small scale mills factories , while on the other hand the small scattered strips of agricultural land in the rural were being enclosed and privatised to introduce large scale manufacturing industries. Over the years this gradual appropriation of rural land has led to its depopulation and has facilitated the decline of the small farmers, leaving valuable arable land in the hands of private owners.
Today, the decline of the small farms and the progressive privatisation of rural land has led to a severe lack of occupational and living diversity and has also dispossessed the rural of its means of agricultural sustenance . Large number of privatised rural farms in UK have shifted to commercial or animal based farms forcing the outsourcing of its increasing food demands to its former colonies. Currently 43% of the total food consumed by UK is imported by 2050, with a population of 75 million this number is predicted to go up by another 20%.
This project therefore focuses on food production within the UK, using two main aspects - the North sea :as its territorial frame of reference and the British colonial empire :as its backdrop . Together both these factors were crucial in developing a design proposal that explores both, the possibility of food sufficiency in a post Brexit future and speculative strategies to reimagine the rural as the new productive territory . Since food is a natural derivative of productive land, land becomes a key element of the project narrative. By overlaying new systems of production, occupation and habitat the project tries to both, establish new relationships between natural and man-made systems and also eschew the traditional distinctions between the city and the rural. Using a systematic sprawl the design tries to highlight the flexibility of a decentralised city to be able to accommodate and respond to future uncertainties without compromising on the sustainable and efficient utilisation of land.
By establishing new forms of ownership and occupation the design also becomes a tool to decolonize the rural land of its industrial remnants to make way for new forms of infrastructure and logistics . In this new city, the land is no longer a commodity, it is a mode of sustenance that is equally accessible to every citizen living in it. By internalizing the systems of production and distribution within this city the project tries to contest North sea’s current role as a facilitator of an unequitable decentralised global trade. The end result does not claim to be a definitive solution to the impending food crisis, rather it is a test of whether the revival and appropriation of one of the most archaic systems of land ownership and profit will be able to diminish the perilous consequences of years of consumerism that was a direct result of colonial industrialisation.
changes in the current European energy system to increase the share of
renewable energies and to reduce carbon emissions – from 1990 to 2050 by 90%.
The project Everything Remains Transformed intends to highlight how farreaching the transformative process from fossil energy sources, like crude oil
and gas coal, to renewable energies sources actually are. In the marine zone,
we will have to decommission platforms and pipelines at immense costs and
the coastline will eventually turn into a patchwork of abandoned harbours and
refineries. In the terrestrial zone, we will have to pull the plug from coal power
plants, while fossil-energy reliant businesses are running down, and citizens will
lose their current high-living standards.
The current energy system adds in this respect to the high ecological footprints of each country in the North Sea territory and requires drastic change in the light of resource management and estimated enormous population growth, according to Eurostat, among the nation states.
Everything Remains Transformed relies on parts of the remaining energy legacy
and the potential to transform its components. The project represents a new,
energetic system in the North Sea that aims to create one big territory with one
low footprint among all adjacent countries through collaboration. It demonstrates on the big scale, that a joint strategy will produce renewable energy to cover the territorial supply, reduces carbon efficiently and brings additional benefits beyond energy production.
A macro-regional strategy for the North Sea builds the overall framework for the
strategy. The aim of the European Union’s instrument is to jointly target common challenges with actors of various fields. On the small scale, in Aberdeen as a case study, I will showcase what influence big scale principles and spatial guidelines eventually have on the space and the societal and economic structure.","North Sea; Energy Transition; Macro-regional strategies","en","master thesis","","","","","","","","","","","","","",""
"uuid:ae051d49-e639-460f-ba92-7305857ba592","http://resolver.tudelft.nl/uuid:ae051d49-e639-460f-ba92-7305857ba592","Numerical modelling of the migration direction of offshore sand waves using Delft3D: Including underlying seabed topography","Leenders, Sjoerd (TU Delft Civil Engineering & Geosciences; TU Delft Hydraulic Engineering)","Aarninkhof, S.G.J. (mentor); Zijlema, M. (mentor); Walstra, D.J.R. (mentor); Borsje, Bas W. (mentor); Schouten, Jan-Joost (mentor); Hoekstra, R (mentor); Delft University of Technology (degree granting institution)","2018","The growth of the offshore wind industry results in intensive usage of the sandy seabed in the North Sea, currently and in the coming decades. Large-scale bed forms are present in shallow seas with sandy beds such as the North Sea. The most dynamic bed forms are sand waves. Due to their dynamic behaviour, sand waves can interact within offshore human developments and together with their dimensions pose a threat; e.g. decrease in navigation depth, exposure of submarine cables, interaction with foundations of offshore wind turbines and destabilization of bed protections. A thorough understanding of the dynamics can result in less risks for the offshore wind sector and therefore bring down the levelized cost of electricity from offshore wind.
Currently, sand wave field dynamics are investigated by data-driven analyses. These analyses are based on seabed surveys over preferable more than 10 years and are considered most reliable at the moment. However, these surveys are very costly and/or often not available. Complex numerical models may provide an approach to analyse sand wave dynamics in a cost and time efficient way, though two aspects have to be considered. Not all relevant processes regarding sand wave dynamics are yet understood. Furthermore, due to the large scale of sand wave fields in combination with the fine grid resolution required to model sand waves, large computational efforts form a difficulty for numerical modelling of sand wave fields. Previous numerical studies focused on reproducing the length and height of sand waves. The migration direction is the next step towards the full prediction of sand wave fields and the subject of this research.
Recent data-driven analyses showed migration directions of sand waves in opposite direction over small spatial scale, possibly related to underlying seabed topography. Understanding the governing processes of the migration direction of sand waves including underlying seabed topography is the focus of this research using the numerical process-based model Delft3D.
To this end, an idealized model is used in which underlying seabed topography (tidal sand bank) is included. For a symmetrical tidal velocity signal, it is shown that the presence of the tidal sand bank influences the hydrodynamics on the scale of sand waves. Horizontal tide-averaged flow towards the top of the tidal sand bank on both flanks is observed. This results in sediment transports and migration directions on both flanks of the tidal sand bank towards the top of the tidal sand bank. The horizontal tide-averaged flow pattern around the tidal sand bank is disturbed by the inclusion of a residual current. Sand wave migration on both flanks in the direction of the residual current is the result. Including the S4-tide constituent does not disturb the tide-averaged horizontal flow pattern around the tidal sand bank. However, the asymmetry of the tidal velocity signal enhances migration in the direction of the asymmetry.
Finally, it is shown that also for a more realistic model the transition in migration direction can be explained due to the presence of the tidal sand bank. The tidal sand bank influences the hydrodynamics by creating areas in which the tide-averaged sediment transport in the ebb direction are enhanced and areas in which the tide-averaged sediment transports in the flood direction are enhanced. In this way a transition in the migration direction over the tidal sand bank is observed. The migration directions from the model results and migration direction from data-driven analyses show a comparable transition over the tidal sand bank.
For further development of the NSI, more detailed research is needed.
The research gap is recognized that there is not sufficient research on proposing new HVDC grids in the North Sea considering optimization (e.g. following a cost-related objective) of different topology structures within a scope of six surrounding countries (BE, DE, DK, GB, NL and NO), with sensitivity tests regarding uncertainties (e.g. in meteorological condition, load, or industry development).
Therefore, the main research objective of this thesis project is to evaluate CAPEX, overall OPEX of participating countries and other operational performances (e.g. energy mix, nodal price, EENS) of possible topologies of HVDC network in the North Sea, including NSI (with a central North Sea Wind Power Hub at the Dogger Bank) and other two competitive topologies, considering uncertainties in green energy technology development, European coordination, load and meteorological condition (e.g. wind speed, solar radiation and hydrology).
Three specific research questions were studied in order to achieve the aforementioned research objective: How to define 3 topologies of the North Sea HVDC network with different feasible structures? What are the criteria to optimize each topology and to compare the topologies? What are the implications of each topology, when evaluated against a wide range of uncertainties, on the overall CAPEX and OPEX of countries involved?
The simulation considers the scenario in the year 2030. Software PowerGAMA and PowerGIM were used for operation simulation and topology optimization. When calculating OPEX throughout the lifetime of the equipment (assuming 30 years), the year 2030 is taken as a representative year and the 30-year OPEX is obtained by multiplying OPEX in 2030 by an annuity factor.
In short, 3 topologies of the North Sea HVDC grid, with hub-and-spoke structure (for the NSI), point-to-point structure and meshed (without central energy hub) structure, respectively, are defined. They are then optimized towards and compared for the lowest overall cost (i.e. the sum of CAPEX and OPEX including CO2 prices) throughout the lifetime.
Simulating under different uncertainties/selected critical scenarios (4 Visions from ENTSO-E’s Ten Year Network Development Plan which reflect different RES share target and European coordination level, and extreme RES inflow and load conditions), the optimized NSI design stays most socio-economically preferable (with lowest overall cost) topology.
It is also recognized that NSI is able to realize its expected functions, namely transmission of renewable energy, enhancement of system security and price convergence. On the other hand, launching of NSI brings in challenges such as grid congestion and benefit asymmetry.
Main contributions of this thesis include:
• Creation of the baseline model/dataset for European power system in 2030 as a background/environment for the North Sea HVDC grid planning;
• Design and optimization of the North Sea HVDC grid topologies in three different feasible structures;
• Verification of NSI’s advantage in cost saving, compared to two competitors, in 4 Visions reflecting different green energy transition and European coordination level, and under extreme RES inflow and load conditions;
• Verification of NSI’s function in improving energy sustainability, affordability and security;
• Realization of Non-Homogeneous Markov Chain algorithm in Excel to generate wind power inflow time series.","North Sea Infrastructure; North Sea Wind Power Hub; offshore HVDC grid; topology optimization; comparative assessment","en","master thesis","","","","","","","","","","","","Electrical Engineering","",""
"uuid:47c4598f-0100-4eb4-97a3-75266b0162bd","http://resolver.tudelft.nl/uuid:47c4598f-0100-4eb4-97a3-75266b0162bd","Nature enhancing opportunities for an artificial North Sea island: Opportunity study for the Dogger Bank","Frölke, Guus (TU Delft Civil Engineering and Geosciences; TU Delft Hydraulic Engineering)","Aarninkhof, Stefan (mentor); Houwing, Erik-Jan (mentor); van Druten, E.J. (mentor); Kuiper, Coen (mentor); Delft University of Technology (degree granting institution)","2018","Wind energy from the North Sea is one of the solutions to achieve the climate goals of the Paris agreement. The Dogger Bank, a North Sea sandbank, has a lot of potential for wind energy due to the relatively shallow location and good wind conditions. An artificial island creates even more opportunities, because alternating energy can be converted here into direct current. An island will also make the construction and maintenance of the windmills cost-effective. The Dogger Bank, however, is part of Natura2000 area, for which strict legislation applies. To design a stable island coastal defence, which contributes to the North Sea ecology, it is researched how natural value could be added to make the island licensable.
The flat oyster (Ostrea edulis) has been chosen as an umbrella species, a species that creates an environment in which a large group of other species can benefit. The disappearance of the present ecology by building an island can be counteracted by restoring an oyster habitat. To obtain the boundary conditions for a successful oyster bed, research was done into the relationship between the bed shear stress and the historic presence of oyster beds. The shear stress boundary condition for the highest significant waves was 119.8 N/m2 while the shear stress due to the average significant wave climate must stay between 2.5 and 10.3 N/m2. The orientation of the coastal protection, the depth, the profiles (as the presence of a reef or foreshore) and the chosen material are decisive factors for success of oyster beds. Concluded is that opportunities are available in the coastal defence. In typical cross-section are only few areas suitable. For the most exposed side (330-360ºN), it is opportune for oyster beds to grow around the toe and foreshore when located in water deeper than -25.0 m MSL. At the least exposed side (120-150ºN) this is -18.0 m MSL. Reefs and prolonged foreshores are expected to be efficient for creating larger nature enhancing surfaces.
The design and three-dimensional consequences of the suggested measures are recommended to study into detail. In addition, the biotic factors and the method of initiation of oyster beds will have to be further investigated to obtain more information about successfully creating oyster beds around an island on the Dogger Bank.
In June 2016, Dutch transmission system operator TenneT proposed the Hub and Spoke concept. It is an alternative method to connect offshore wind farms with the onshore grid and makes the parameter distance to shore far less important. Basically, the concept combines offshore wind farms with interconnector cables. An artificial island is created somewhere in the centre of the North Sea which is surrounded by offshore wind farms, thereby being far away from the crowded coastlines while profiting from near shore conditions. The interconnector cables subsequently transport the generated electricity to shore.
Dogger Bank is the envisioned location for the Hub and Spoke concept. The area contains strong winds, shallow water conditions and is centrally located. However, the unique characteristics of the shallow sandbank make it also very favourable to a variety of species. The area is therefore appointed Natura 2000 territory and could cause major resistance from environmental organisations. The general consensus amongst environmental organisations is not yet known, but industry experts indicate this as the major reason which could stop the Hub and Spoke concept from being realised on Dogger Bank.
The objective of this research is to determine the optimal location for the Hub and Spoke concept in the North Sea. The concept feasibility has never been determined and it is not even certain if Dogger Bank is the most beneficial location, while the location contains a very large risk. Therefore, the site selection model is created. The model contains input data from metocean conditions and electricity markets, which makes it possible to calculate the feasibility of the Hub and Spoke concept for every location in the North Sea. The result is a contour plot with the net present value of the Hub and Spoke concept, which shows the optimal location in the North Sea.
The Hub and Spoke concept is divided into five components to determine the influence of certain conditions on cost or revenue and to compare the components between each other. The artificial island and offshore wind turbines are primarily influenced by water depth, while the subsea interconnector cost is mainly influenced by the cable capacity and length of the cable. The optimal location for the island and offshore wind farms with respect to cost is thus along the shallow coastlines or at Dogger Bank, while the optimal location for the subsea interconnector cables is determined by the minimum total cable length. This point is equal to the centre of gravity of the countries surrounding the North Sea and is located just above the Netherlands and Germany.
In terms of revenue, the wind conditions are normative for the production and revenue of offshore wind farms and interconnectors derive their congestion rents from electricity price differences between countries. Offshore wind farms generate most electricity in the northeastern part of the North Sea where the wind conditions are strongest. This negatively impacts the generated revenue from subsea interconnectors as the cable is used more often for offshore wind energy. Interconnector revenue of the Hub and Spoke concept is therefore lowest at locations with the strongest wind speed, but in total the highest revenue is generated. A comparison between these components for four various locations is presented in Figure 1.
XXX
Offshore wind farms are both in cost and revenue the major component in the Hub and Spoke concept. The optimal location is thus expected to be found in areas with shallow water depths and high wind speeds. Finally, each component with its cost and revenue has been determined and can be merged in the site selection model to determine the feasibility of the Hub and Spoke concept in the North Sea. See Figure 2.
XXX
It can be concluded that the highest net present value for the Hub and Spoke concept is situated along the coastline of Denmark and Germany. However, these locations are known to be very crowded and the reason to investigate alternative locations in the first place. Dogger Bank and the northwest of Denmark are two very interesting alternatives. Dogger Bank is very shallow with depths of 10 m, while the northwest of Denmark is slightly deeper with 20 m but contains roughly 10% higher wind speeds. Both locations are primarily free from other marine uses, although Dogger Bank is protected Natura 2000 territory and therefore contains a very large risk. It is therefore advised to construct the Hub and Spoke concept at the northwest side of Denmark.","Hub and Spoke; offshore wind energy; TenneT; artificial island; North Sea; interconnector","en","master thesis","","","","","","","","","","","","Civil Engineering | Hydraulic Engineering | Coastal Engineering","","55, 3.7"
"uuid:b96654aa-db0a-43e1-bd3c-345461f75901","http://resolver.tudelft.nl/uuid:b96654aa-db0a-43e1-bd3c-345461f75901","Modelling, control and stability analysis of the COBRAcable project integrated in the Dutch transmission system: Evaluation of the performance of the controllers","Karaolanis, Aris (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Electrical Sustainable Energy)","van der Meijden, M.A.M.M. (mentor); Mor, A. R. (mentor); Rueda, José L. (mentor); Alefragkis, Alex (mentor); Perilla Guerra, A.D. (mentor); Delft University of Technology (degree granting institution)","2017","The COBRAcable project is one of the major interconnectors being constructed in the North Sea, connecting the Netherlands with Denmark. It is a 325 km submarine cable which will have the ability to transfer 700 MW. The importance of the interconnector is manifold: to facilitate the exchange of renewable energy coming from the onshore Danish power system. Since electricity demand and supply of wind energy is geographically spread an adequate transmission capacity is essential for the growth of renewable energy. The link will also provide a strong connection that will enhance the security of supply in the Northwestern European region. That is in line with the ambitions of the EU for a stronger interconnected European electricity transmission grid and it will be a backup in case of breakdowns.
Moreover, it will enhance the internal European electricity market. COBRAcable will contribute to the development of the internal European electricity market and specifically contribute to the further investigation of the Northwest European electricity market. Lastly, COBRAcable has been granted a European subsidy for researching and developing activities necessary for the connection of wind farms to the cable.
The main focus of the present thesis is to create a RMS model of the COBRA cable project in PSSE software. The starting point of the master thesis project was a basic model of a VSC station which consisted of the basic VSC converter controllers: the active power controller, the reactive power controller, the AC voltage controller and the DC voltage controller. Gradually, the active and reactive power controllers were upgraded in order to support the special functions of the COBRAcable project. Also, an equation regarding the injection of reactive current was added to implement the fault ride through capability of the converter. In the end, the responses of the final model created throughout this master thesis project were compared against the responses of the model built in Powerfactory, which was created in more detail and was already compared against the results of the EMT model in PSCAD.
The modelling framework for VSC – based HVDC transmission system was initially developed and tested in a benchmark system consisted of two areas. Both areas had three buses connected in a meshed configuration and the performance of the controllers mentioned above was evaluated there. Following the benchmark system, the modelling framework was then tested with a reduced model of the Dutch power system around the Eemshaven region.
Different tests were defined in order to evaluate the suitability of the model and in more details to evaluate the performance of the controllers. To evaluate the performance of the active power controller several cases were introduced associated with the special functions of the COBRAcable regarding the regulation of active power. The reference of the reactive power was changed and the performance of the reactive power controller was tested while using different ramping rates. Moreover, the voltage at the point of common coupling was changed in order to assess the performance of the AC voltage controller. Finally, the equations regarding the injection of reactive current were used to evaluate the fault ride through capability of the converter.
From the simulation results, it was observed that the active and reactive power controllers were able to follow the changes of the reference power quite stably regardless the different ramping rates that were used. The reference changes created a dynamic behavior regarding the performance of the AC voltages of the buses in the Dutch power system. The investigation regarding the AC voltage controller led to the conclusion that there is a limit on how much you can increase and decrease the voltage at the PCC. The equations associated with the fault ride through capability have shown that the converter is actually trying to inject reactive power when the voltage has dropped below certain levels. In the end, the creation of a user – written model of the COBRA cable project in PSSE added an increased level of complexity. The absence of block diagrams with their respective signals as well as the required knowledge of the software made the translation of the control structure of the VSC station from the Powerfactory model difficult.
been deposited by Eridanos fluvio-deltaic system, draining the Fennoscandian and Baltic shield through the present Baltic Sea. Three successful producing fields - A12-FA (2007), F02a-B-Pliocene (2009) and B13-FA (2011)- and
five under development have triggered the conduction of several studies in the offshore area. However the deltaic environment has been characterized as highly complex owing to its influence by the onset of Northern Hemisphere
Glaciation and thus the processes that governed the system have not become entirely understood. Enhanced cooling followed by the waxing and waning of the glaciers during warmer periods had an immediate impact on sediment
supply, accommodation space and mineralogical input. Although the sediments have been studied in terms of chrono-biostratigraphy, no systematic investigation with respect to the three main aforementioned factors as well
as the regional sequence stratigraphy and its link to the reservoir deposits has been made up to date. Therefore, this study employed sequence stratigraphy as a method to examine Eridanos conditions of deposition, investigate the
interplay between accommodation space and sediment supply and explore the nature of the gas-bearing reservoir sediments. The adopted methodology is comprised of two basic pillars, observation and interpretation. The first
records as clearly as possible the observations arise from the sequence analysis while the second extracts the meaningful information and interprets it in terms of temporal and spatial concepts. Using 2D seismic and well log data the basic observations were the stratal terminations, stacking patterns, seismic facies and the shoreline trajectory.
Seismic and well log interpretation showed that the delta experienced multiple events of sea level fall which forced the shoreline to regress basinward and caused sediment erosion or non-deposition. These events are bounded
by nine time-significant surfaces of subaerial unconformities which constitute the depositional sequences. Normal regression comprised the dominant depositional trend, combined with aggrading-prograding patterns, leading to
characteristic alternations of highstand and lowstand system tracts. Three main depositional environments which correspond to open marine turbidites (submarine lobes), delta front and delta top were identified from well logs,
core descriptions and the seismic facies analysis. The study suggests that the shallow gas is located in the alternations of silty-sandstones and claystones of the delta plain which comprise the vertical stacking of parasequence
topsets within the highstand- lowstand system tracts. Reconstruction of the relative sea level changes and sedimentation rates was made based on a technique introduced by this study. It uses the average thickness of each seismic
unit in order to interpolate time between the three known absolute ages obtained by the literature. The graphs showed that the accommodation space was generated by a low rate of sea level rise while sedimentation rates were
increasing over time. However the scarcity of time constrains in combination with the uncertainty in the estimation of seismic volumes resulted in a low resolution outcome. A comparison between the findings of this study and
those of the existing literature was made. The overall depositional trends and conditions seem to be in accordance with the other surveys. Nonetheless the proposed interplay between accommodation and supply can be assigned as
local since the examined area is limited compare to areas studied in literature. Limitations are traced in the quality of the 2D seismic data hampering the observation regarding the relation between the reflectors and the surfaces.
Consequently, the study offers an insight into the conditions under which the gas-bearing deltaic sediments were deposited and tries to place them in the established sequence stratigraphic framework. Also it provides information
regarding the distribution of the deltaic environments and identification of the reservoir rocks within each setting. The resulting interpretation can be used for prediction of the reservoir formations since the genetically-related
packages where they were identified are distributed in a predictable manner within a sedimentary basin.","Seismic interpretation; Sequence Stratigraphy; Shallow gas sediments North Sea; Sediment supply; Accommodation space; Eridanos Delta; Applied Geology","en","master thesis","","","","","","","","","","","","","",""
"uuid:6471642b-95c1-4b93-986b-2de631f2ff8e","http://resolver.tudelft.nl/uuid:6471642b-95c1-4b93-986b-2de631f2ff8e","Decommissioning platforms on the North Sea:: Guidelines on heavy lift vessel selection","Boltje, Diedert (TU Delft Mechanical, Maritime and Materials Engineering)","Hopman, J.J. (graduation committee); Coenen, J.M.G. (mentor); Veeke, H.P.M. (graduation committee); van der Sanden, P.M.L. (mentor); Delft University of Technology (degree granting institution)","2017","This thesis contains the model development of a simulation model, to aid the selection of a heavy lift vessel for a North Sea decommissioning project. The model considers fixed steel platforms with maximum topside weight of 1.400 [tons].","Decommissioning; North Sea; Heavy Lift Vessel; Monte Carlo simulation model","en","master thesis","","","","","","","","2022-01-21","","","","","",""
"uuid:4439ccef-1079-43ec-96b5-d143eda4e23d","http://resolver.tudelft.nl/uuid:4439ccef-1079-43ec-96b5-d143eda4e23d","Identifying options for the multi-terminal expansion of the COBRAcable","Pieper, J.T.","Rueda Torres, J.L. (mentor)","2016","A meshed North Sea offshore electricity grid with high renewable energy penetration, as envisioned by the European Commission, is still at its infancy. Currently, point-to-point high-voltage DC interconnections across borders are already being implemented successfully, but the next steps of expanding these interconnectors with additional terminals to connect to offshore wind farms or other energy facilities are still being researched. This MSc research evaluates the case of the COBRAcable, an interconnector between Denmark and the Netherlands. The COBRAcable presents an interesting and unique case as it the first of its kind and likely involves the expansion of the interconnector in Germany territory. Large uncertainties are present due to different national regulatory regimes, diverse groups of stakeholders with different interests, and stochastic uncertainties due to the variability of renewable energy sources. A socio-economic framework has been designed to address the interdisciplinary nature of the problem of multi-terminal expansions. Scenarios of alternate futures are developed, and Monte Carlo analysis is performed to address the future energy characteristics and stochastic uncertainties respectively. It consists of a linear optimal power flow model where a simplified grid is being tested under multiple expansions that are selected in an expansion portfolio. The results will be quantitative costs and benefits of expansions as compared to a base case. Complementary, a qualitative stakeholder analysis is carried out to address the regulatory uncertainties that are not accounted for by the model.","COBRAcable; cost benefit analysis; interconnector; long-term transmission expansion planning; Monte Carlo; multi-terminal expansion; North Sea grid; offshore HVDC; stakeholder analysis","en","master thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","Intelligent Electrical Power Grids","",""
"uuid:fa25092a-5ac7-4b8e-822c-307f509e850d","http://resolver.tudelft.nl/uuid:fa25092a-5ac7-4b8e-822c-307f509e850d","Source term balance in a severe storm in the Southern North Sea","van Vledder, G.P. (TU Delft Environmental Fluid Mechanics; Van Vledder Consulting); Sander, Sander Th (BMT ARGOSS); McConochie, Jason D. (Shell Global Solutions International B.V.)","","2016","This paper presents the results of a wave hindcast of a severe storm in the Southern North Sea to verify recently developed deep and shallow water source terms. The work was carried out in the framework of the ONR funded NOPP project (Tolman et al. 2013) in which deep and shallow water source terms were developed for use in third-generation wave prediction models. These deep water source terms for whitecapping, wind input and nonlinear interactions were developed, implemented and tested primarily in the WAVEWATCH III model, whereas shallow water source terms for depth-limited wave breaking and triad interactions were developed, implemented and tested primarily in the SWAN wave model. So far, the new deep-water source terms for whitecapping were not fully tested in shallow environments. Similarly, the shallow water source terms were not yet tested in large inter-mediate depth areas like the North Sea. As a first step in assessing the performance of these newly developed source terms, the source term balance and the effect of different physical settings on the prediction of wave heights and wave periods in the relatively shallow North Sea was analysed. The December 2013 storm was hindcast with a SWAN model implementation for the North Sea. Spectral wave boundary conditions were obtained from an Atlantic Ocean WAVEWATCH III model implementation and the model was driven by hourly CFSR wind fields. In the southern part of the North Sea, current and water level effects were included. The hindcast was performed with five different settings for whitecapping, viz. three Komen type whitecapping formulations, the saturation-based whitecapping by Van der Westhuysen et al. (2007) and the recently developed ST6 whitecapping as described by Zieger et al. (2015). Results of the wave hindcast were compared with buoy measurements at location K13 collected by the Dutch Ministry of Transport and Public Works. An analysis was made of the source term balance at three locations, the deep water location North Cormorant, the inter-mediate depth location K13 and at location Wielingen, a shallow water location close to the Dutch coast. The results indicate that at deep water the source terms for wind input, whitecapping and nonlinear four-wave interactions are of the same magnitude. At the inter-mediate depth location K13, bottom friction plays a significant role, whereas at the shallow water location Wielingen also depth-limited wave breaking becomes important.","Nonlinear interactions; North Sea; Source term balance; SWAN; Wave modelling; Whitecapping; Wind input","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:8681695d-7c4d-4c3c-b4c8-ea027fcb229c","http://resolver.tudelft.nl/uuid:8681695d-7c4d-4c3c-b4c8-ea027fcb229c","Gas condensate allocation based on an equation of state model","van Breukelen, I.","Jansen, J.D. (mentor)","2016","The current allocation method for gas condensates in the offshore gas fields (of Shell and partners) of the Southern North sea is unreliable. The allocated values of the gas condensates are physically not possible. The current allocation method shows condensate gas ratios that are extremely varying (and sometimes increasing) over time, while it is known that gas condensate ratios either stay constant or decrease over time (decreasing reservoir pressure). The method that is currently used for condensate allocation is based on unreliable samples and measurements. The method provides a relative allocation by using reconciliation factors to compensate for the difference of onshore and offshore measurements. This thesis explores alternative condensate allocation methods, and proposes that using the thermodynamic behaviour of fluids will increase the accuracy of gas condensate allocation. The properties of the fluids differ per field and can be described by the equation of state of Peng-Robinson. The properties of the fields come from PVT reports. The PVT reports are based on experiments on samples that were taken before a field started producing. The thermodynamic models of the reservoir fluids were made with a software package called PVTSIM that is based on the equation of state. The fluid models were validated with measured data at an offshore slugcatcher. The measured data had some uncertainty factors, but did show a good match with the modelled results. The new model is used to calculate the total amount of produced condensate. This calculated total amount is compared with the actual measured produced amount of condensate. The difference between both volumes is less than 2\%. The currently allocated condensate is also compared with the calculated condensate, which shows big differences. The new method based on the equation of state of the reservoir fluids yields accurate results with physically expected trends.","gas condensate; allocation; Southern North Sea; equation of state; Peng Robinson; PVTSIM; hydrocarbons","en","master thesis","","","","","","","","2026-08-26","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:0b395409-69cc-40dc-b787-49352ad1b95e","http://resolver.tudelft.nl/uuid:0b395409-69cc-40dc-b787-49352ad1b95e","Sea surface height variability in the North East Atlantic from satellite altimetry","Sterlini, Paul (Royal Netherlands Meteorological Institute (KNMI)); de Vries, Hylke (Royal Netherlands Meteorological Institute (KNMI)); Katsman, C.A. (TU Delft Environmental Fluid Mechanics)","","2016","Data from 21 years of satellite altimeter measurements are used to identify and understand the major contributing components of sea surface height variability (SSV) on monthly time-scales in the North East Atlantic. A number of SSV drivers is considered, which are categorised into two groups; local (wind and sea surface temperature) and remote (sea level pressure and the North Atlantic oscillation index). A multiple linear regression model is constructed to model the SSV for a specific target area in the North Sea basin. Cross-correlations between candidate regressors potentially lead to ambiguity in the interpretation of the results. We therefore use an objective hierarchical selection method based on variance inflation factors to select the optimal number of regressors for the target area and accept these into the regression model if they can be associated to SSV through a direct underlying physical forcing mechanism. Results show that a region of high SSV exists off the west coast of Denmark and that it can be represented well with a regression model that uses local wind, sea surface temperature and sea level pressure as primary regressors. The regression model developed here helps to understand sea level change in the North East Atlantic. The methodology is generalised and easily applied to other regions.","North East Atlantic; North Sea; Sea level change; Sea surface variability","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:620bc4f5-d1ba-42b3-b4a7-5cd389d4e331","http://resolver.tudelft.nl/uuid:620bc4f5-d1ba-42b3-b4a7-5cd389d4e331","Episodic density-induced current velocities at the Gemini offshore wind park","Claessens, C.","Pietrzak, J.D. (mentor)","2016","This thesis investigates the origin of observed current velocities at the Gemini offshore wind farm in 2015. Currents have been measured of 1.2 m/s while, based upon tidal and storm predictions, currents of only 0.7 m/s were expected. The aim of this research is to gain insight into the origin of these higher currents, taking into account the physical oceanography at this location. We find that these high currents measured in August are forced by baroclinic currents. Stratification was present at a measurement ship, 32 km northeast from Gemini. In addition, satellite imagery shows Gemini to be located in a region with fronts, between warm water from the Wadden Sea and colder water from the North Sea. In fact, a tidal mixing front is formed on top of the already established saline stratification [Van Aken, 1986]. The origin of fresh water is found to be from sluices discharging onto the Wadden Sea. Prior to the period with high currents a pulse of fresh water is discharged onto the Wadden Sea. Followed by the lowest winds recorded in 2015, an optimal climate is formed in which fronts can travel offshore. This is supported by the satellite imagery. In addition, density-induced currents are calculated based upon the mathematical model of Heaps [1972]. The analysis if the data suggests that density driven currents of 0.4 m/s are generated in August, which combined with the tide can give 1.2 m/s currents.","Physical oceanography; North Sea; Density driven currents; Baroclinic currents; Fresh water currents; Remotely sensed SST imagery","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Environmental Fluid Mechanics","",""
"uuid:fe80ba99-c08e-4dd3-9919-248bac4ebe72","http://resolver.tudelft.nl/uuid:fe80ba99-c08e-4dd3-9919-248bac4ebe72","Estimating decadal variability in sea level from tide gauge records: An application to the North Sea","Frederikse, T. (TU Delft Physical and Space Geodesy); Riva, R.E.M. (TU Delft Physical and Space Geodesy); Slobbe, D.C. (TU Delft Physical and Space Geodesy); Broerse, D.B.T. (TU Delft Physical and Space Geodesy); Verlaan, M. (TU Delft Mathematical Physics; Deltares)","","2016","One of the primary observational data sets of sea level is represented by the tide gauge record. We propose a new method to estimate variability on decadal time scales from tide gauge data by using a state space formulation, which couples the direct observations to a predefined state space model by using a Kalman filter. The model consists of a time-varying trend and seasonal cycle, and variability induced by several physical processes, such as wind, atmospheric pressure changes and teleconnection patterns. This model has two advantages over the classical least-squares method that uses regression to explain variations due to known processes: a seasonal cycle with time-varying phase and amplitude can be estimated, and the trend is allowed to vary over time. This time-varying trend consists of a secular trend and low-frequency variability that is not explained by any other term in the model. As a test case, we have used tide gauge data from stations around the North Sea over the period 1980-2013. We compare a model that only estimates a trend with two models that also remove intra-annual variability: one by means of time series of wind stress and sea level pressure, and one by using a two-dimensional hydrodynamic model. The last two models explain a large part of the variability, which significantly improves the accuracy of the estimated time-varying trend. The best results are obtained with the hydrodynamic model. We find a consistent low-frequency sea level signal in the North Sea, which can be linked to a steric signal over the northeastern part of the Atlantic.","decadal variability; North Sea; sea level variability; tide gauge","en","journal article","","","","","","","","2016-10-31","","","Physical and Space Geodesy","","",""
"uuid:a210fc5f-a2e2-43f0-b754-b41e8740d487","http://resolver.tudelft.nl/uuid:a210fc5f-a2e2-43f0-b754-b41e8740d487","Predicting currents at the ""Gemini"" wind farm: Analysis of Triaxys ADCP-data","Roest, Bart (TU Delft Civil Engineering & Geosciences; TU Delft Hydraulic Engineering)","de Boer, G.J. (mentor); de Schipper, M.A. (mentor); Delft University of Technology (degree granting institution)","2015","Van Oord is currently building the Gemini Wind farm in the North Sea. It is located 80km North of Schiermonnikoog. Before execution started some wave and current analysing buoys have been deployed to investigate the currents on the location of the wind farm for workability and insurance purposes. In this report the ADCP-current data will be analysed.
The major finding is that maximum tidal currents do not occur in winter but in summer, since the tidal currents are influenced more by stratification than by wind influences.
This report has been written as part of my internship at Van Oord DMC, in Rotterdam.","Tidal currents; Tidal analysis; ADCP; Gemini; Density driven currents; North Sea","en","student report","","","","","","","","","","","","Civil Engineering | Environmental Engineering","","54.0403, 5.8850"
"uuid:7b269752-5e1e-4e45-bc91-5415d6e5221c","http://resolver.tudelft.nl/uuid:7b269752-5e1e-4e45-bc91-5415d6e5221c","Teamwork on the North Sea","Satolli, J.","Hermans, L.H. (mentor); Thissen, W.A.H. (mentor); Hemmes, K. (mentor)","2015","The main focus of this thesis has been to gain an understanding on the key challenges for self-organization between the relevant stakeholders necessary for rolling out a North Sea Offshore Grid. The North Sea Offshore Grid (NSOG) is an important component in the realization of the renewable energy potential in different European countries. Up till now no commonly accepted strategy has been composed for rolling out this offshore grid in a coordinated way. This lack of a commonly accepted strategy is affecting the trust and progress in international collaboration and in the coordinate development of national visions. This lack of coordination increases the risk for lock-in effects leading to sub-optimal development pathways. The current research and practices on the valuation of optimal grid configuration has been based on the comparison of costs and benefits of the different policy options. This research has taken a different approach, and has looked at the different stakeholder perspectives on developments in the offshore wind industry. Results show multiple challenges currently blocking a coordinated NSOG rollout. One of the major challenges is the discrepancy and the lack of common ground between stakeholders on the monetization, composition and distribution of these costs and benefits. These disagreements on costs and benefits are not likely to be resolved by yet another improved effort at classic cost-benefit analysis. Also, the identification of costs and benefits for individual projects lacks the synergy effects of a total grid. Other important challenges identified are the lack of profitability and high risk level of making (anticipatory) investments necessary to facilitate a future grid expansion and the lack of trust between the different stakeholder on future commitment and collaboration. The combination of these challenges has resulted in an equilibrium of stakeholders defecting and performing free-riders behavior, waiting for others to take the risk and invest in sufficient offshore wind capacity necessary for allowing for profitable business case to be set up. It has thus been argued that focus of the current discussions should shift from identifying the most efficient project or grid configuration, towards a discussion about ways how to increasing the willingness of Member States to express their long-term financial commitment towards the development of the grid and accept the investment risks by putting the costs and benefits of the NSOG in a broader perspective of potential gains for the individual Member States. This research has used the SES-framework and the self-organization theory from Ostrom as tools for structuring and reflecting on the results. However, both the framework as the theory have been initially developed for ecological systems. Since the North Sea Offshore Grid is a Social Technical System (STS), a second line of research which has been presented in this report is related to the applicability of both the framework and the theory on comparable STS.","offshore wind; North Sea Offshore Grid; self-organization; stakeholder perceptions; technological and institutional integrations; SES-framework","en","master thesis","","","","","","","","2015-03-29","Technology, Policy and Management","Systems Engineering, Policy Analysis and Managment","","Energy & Industry","",""
"uuid:35e168b6-4d39-4e12-becd-4bbd701372d0","http://resolver.tudelft.nl/uuid:35e168b6-4d39-4e12-becd-4bbd701372d0","Numerical modelling of the growth of offshore sand waves: A Delft3D study","Choy, D.Y.","Stive, M.J.F. (mentor); Hasselaar, R.W. (mentor); Borsje, B.W. (mentor); Hoekstra, R. (mentor); Blom, A. (mentor); Ooi, S.K. (mentor); Cheong, H.F. (mentor); Raaijmakers, T.C. (mentor)","2015","Offshore sand waves of several meters high and hundreds of meters long are formed in shallow seas due to the tidal currents. These sand waves can, amongst others, influence the burial depth of cables of offshore wind farms and obstruct navigation channels. For the Far Large Offshore Wind programme (FLOW), one of the goals of Deltares is to increase the knowledge on sand wave growth and behaviour. Since only a limited amount of bathymetrical data is available in these offshore areas, numerical models can give some insights to predict sand wave development. So far, all numerical models used to estimate the growth of offshore sand waves predict unrealistic values for either the sand wave height or the sand wave length. These values are highly overestimated. Most models initially predict a sand wave length that is realistic under the modelled conditions. This is the length of the fastest growing mode (LFGM). However, when extending the model simulation time, the sand waves grow up to the length of the entire computational domain. When limiting the length of the domain to one sand wave length, the sand waves become extremely high. No model has yet been able to correctly predict both the wave length and the wave height. The main objective of this study was to understand the processes behind sand wave growth and modelling the sand waves up to an equilibrium state. The effects of two different aspects on the growth of offshore sand waves in a sand wave field were studied. First, the impact of the bed slope effect was assessed, since in previous studies the influences of this parameter were not studied in much detail. The bed slope effect is the (numerical) phenomenon where sediment grains are transported downhill more easily than uphill. This parameter is very important under the applied conditions and has a strong influence on the model predictions. Secondly, the influence of different initial bathymetries on the growth of the sand waves was determined. Both initially random and large sinusoidal beds were used. Long-term model simulations (morphological time > 200 years) were run to assess the impacts of the studied aspects on a potential equilibrium. Equilibrium is found for growing sand waves, when the bed with sinusoidal perturbations equal in length to the LFGM is applied. With these sinusoidal perturbations, the bed slope effect only influences the growth rate and the shape. The equilibrium height found is similar to that predicted with other numerical models where the domain has the length of one sand wave and is, thus, overestimated. In both cases, the equilibriums are forced. The sand waves cannot grow further in length and have reached a maximum height for the corresponding wave length. Model simulations with other initial beds led to even larger and longer sand waves. Though, at some point during the simulation, a mean wave length of approximately the length of the fastest growing mode is dominant in the sand wave field. Eventually, after the modelled 750 years, no equilibrium is found with these initial beds as the increase in wave length or wave height is on-going. This suggests that essential processes are not taken into account or are modelled incorrectly.","sand waves; numerical modelling; modelling; North Sea","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4cae9d4c-02f1-497c-b676-e3c00067baf9","http://resolver.tudelft.nl/uuid:4cae9d4c-02f1-497c-b676-e3c00067baf9","Improving jack-up capabilities","Dimitriou, A.","Metrikine, A. (mentor)","2014","So far jack-ups have successfully operated in depths of 80 to 100 m and some are capable of operating in water depths of up to 150 m. In order to circumvent the depth limitation, it was suggested by Heerema Marine Contractors (HMC) that a base could be designed with the ability to support a jack-up rig, thereby increasing its operational depth capability. Such a support structure for jack-ups (named SSfJ) that can possibly be mobilized and demobilized by an HMC vessel would allow HMC to offer its services to another part of the Oil and Gas industry, the Drilling and Workover sector. A first investigation into the feasibility of this idea is carried out in this thesis. The focus of the thesis is placed on determining whether a 3-legged North Sea drilling jack-up can potentially survive on a SSfJ and on the calculation of the structural characteristics of the SSfJ that are required for enabling a jack-up to do so. The first step in this research was to verify if there is a commercial driver for the SSfJ. Therefore a market research took place which focused on the North Sea offshore drilling industry and showed that there is a need for high spec and deep water jack-ups and a great need for reduction in drilling costs. The driver was therefore clear, namely that there is a need to design a SSfJ that will enable jack-ups to operate in deeper water without much increase in costs. Then, based on market information it was decided to consider a SSfJ that would add 30m of water depth capability to the GustoMSC CJ 70 jack-up type. The main (technical) part of the thesis focused on identifying how the jack-up integrity will be influenced when it is placed on the SSfJ and what structural characteristics the SSfJ should have in order to enable a jack-up to survive on it through the harshest North Sea environmental conditions. The influence of the use of the SSfJ was assessed via reasonable assumptions that were then verified with analysis in the software SACS. The required structural characteristics of the SSfJ were identified as the SSfJ stiffness and rotational fixity at the SSfJ – jack-up interface. Recommended values for these characteristics were identified via an iterative procedure that includes a simplified dynamic analysis method that uses a Dynamic Amplification Factor. The results were then verified with a more accurate method that employs the time domain simulations in SACS. The outcome of the research is that the jack-up integrity is not influenced negatively by the use of SSfJ and that if the SSfJ has the recommended structural characteristics then the jack-up can survive the harshest environmental conditions in the North Sea.","jack-up; North Sea","en","master thesis","","","","","","","","2014-09-01","Mechanical, Maritime and Materials Engineering","Offshore and Dredging","","Bottom Founded Structures","",""
"uuid:cb355c8e-836e-4ee0-b481-1469980cb7a1","http://resolver.tudelft.nl/uuid:cb355c8e-836e-4ee0-b481-1469980cb7a1","An Idealized Meteorological-Hydrodynamic Model for Exploring Extreme Storm Surge Statistics in the North Sea","Van Ledden, M.; Van den Berg, N.J.F.; De Jong, M.S.; Van Gelder, P.H.A.J.M.; Den Heijer, C.; Vrijling, J.K.; Jonkman, S.N.; Roos, P.C.; Hulscher, S.J.M.H.; Lansen, A.J.","","2014","This paper explores an alternative method to determine extreme surge levels at the Dutch Coast. For this exploration, specific focus is on the extreme water level at Hoek van Holland, The Netherlands. The alternative method has been based on a joint probability model of the storm characteristics at the North Sea. The intent of this method is to provide a better physical and statistical insight into the effects of meteorological characteristics on surge levels and surge duration, especially for surges of more extreme storms currently not captured in existing water level measurement records. The meteorological part is an analytical parametrical model based on the Holland model for hurricanes, which results in time- and space-varying wind and pressure fields of North Sea storms. The wind and pressure forcing is then applied in the hydrodynamic model which numerically solves the nonlinear depth-averaged shallow water equations in a one-dimensional domain from the edge of the continental shelf between Scotland and Norway to Hoek van Holland. Validation against wind observations from historical storms at one location in the entire domain shows good results. Results of the calibrated surge level model are reasonable if peak surge levels are considered. The surge duration, however, is underestimated by the model. Next, the model has been applied to define extreme surge levels using Monte Carlo Analysis. Probability density distributions for the storm parameters based on historical data have been used as input. The computed surge level (including tide) with a statistical return period of 10,000 years appears to be close to the value from statistical extrapolation of surge levels. The output also indicates that the average duration of computed surges with a return period of 10,000 year is roughly two hours longer than the storm duration currently adopted.","storm surge levels; North Sea; joint probability analysis; extreme value statistics; ICCE 2014","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:cde15374-b7cc-4823-898e-ecc1b12aba8a","http://resolver.tudelft.nl/uuid:cde15374-b7cc-4823-898e-ecc1b12aba8a","A modelling study on the residual circulation in the North Sea, with the focus on water fluxes through the Strait of Dover","Van der Linden, L.G.","Pietrzak, J.D. (mentor); Van der Kaaij, T. (mentor); De Boer, G.J. (mentor); Verlaan, M. (mentor); Zijlema, M. (mentor)","2014","In this master thesis the residual circulation in the North Sea is investigated. It has been shown that the numerical models used in this thesis (DCSMv5 and DCSMv6) give a rather low representation of the actual circulation pattern in the North Sea. The dominating forces which cause residual currents in the North Sea are the tidal forcings, meteorological forcings and density variations. Their variability over the whole domain, as well as their interaction with bottom topography and the earth’s rotation, leads to a variety of different processes. Since it is difficult to quantify to total transport over the whole North Sea, the focus in this thesis lies on the transports through the Strait of Dover. Studies on fluxes through the Strait of Dover date back to the late 1920’s, where in situ velocity profiles were measured and integrated over the crosssection to make an estimate on residual flows. In later studies different methods were used to obtain valuable information on transports. Use was made of electric potentials through a telephone cable, high frequency radars and modelling studies. Because the magnitude of residual transports is an order of magnitude smaller than short scale movements like tidal oscillations, the estimated trans- ports lack accuracy. They vary between 87000 to 235000 m3/s. Dutch ecologists suggests an annual inflow in the order of 100000 m3/s. In this thesis the state-of-the-art numerical DCSM models of Deltares have been com- puted in Delft3D-FLOW to investigate the dominant processes in the Strait of Dover. The models cover the complete northwest European continental shelf and calculate depth aver- aged barotropic flow. The representation of the general North Sea circulation is qualitatively well, except for some highly stratified and density driven areas. However, the in- and outflow of water at the North Sea boundaries is considerably low. The leakage of the radioactive nuclide Antimony-125 from La Hague in 1985 till 1994 has been simulated to give an in- dication of the spatial varying transit time of the current model. It is shown that in the southern region transit times are simulated to be two times larger than other modelling studies and measurements suggest. The daily varying residual flow through the Strait of Dover has been investigated by applying a Low-Pass frequency filter to the modelled fluxes. The contribution of tidal residuals are found to be very significant with an average annual flow of 45000 m3/s. When meteorological forcings are also taken into account the annual inflow for the year of 2007 equals 56000 m3/s. Since meteorological forcings vary throughout the years, a quasi-linear approximation is formulated where the daily residual flow is a function of the wind induced shear stress and wind direction. A correlation of 0.79 is found for this linear approximation. For rapidly varying surface elevations differences between the North Sea and English Channel the approximation fails to give proper estimates. During the research, model adjustments were made to (1) assess the sensitivity of the fluxes and (2) look for candidate solutions to improve the amount of transport through the Strait of Dover. Physical adjustments have been made by implementing density differences, residual surface level boundaries and a varying bottom roughness. The numerical adjust- ments were for the largest part based on different discretization methods. In addition, a preliminary computation has been performed in DFlow-FM; a recently developed simulation package which computes on an unstructured grid. Although there are notable differences for each adjustment, the effects are small in comparison with tide and wind induced residuals.","Residual flow; Strait of Dover; North Sea; Residual circulation","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:058fd6c0-3df9-49ea-87ff-9004396f99dd","http://resolver.tudelft.nl/uuid:058fd6c0-3df9-49ea-87ff-9004396f99dd","Low Cycle Corrosion Fatigue in the North Sea Environment","Anijs, M.A.","Bijlaard, F.S.K. (mentor); Kolstein, M.H. (mentor)","2013","Low cycle corrosion fatigue is an interesting issue in civil Engineering because it may effect the lifetime of structures in negative and unexpected ways. However, analysis of design codes has revealed that low cycle corrosion fatigue is not a major issue in the design of offshore structures because these structures are designed with a global elastic philosophy. This means that the number of cycles that a structure can withstand usually stays well within the high cycle range. The joints ( welded or otherwise ) revealed to be the less resistant elements to low cycle corrosion fatigue. Furthermore, it was revealed that in the ultra low cycle region the effect of the environment is heavily reduced. It was also revealed that the effect of cathodic protection is strongest in the upper spectrum of the high cycle range and deteriorates in the lower spectrum of the high cycle range. It was also revealed that a structure in air and a structure in seawater with cathodic protection have essentially the same fatigue resistance when in the ultra low cycle range. In the ultra low cycle range, the problem appears to turns into mostly a low cycle fatigue problem. In the ultra high cycle region the problem appears to turns into mostly a corrosion problem. S-N curves that can predict the low cycle fatigue life of structures in a deleterious environment are very rare. The only S-N curve available that can be used for structural steel subjected to low cycle corrosion fatigue is one for tubular sections. However, Mathematical modeling based on regression and a principle of constant slopes in a fatigue cycle region ( low cycle, high cycle, ultra high cycle ) has made it possible to not only calculate the low cycle corrosion fatigue life of tubular joints but the low cycle corrosion fatigue life of other types of joints as well.","Fatigue; Low Cycle; Environmental Cracking; Low Cycle Fatigue; Low Cycle Corrosion Fatigue; North Sea","en","master thesis","","","","","","","","2013-11-08","Civil Engineering and Geosciences","Structural Engineering","","Structural and Building Engineering","",""
"uuid:415380de-0cd9-4e6d-aeb6-e1c8f6f5667c","http://resolver.tudelft.nl/uuid:415380de-0cd9-4e6d-aeb6-e1c8f6f5667c","Determining changes in CO2 saturation from time-lapse measurements using ghost reflections retrieved by seismic interferometry","Draganov, D.S.; Ghose, R.; Angelov, P.; Arts, R.","","2013","One of the targets of time-lapse seismic monitoring of CO2 sequestration is to determine the parts of the reservoir reached by the injected CO2 and to estimate their saturation. Such information could be extracted from the time-lapse measurement using AVO or impedance information. But non-repeatability of the source positions and time-lapse changes in the overburden could lower the accuracy of the estimation of saturation. We propose the utilization of non-physical (ghost) reflections retrieved by seismic interferometry to estimate the CO2 saturation inside the reservoir. We use the ghost reflections to directly estimate the layer specific velocities inside the reservoir and the cap rock and thus eliminate the two mentioned causes of inaccuracies. We apply this idea and demonstrate its added value and potential using numerically modelled data for a simplified model based on the Sleipner underground storage site in the North Sea.","correlation; monitoring; time-lapse; North Sea; saturation","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:68e4e599-51ab-40df-8fb4-918f5f54a453","http://resolver.tudelft.nl/uuid:68e4e599-51ab-40df-8fb4-918f5f54a453","Roadmap to a mutually consistent set of offshore vertical reference frames","Slobbe, D.C.","Klees, R. (promotor)","2013","This thesis presents a combined approach for the realization of the (quasi-)geoid as a height reference surface and the vertical reference surface at sea (chart datum). This approach, specifically designed for shallow seas and coastal waters, provides the relation between the two vertical reference surfaces without gaps down to the coast. It uses a shallow water hydrodynamic model which provides water levels relative to a given (quasi-)geoid. The latter requires that the hydrodynamic model is vertically referenced to the same (quasi-)geoid. Vice versa, the hydrodynamic model is also used to realize a (quasi-)geoid by providing corrections to the dynamic sea surface topography, which are used to reduce radar altimeter-derived sea surface heights to the (quasi-)geoid. The coupled problem of vertically referencing the hydrodynamic model and computing the (quasi-)geoid is solved iteratively. After convergence of the iteration process, the vertically referenced hydrodynamic model is used to realize the chart datum. In this way, consistency between the chart datum and (quasi-)geoid is ensured. The feasibility and performance of this approach is demonstrated for the Dutch North Sea and mainland. It is shown that the differences between modeled and observed instantaneous and mean dynamic sea surface topography is 8-10 cm and 5.8 cm, respectively, for the Dutch North Sea. On land, it is shown that the methodology provides a (quasi-)geoid which has a lower standard deviation than the European Gravimetric Geoid 2008 (EGG08) and the official Netherlands (quasi-)geoid NLGEO2004-grav when compared to GPS-levelling data. The standard deviation at 81 GPS-levelling points is below 1 cm; no correction surface is needed. Finally, it is shown that the chart datum (lowest astronomical tide, LAT) agrees with the observed chart datum at 92 onshore tide gauges to within 21.5 cm standard deviation. This study also examines the impact of instantaneous dynamic sea surface topography (DT) corrections to be applied to altimeter-derived sea surface slopes on the quasi-geoid in the shallow and coastal waters of the North Sea. It is found that the steric and surge parts of the DT mainly contribute to improvements in the signal-to-noise ration at longer wavelengths down to 100-200 km and that the improvements increase towards the southern North Sea. It is also found that the shallow water hydrodynamic model provides better tidal corrections compared to a global ocean tide model, which are most pronounced in the southern North Sea and affect almost the entire spectrum. In terms of quasi-geoid heights, the differences are very small differences (mostly below ±2 cm). This is explained by the fact that altimeter-derived (quasi-)geoid slopes hardly contribute to the estimated quasi-geoid if shipboard gravity data are included. The last question treated in this thesis is whether a spherical Slepian basis representation enables to obtain spectral consistency between a high- and low-resolution data set (following recent studies, this question is treated in the context of mean dynamic topography (MDT) estimation by computing the difference between a high-resolution mean sea level (MSL) model obtained from satellite altimetry and a low-resolution gravimetric geoid). The answer is no; a Slepian representation of the low-resolution MSL signal suffers from broadband leakage. Furthermore, it is shown that a meaningful definition of a low-resolution MSL over incomplete spherical domains involves orthogonal basis functions with additional properties that Slepian functions do not possess. One of these sets of orthogonal basis functions are computed using the Gram-Schmidt orthogonalization for spherical harmonics. For the oceans, an orthogonal basis could be constructed only for resolutions equivalent to a spherical harmonic degree 36. The computation of a basis with a higher resolution failed due to inherent instabilities. More research is needed to solve the instability problem.","vertical reference surfaces; quasi-geoid; lowest astronomical tide; hydrodynamic model; radar altimetry; dynamic sea surface topography; slepian basis; spectral consistency; mean dynamic topography; vertical referencing; geoid; chart datum; North Sea; ellipsoidally referenced surveying","en","doctoral thesis","","","","","","","","2013-09-06","Civil Engineering and Geosciences","Geoscience and Remote Sensing","","","",""
"uuid:ebbe88d3-effa-45d2-a9a6-716b95614ef3","http://resolver.tudelft.nl/uuid:ebbe88d3-effa-45d2-a9a6-716b95614ef3","An Improved Method for the Monitoring of the Productivity of Natural Gas Wells","Vesters, J.B.","Zitha, P.L.J. (mentor); Blandamour, H. (mentor)","2013","Up to now the well performance department within Total Exploration and Production Netherlands (TEPNL) base the assessment of well inflow performance on experiences in the field. No tools are available to systematically monitor and assess the reservoir-completion-tubing performance in the longer term (years). This makes that normal production decline cannot be discriminated from abnormal production decline and productivity decline over long periods of time cannot be observed. The well management process is complicated by the large number of small reservoirs operating in different circumstances. As a result well performance interventions have largely become a remedial activity rather than a pro-active way of increasing production. In this thesis we will discuss the development of two tools that will allow the performance engineers to monitor all 52 TEPNL productivities over the entire period of time digital production data is available. Problematic wells are selected based on their initial productivity and their current productivity. Productivities are determined using Forchheimers correlation. Tagged well are coupled to an appropriate analytical skin model, depending on the well configuration. Evolution of certain parameters that are identified as being impactful on the PI of the specific are calculated. Certain mechanisms have been proposed which cause well performance deterioration. The root cause for the decline is interpreted based on well historics, surface measurements of salinity and the evolution of PI. Finally, when a cause has been established and it appears to be skin related an intervention can be proposed and potential production gains can be estimated. The new tools can also be used to review past interventions in a systematic and simple manner. At this moment well interventions are not or hardly reviewed on their impact. The tool can now help to quantify the problem, as well as give an objective measure of the success of past interventions. The approach proposed in this thesis is new, and only limited data is available to validate the approach. Some promising results are observed based on the 4 interventions done in the past as well as well historics currently available. At this stage, the method tags an additional 9 wells as declining faster as expected. 4 of which are suspected to be related to skin buildup, 1 to water invasion, 1 to interference with another well and 1 due to tubing damage. The remaining 2 wells could not be linked to a single specific cause, 1 well is either suffering from salt deposition or water advancement, while the other either salt deposition or tubing damage.","productivity; gas wells; North Sea; well decline","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","Petroleum Engineering","",""
"uuid:ba51915d-048e-42a5-a004-8022f82ca83a","http://resolver.tudelft.nl/uuid:ba51915d-048e-42a5-a004-8022f82ca83a","Improving the Algal Bloom Prediction in the North Sea by Ensemble Kalman Filtering in the GEM/BLOOM Model","Rens, E.G.","El Serafy, G.Y.H. (mentor); Heemink, A.W. (mentor)","2013","The ecological state of the North Sea surface water can be indicated by ocean variables such as the Chlorophyll-a (Chlfa) concentration. Chlfa is the principal photosynthetic pigment and is common to all phytoplankton and can therefore be used as a measure of phytoplankton biomass. The GEM/BLOOM model developed at Deltares is a generic ecological model that simulates transport of substances in a water system along with various ecological processes. This model is able to estimate the Chlfa concentration. Models are always prone to errors due to assumptions made in the development and the use of numerical approximations. Such errors can be reduced through the use of data assimilation and thus can significantly improve the forecast. The ensemble Kalman filter (EnKF) is a generic data assimilation method which is suited for highly nonlinear models with a large scale. This filter is validated by the use of twin experiments on the GEM/BLOOM model. It successfully improves the prediction of Chlfa,but however shows filter divergence in some grid points. The performance is further improved by the use of the Ensemble Square Root Filter (ESRF) with a localized analysis. Finally, application of this filter to assimilating daily MERIS remote sensing images is explored and shows to be promising, but requires more tuning before it can operate.","data assimilation; ecological modeling; remote sensing images; ensemble kalman filter; ensemble square root filter; covariance localization; chlorophyll-a concentration; algal blooms; phytoplankton; north sea","en","master thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Applied Mathematics","","Mathematical Physics","",""
"uuid:b2ce15c3-8b44-4f8c-8902-fdbbcacea55a","http://resolver.tudelft.nl/uuid:b2ce15c3-8b44-4f8c-8902-fdbbcacea55a","Developing a parametric model for storms to determine the extreme surge level at the Dutch coast","De Jong, M.S.","Vrijling, J.K. (mentor); Van Gelder, P.H.A.J.M. (mentor); Holthuijsen, L.H. (mentor); Van Ledden, M. (mentor); Den Heijer, C. (mentor)","2012","To date no study has been done to analyse the effect on water level for the Dutch coast from the passage of storms over the North Sea. This research examines the feasibility of developing a joint probability method to determine the extreme water level for the Dutch coast, resulting from these storms. This has been done by means of a parametric model, which determines the hydraulic boundary conditions from a set of significant storm parameters. The objective of this research is to obtain physical knowledge in predicting the water level for the Dutch coast. This provides a better understanding of the contribution of storm characteristics to high water levels, and can therefore be very useful in the forecasting of extreme surges from the passage of these storms. Secondly, possible changes in meteorology can be taken into account in this model, in contrast to the current method. Another advantage is that the simulated wind field based on storm parameters may also be a tool for simulating and understanding the behaviour of waves for the North Sea and the joint probability with the water level.","Storms; North Sea; extreme statistics; wind; probability distribution; ocean surface; storm characteristics","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:aca1543e-7fff-47ed-b4b7-371c5acb54f1","http://resolver.tudelft.nl/uuid:aca1543e-7fff-47ed-b4b7-371c5acb54f1","Update Offshore Wind Atlas: Implementing a variable sea surface roughness","Donkers, Jeroen (TU Delft Aerospace Engineering)","Bijl, Hester (mentor); Brand, A.J. (mentor); Delft University of Technology (degree granting institution)","2010","In 2005 the Energy research Centre of the Netherlands (ECN) published its first version of the Offshore Wind Atlas of the Dutch part of the North Sea [3]. This version has been updated and improved using longer time series and another approach for the calculation of the roughness of the sea surface. In contradiction to other Wind Atlases which are based on measurements [28], use is made of data from the Numerical Weather Prediction model Hirlam. Measurements of wind speeds and directions are only used to validate the Wind Atlas. For the Offshore Wind Atlas, the Hirlam data is interpolated where for the vertically interpolation use is made of the Businger-Dyer profiles in combination with the Monin-Obukhov length [3]. One of the required parameters for the interpolation is the surface roughness. For land, it can be assumed constant while for sea it is variable. In the previous version of the Offshore Wind Atlas, the sea surface roughness has been determined using Charnock’s relation [9], where the so-called Charnock parameter is constant. In the new version, the equation of Hsu is introduced which states that the Charnock parameter is variable and dependent on the wave steepness i.e. the wave height divided by the wave length [19]. Assuming that the North Sea is a shallow sea and using the general wave equation, which relates the sea depth and wave length to the phase velocity of the waves, it was found that the wave steepness can be rewritten in a fraction of the wave height over the wave period multiplied by the square root of the sea depth times the gravitational acceleration. These quantities are derived from measured values which are interpolated to the location of interest. Using this approach, it is tried to improve the prediction of the wind speed distributions for a given location and altitude. Using wind measurements at several locations it was found that adding the wave data to the computations show a small improvement in the estimation of the wind speed distribution compared to the previous version of the Offshore Wind Atlas. For each measurement location and method, a two parameter Weibull distribution has been made, after which a comparison was done between the various shape and scale parameters. Generally, the scale parameter was overestimated by both versions of the Offshore Wind Atlas compared to the measurements. The cause of this behavior might be found in the data used to make the Atlas. The shape parameter is well predicted by the new version of the Offshore Wind Atlas due to the use of wave data. The influence of the wave data is found to be larger for lower altitudes than for higher altitudes. Besides Weibull distributions, also maps with average wind speeds are given by the Offshore Wind Atlas which are compared to older maps.","Wind Atlas; North Sea; Offshore; Sea Surface Roughness","en","master thesis","","","","","","","","","","","","Aerospace Engineering","",""
"uuid:0c8b093c-2d86-45e6-8fc4-710782b63831","http://resolver.tudelft.nl/uuid:0c8b093c-2d86-45e6-8fc4-710782b63831","Process-based and Surrogate Modelling of Fine Sediment Transport in the Dutch Coastal Zone","Kai, C.","","2009","Coastal zones which are known as the interface between continents and oceans are vital and important to human beings because a majority of the world's population live in such zones (Nelson, 2007). Coastal systems are among the most dynamic and energetic environments on earth and they are continuously changing because of the dynamic interaction between the oceans and the land. Dronkers (2005) described coasts as multiform, infinitely complex, quasi-fractal, always changing and unpredictable. Sediment process, especially fine sediment transportation is a very complicated feature in many coastal zones as it is affected by physical dynamics, tide, wave, wind and their mutual interactions. Waves and winds along the coast are both eroding rocks and depositing sediments continuously, and the rates of erosion and deposition vary considerably from day to day. Tidal currents also have great effects on sediment transportation. Sedimentation causes many problems in coastal systems. Fine suspended sediment affects local morphology in coastal rivers, estuaries and shelves environments. Fluid mud, a high concentration aqueous suspension of fine sediment, impedes navigation, reduces water quality and causes environmental damages (Sowed, 2008). So it is crucial and of great interests for coastal engineers and water managing authorities to improve understanding of the underlying sedimentation processes and then further to carry out plans for water management, coastal protection, channel maintenance, land reclamation and dredging of deepwater navigational channels, etc. Along the Dutch Coast, a lot of efforts have been made to improve the prediction and understanding of sediment transport processes. Process-based models such as SOBEK and Delft3D of Deltares have been proved to be useful in simulation of 2D/3D sediment processes in the Dutch coastal areas. Delft3D solves shallow water equations and transport equations for salinity and suspended particulate matter (SPM) numerically by using a finite-difference scheme. Delft3D was used to build both large-scale and small-scale models to predict SPM concentrations and siltation rates in the Dutch coastal zones. For example, Van Kessel et al. (2007) built model of the Southern North Sea and Li (2007) built a local model focused on the mouth of River Rhine. The results from both models were satisfactory. However, simulating sediment transportations with process-based models is often quite time consuming, which restricts process-based model for widely applications. More detailed information will be introduced in Chapter 1.3. Data-driven models (DDM) have also been used in simulation of sediment processes (Bhattacharya et al., 2006). They are based on limited knowledge of physical processes and rely on the data describing input and output characteristics. Data driven techniques are used in building models to solve mathematical equations from the analysis of concurrent input and output time series instead of the analysis of physical processes. Solomatine and Ostfeld (2008) described that the model works on the basis of connections between the system state variables (input, internal and output variables) without considering too much on assumptions about the natural processes of the system.","Dutch coast; North sea; wadden sea; coastal sediment; currents; morphology; sedimentation processes; process based models; SOBEK; Delft3D; shallow water; suspended particulate matter; SPM; river Rhine; data driven models; DDM; morphological; meteorological; hybrid modelling; Delft Cluster; CT05.20; Noordzee & kust; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:c5c07865-be69-4db2-91e6-f675411a4136","http://resolver.tudelft.nl/uuid:c5c07865-be69-4db2-91e6-f675411a4136","On the interaction between tides and stratification in the Rhine Region of Freshwater Influence","De Boer, G.J.","Stelling, G.S. (promotor); Pietrzak, J.D. (promotor)","2009","","southern north sea; semi-diurnal tides; advection and strain induced periodic stratification; rofi; river plume; baroclinic numerical model delft3d; coastal upwelling; tidal straining; tidal ellipses; knmi noaa sst satellite imagery; potential energy anomaly equation","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:1910856a-7f2b-410a-82cd-9a46537231bb","http://resolver.tudelft.nl/uuid:1910856a-7f2b-410a-82cd-9a46537231bb","Large scale physical model tests on the stability of geocontainers","Van Steeg, P.; Klein Breteler, M.","","2008","Within the framework of the workpackage 4c: “Flexible coastal defence with geosystems”, which is part of the workpackage 4: “Morfodynamics of the North Sea and coast” several problems are formulated with respect to the application and design of Geosystems. This is performed within the Delft Cluster project “Sustainable development of North sea and coastal zone”. The formulated problems are: 1. Stability of geocontainers under wave attack and/ or currents. 2. Positioning accuracy of geocontainers. 3. Required strength of the geotextile during the placement of geocontainers. 4. Sustainability of geocontainers with respect to UV load, ageing process and mechanical loads. The first subject is suitable for research in Delft Cluster 2. Taking in mind that wave loads are a larger problem with respect to the stability than currents, the former is selected for research. The second and third topic have been investigated in Delft Cluster 1. This resulted in an improvement of knowledge. The main goal in the long run, providing a thorough insight in the risks of applying geocontainers, can be realised by backing up the research with practical experience and scale model tests. The costs of these are however too much to include in Delft Cluster 2. UV loads and ageing processes of geotextile are subjects in the domain of the manufacturers of geotextiles. Therefore, it is decided, in close cooperation with the Centre for Civile Engineering Research and Codes (CUR), to focus on the stability of geocontainers under wave attack. This report describes and analyses the large scale model tests which have been executed to determine the stability of geocontainers.","physical model tests; geocontainers; coastal defence; geosystems; morfodynamics; North Sea; coast; wave attack; currents; geotextile; sustainability; scale model tests; Delft Cluster; CT05.20; Noordzee & kust; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:fcb49e4d-b0e0-45a4-9d67-be7ec4430ffd","http://resolver.tudelft.nl/uuid:fcb49e4d-b0e0-45a4-9d67-be7ec4430ffd","A Hybrid Approach to Combine Physically Based and Data-Driven Models in Simulating Sediment Transportation","Sewagudde, S.","","2008","The objective of this study is to develop a methodology for hybrid modelling of sedimentation in a coastal basin or large shallow lake where physically based and data driven approaches are combined. This research was broken down into three blocks. The first block explores the possibility of approximating a physically based model using a data driven model to predict suspended particulate matter (SPM) concentrations. It identifies the necessary input variables and data manipulation operations to expose maximum information to a data driven modelling tool. The second block investigates the effect of specifying time varying open boundary condition instead of fixed boundary conditions on the simulation of (SPM) along the Dutch coast. First, a methodology for generating time varying open boundary conditions using a data driven model is developed. Local hydrodynamic and meteorological conditions are used as input variables. Secondly the improvement of the time varying open boundary conditions (OBC) on the simulation results is studied The third block examines how knowledge gained in modelling sediment transport along the Dutch coast can be transfer to understand sediment transport in Lake Victoria. This part lays ground for more accurate and reliable modelling of sediment transport in Lake Victoria in future through transfer of methods developed in the preceding sections.","hybrid approach; physically based; data driven; simulating sediment transportation; hybrid modelling; sedimentation; coastal basin; shallow lake; model; suspended particulate matter; SPM; simulation; Dutch coast; hydrodynamic; meteorological; open boundary conditions; OBC; sediment transport; Lake Victoria; North sea; Delft Cluster; CT05.20; Noordzee & kust; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:8ec40dbe-306f-4e6b-91fe-c078693c7d24","http://resolver.tudelft.nl/uuid:8ec40dbe-306f-4e6b-91fe-c078693c7d24","Modelling the seasonal dynamics of SPM with a simple algorithm for the buffering of fines in a sandy seabed","Van Kessel, T.; Winterwerp, H.; Van Prooijen, B.; Van Ledden, M.; Borst, W.","","2007","This paper discusses the application of a simple algorithm for the buffering of fines in a sandy seabed. A second layer is introduced in which fines may be stored during calm weather and from which fines may be resuspended during storms. The algorithm is applied first in a one-dimensional vertical (1DV) point model at a location in the North Sea, Noordwijk 10, 10 km offshore. It is able to reproduce the observed temporal variability of suspended particulate matter satisfactorily. Apart from the second layer, also the applied first order erosion rate is an important element of the algorithm. This allows for an equilibrium sediment mass per unit area for any combination of bed shear stress climate and sediment supply. The classical Partheniades-Krone formulation with zeroth order erosion (i.e. an erosion rate that is independent from the sediment mass per unit area) does not have such equilibrium. As a next step, the algorithm is incorporated into a 3D model for suspended particulate matter (SPM) transport in the Dutch coastal zone. It is demonstrated that the model is able to reproduce the observed spatial and temporal variability reasonably well. An essential feature of the 3D mud model is that it is sufficiently fast to compute equilibrium bed composition. This implies that the results are completely independent from the applied (uniform) initial conditions. Finally, the mud model is applied to assess the impact of a large-scale release of fines in the Dutch coastal zone. The computed impact turns out to be very sensitive to the assumed buffer capacity of the seabed. However, information on transient system response (such as the dissipation of a sediment pulse in the system) from which the buffer capacity may be estimated is most often lacking. For the time being, estimates on the residence time of fines in the seabed and its mixing depth are derived from the literature. Additional field and laboratory test on the exchange mechanisms of fines between the water column and a sandy seabed are recommended.","suspended sediment; 3D model; seasonal dynamics; North Sea; bed algorithm; CT05.20; Noordzee & Kust; CT05.24.11; Morfodynamiek van Noordzee; Delft Cluster; SPM; seabed","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:6fd979a8-b6de-457a-b23f-d6a952e70e4f","http://resolver.tudelft.nl/uuid:6fd979a8-b6de-457a-b23f-d6a952e70e4f","Fluxes of fine sediment along the Dutch coast and the impact of Maasvlakte 2: A system description","Winterwerp, J.C.","","2006","","monitoring; monitoring; silt; silt; Maasvlakte; zwevend transport; suspended load transport; North Sea","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:ae0d95bd-2958-4efd-9a5d-22fd97d7d7ee","http://resolver.tudelft.nl/uuid:ae0d95bd-2958-4efd-9a5d-22fd97d7d7ee","Equilibrium and stability of a double inlet system","Brouwer, R.L.","Stive, M.J.F. (mentor); van de Kreeke, J. (mentor); Zitman, T.J. (mentor); Schuttelaars, H.M. (mentor); Wang, Z.B. (mentor)","2006","Barrier island coasts are a common feature in many parts of the world. An example is the Wadden coast of The Netherlands, Germany and Denmark. These coasts consist of barrier islands separated by tidal inlets with at the landward side tidal basins.Characteristic for the Wadden Sea is that the tidal basins are not completely separated,but are connected via topographic highs allowing exchange of water between the basins. As a result the tidal inlets that connect the basins to the North Sea will interact. The focus in this thesis is on the effect of this interaction on the cross-sectional equilibrium and stability of tidal inlets that are part of a double inlet system. The knowledge gained in this study will help to develop rational management plans for this kind of system. In determining the equilibrium values and stability of cross-sectional areas of the inlets use is made of flow diagrams. A flow diagram consists of the equilibrium flow curves of each inlet and a flow field showing the adaptation of the inlet cross-sections after the system has been removed from equilibrium. Each intersection of the equilibrium flow curves represents a stable or unstable equilibrium. The equilibrium flow curve for each inlet is the locus of the values of the cross-sectional areas for which the velocity amplitude in the inlet equals the equilibrium velocity i.e. approximately 1 m/s according to ESCOFFIER [1940]. As a start the double inlet system is schematized as a basin connected to the ocean by two channels. The water surface area of the basin is assumed constant and water levels are assumed to fluctuate uniformly. On the seaward side a simple harmonic, semidiurnal tide is used to force the system. Analyzing the double inlet system under these conditions by means of the flow diagrams leads to the conclusion that a stable equilibrium of the two inlets does not exist. Ultimately only one inlet remains open and the other will close. This confirms the earlier conclusions of VAN DE KREEKE [1990] and BORSJE [2003] concerning the cross-sectional stability of multiple inlet systems.","Delft Cluster; CT05.20; Noordzee & kust; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging; barrier island coasts; wadden coast; tidal inlets; North Sea; double inlet system; flow diagram; van de Kreeke; Borsje; hydrodynamics","en","master thesis","TU Delft; Faculty of Civil Engineering and Geosciences, section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:5f288104-e707-4606-900a-ecec7c3c1373","http://resolver.tudelft.nl/uuid:5f288104-e707-4606-900a-ecec7c3c1373","Modelling of Cohesive Sediment Transportation, Deposition and Resuspension in the Haringvliet Mouth.","Qinghua, Y.","","2006","In the Dutch coastal zone, where the marine environment is characterized by shallow depths and highly energetic hydrodynamic conditions, the cohesive sediments, or mud, play an important role in the local morphology. For instance, mud deposits and high concentrations of suspended particulate matter (SPM) occur frequently, especially during extreme wave conditions, which lead to a great concern to transportation authorities and coastal managers. Several researchers contributed to the understanding of the cohesive sediment dynamics in the Dutch coastal zone. Nevertheless, the mechanism of cohesive sediment transportation, deposition and resuspension, especially due to wave effects, needs further studies and careful formulation. The main objective of this study is to increase the understanding of the complex patterns of cohesive sediments transportation, deposition and resuspension due to wave effects with tide, wind, density-driven flow in the Dutch coastal area. The study focuses on the areas adjacent to the approach channel of the port of Rotterdam and Haringvliet Mouth, which are characterized by complex interactions between hydrodynamics and sedimentation. Based on the scale linkage theory of de Vriend and rules of Roelvink to keep models simple, the study is carried out with three models at different spatial and temporal scale. Firstly, the study starts with the extension of the existing ZUNO model of the North Sea in a macro spatial scale using Delft3D FLOW and WAVE modules. The sediment movements under wave dynamics are verified as well. Secondly, the domain decomposition technology to generate locally refined grid to cover the studied area. Simulations are carried out with flow, wave, sediments, and morphology modules of Delft3D. Thirdly, the simulated results with the ZUNO coarse grid model is utilised as the boundary condition of another fine grid model of the Haringvliet Mouth. This model is set up to study the influence of waves upon the cohesive sediments in the Haringvliet Mouth in a meso-temporal and spatial scale. The specific boundary conditions of the model are introduced intentionally with harmonic tidal forcing and real time discharge from the Haringvliet Sluice. After the calibration of the wave model and cohesive sediment transportation model, the coupled models show the correct pattern of the cohesive sediment distribution in the area. It reproduces successfully the cohesive sediment transportation, deposition and resuspension pattern mainly due to wave effects in the areas adjacent to the approach channel of the port of Rotterdam and Haringvliet Mouth, which has been verified by measured sediments data. The model results show that the wave dynamics is one of the most significant processes behind the sediment movements in the Haringvliet Mouth.","modelling; cohesive sediment transportation; deposition; resuspension; Haringvliet Mouth; Dutch coastal zone; hydrodynamic; cohesive sediments; morphology; SPM; suspended particulate matter; port of Rotterdam; sedimentation; de Vriend; rules of Roelvink; models; ZUNO; Delft3D; North Sea; flow; wave; Haringvliet Sluice; Delft Cluster; CT05.20; duurzame ontwikkeling Noordzee en kustzone; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:5bfe26e3-f3cd-4445-afe9-159e6b8beff3","http://resolver.tudelft.nl/uuid:5bfe26e3-f3cd-4445-afe9-159e6b8beff3","Constraints from ice dynamics for ice load histories from GIA data of the last ice age, and evidence from GIA data for glaciation of the North Sea Basin","Van den Broek, M.","Vermeersen, L.L.A. (mentor); Schotman, H.H.A (mentor)","2006","","glacial isostatic adjustment; ice dynamics; north sea basin","en","master thesis","TU Delft, Aerospace Engineering, Astrodynamics and Satellite Systems","","","","","","","","Aerospace Engineering","","","","",""
"uuid:f8be468f-4892-4acd-905a-d986c9da3096","http://resolver.tudelft.nl/uuid:f8be468f-4892-4acd-905a-d986c9da3096","Measurement report tidal inlet Ameland for the storm season 2004-2005","Gautier, C.; Van den Boomgaard, M.J.G.","Ruijter, M.N. (contributor); TU Delft","2005","This report contains the analysis of the measurements by ten wave buoys near the tidal inlet of Ameland during the storm season 2004-2005 (1 December 2004 - 1 May 2005).","tidal inlet; wave measurement; North Sea; Ameland; dikes; buoy","en","report","Svasek","","","","","","","","","","","","",""
"uuid:49f188fb-fade-48b2-b0ec-bdc26caae3cf","http://resolver.tudelft.nl/uuid:49f188fb-fade-48b2-b0ec-bdc26caae3cf","Remote sensing of the river Rhine plume","Arentz, L.","Pietrzak, J.D. (mentor); De Boer, G.J. (mentor); Tatman, S. (mentor); Winterwerp, J.C. (mentor); Roelvink, J.A. (mentor); Stelling, G.S. (mentor)","2004","The data content of remote sensing (RS) images of sea surface temperature (SST) and normalized water-leaving radiance (nLw), for the year 1998, with respect to the River Rhine plume, is investigated. Questions that this study tries to answer are: is it possible to identify the plume from the available RS images, and under which conditions is this possible? How much information on the plumes behaviour can be derived from these images? Does or can this information contribute to our general knowledge of the plume? The images provide a spatial resolution of I km2 and a temporal resolution of I or 2 images per day per sensor for nLw and SST, respectively (in the case of a cloudless atmosphere). In the presence of clouds, no signal is detected for the area of surface water underneath the clouds. Two hypotheses are set up to explain how the RS images can be used to trace the plume. In the hypotheses links are established between salinity gradients that delimit the plume and SST and nLw respectively. The results are based on these hypotheses. From the available images, 9 SST images in spring provide detailed information on the stratified plume and allow for derivation of indirect information on sub-surface processes. In winter the temperature gradients as visible on SST imagery seem to indicate the broad plume patterns. From the nLw images it was not possible to identify the boundaries of the plume. However it is expected that the nLw images are an excellent source for monitoring suspended particulate matter (SPM) in the North Sea. The general conclusion of this study is that the RS data used in this project provide a valuable source of information, with respect to the Dutch coastal zone, in addition to the currently available measurement techniques and computer models. The SST imagery turns out to be particularly useful for tracing stratification, whereas nLw imagery seems to be an excellent source for monitoring SPM in the North Sea. For detailed monitoring of the DCZ and the plume, increased spatial and temporal resolutions are required.","pollution; plume; Rhine river; North Sea","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:af202f38-7574-4913-9036-ab5b12496ff0","http://resolver.tudelft.nl/uuid:af202f38-7574-4913-9036-ab5b12496ff0","Atlas of near-surface Total Suspended Matter concentrations in the Dutch coastal zone of the North Sea","Suijlen, J.M.; Duin, R.N.M.","Rijkswaterstaat","2002","Suspended matter in the water column governs the under water light climate and is thus an important factor for life in the sea. Next to nutrients, light is essential for the growth of phytoplankton and in this way for the food chain in the sea. Suspended matter concentrations are highly variable in time and space. Thus it is very hard to assess the influence on these concentration levels of any anthropogenic acting. Furthermore, the relations between suspended matter and the food chain are very complicated. These two facts hamper a fair estimate of the effects on the ecosystem of foreseeable anthropogenic measures that may infer changes in suspended matter transports. As a prerequisite for managing a sustainable use of the North Sea, basic information on the highly variable suspended matter concentrations in the marine environment is therefore needed. Through charts and graphs, this atlas gives an insight in the nearsurface suspended matter concentrations and their variability in the Dutch coastal zone (ca. 70 km wide). The charts of the near-surface suspended matter concentrations are based on the DONAR data of the monitoring WAKWON programme carried out between 1975 and 1983. The variability in space and time is further elucidated by dedicated graphs and charts. As a result of research (Suijlen and Duin, 2001) the suspended matter concentrations appear to be mainly determined by the wave heights. This results in high concentrations during the stormy winter periods and low concentrations during calm summer periods. Besides a seasonal variability, a long-term variability exists with periods of 4-8 years. Taking into account the variability in the concentration levels, it is estimated that the net northward transport of suspended matter in the coastal zone (ca. 70 km wide) ranges between about 6 and 60 Mton per year. This transport depends on the waves during that year, as well as on the flux of sediments from the English Channel and the Flemish banks. Although based on data measured between 1975 and 1983, the charts and graphs presented in this atlas are representative for the present suspended matter concentrations.","suspended; underwater climate; ecology; phytoplankton; light climate; North Sea; suspended matter","en","report","Rijkswaterstaat, RIKZ","","","","","","","","","","","","",""
"uuid:50d5ec50-9146-4d01-8eb9-14e0fae44f64","http://resolver.tudelft.nl/uuid:50d5ec50-9146-4d01-8eb9-14e0fae44f64","3D modelling for the Southern North Sea","Goede, E.D. de","","2001","","North Sea; dichtheid; density; hydrodynamica; hydrodynamics; driedimensionale modellen; three-dimensional models","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:ec7e0408-7bc9-4dd3-8499-7261f18f352e","http://resolver.tudelft.nl/uuid:ec7e0408-7bc9-4dd3-8499-7261f18f352e","Schiphol in zee: Golfdiffractie om het eiland","Van Hoof, J.G.G.","Van de Graaff, J. (mentor); Booij, N. (mentor); D' Angremond, K. (mentor)","2001","In deze studie is de invloed van golfdiffractie onderzocht op het golfveld achter een eiland in de Noordzee op 10 km uit de kust. Dit onderzoek is uitgevoerd als afstudeeropdracht voor de studie Civiele Techniek aan de Technische Universiteit Delft. Het aanleggen van een eiland voor de Nederlandse kust heeft consequenties voor deze kust. Door de aanleg van het eiland veranderen de golfcondities tussen het eiland en de kust. De gewijzigde golfcondities veroorzaken morfologische veranderingen van de kust en de zeebodem. De ontwikkeling van de kust kan voorspeld worden met kustmorfologische modellen. Deze modellen bevatten een golfmoduul voor de bepaling van het golfveld. Diffractie wordt in de gangbare golfmodulen niet meegenomen. In deze studie wordt onderzocht wat de invloed van de golfdiffractie om het eiland is op het golfveld tussen het eiland en de kust. Door het uitvoeren van numerieke berekeningen wordt het effect van golfdiffractie op het golfveld tussen het eiland en de kust bepaald. Hiervoor zijn het refractie-diffractiemodel GREON en het refractie-model HISWA gebruikt. Om de realiteitswaarde van het model GREON te toetsen, is dit model vergeleken met de Spiraal van Cornu die bekend staat als een betrouwbare analytische methode. Daarnaast wordt onderzocht of in een refractie-model de diffractie te benaderen is door extra richtingsspreiding aan de invallende golven toe te kennen en indien mogelijk, hoe groot deze extra richtingsspreiding moet zijn. Naast het effect van de diffractie op de golfhoogte zijn de effecten van richtingsspreiding van de invallende golven en van lokale opwekking van golven door wind onderzocht voor het golfveld tussen het eiland en de kust. Tussen het eiland en de kust ontstaat een schaduwgebied met een lagere golfenergie. In een situatie met wind en een wijd spectrum van invallende golven treedt er aanzienlijke reductie op in de golfhoogten achter het eiland vergeleken met de onbeschutte situatie. In het geval van een regelmatig golfveld (invallende golven vanuit een richting) heeft golfdiffractie een aanzienlijk effect op het golfveld achter het eiland. Als de invallende golven uit een richting komen, berekent het refractie-diffractie-model GREON iets hogere golven in de schaduwzone van het eiland dan het refractie-model HISWA met een smal richtingenspectrum. Het effect van diffractie is het grootst dicht achter het eiland. In het geval van een regelmatig golfveld kan de diffractie benaderd worden door extra richtingsspreiding aan de invallende golven in het refractie-model HISWA toe te kennen. Vlak achter het eiland blijkt de richtingsspreiding die de diffractie het best benadert groter te zijn dan verder achter het eiland. De best passende richtingsspreiding in HISWA voor de verschillende situaties en locaties, is slechts een schatting en vertoont nauwelijks een uitgesproken trend. Bij een wijd richtingsspectrum van invallende golven werd geen verschil gevonden tussen de golfhoogten berekend met het refractie-diffractie-model GREON en de golfhoogten berekend met het refractie-model HISWA met een vergelijkbare richtingsspreiding, zodat er geen effect van golfdiffractie kon worden aangetoond. De richtingsspreiding van de golven achter het eiland overstemt blijkbaar het effect van golfdiffractie. Het effect van wind (11 m/s) uit westelijke richting loodrecht op de kust op de golfhoogte in het schaduwgebied tussen het eiland en de kust is onderzocht. Het model CREON is weinig geschikt voor het berekenen van het effect van wind op de golfhoogte in een beschut gebied bij afwezigheid van oude golven. Verder achter het eiland is de invloed van de wind op de golfhoogte groter dan dicht achter het eiland als gevolg van de grotere strijklengte over het water. Het golfklimaat in de Noordzee bestaat uit onregelmatige golven die ontstaan door een relatief dichtbij gelegen windveld. Bij de aanleg van een eiland in de Noordzee zal de invloed van diffractie op het golfveld tussen het eiland en de kust minimaal zijn. Richtingsspreiding van golven en lokale opwekking van golven door wind hebben een overheersende invloed op het golfveld achter het eiland. Door de beschutting van een eiland in de Noordzee verandert de kustlijnligging in een wijd gebied achter het eiland. In het schaduwgebied van het eiland voor de kust van Noordwijk zal er aanzanding plaatsvinden van de kust voor Noordwijk en erosie van de aangrenzende kustgedeelten voor Katwijk en ten zuiden van Zandvoort. Beheersmaatregelen in de vorm van zandsuppleties zijn nodig om de aanzanding en erosie tot een aanvaardbaar niveau te beperken. Divergentie en contractie van de stroming rond het eiland heeft tot gevolg dat er een erosiegebied rand het eiland zal ontstaan met diepe erosiekuilen bij de hoeken van het eiland. Adequate bodembescherming van de oevers van het eiland is daarom noodzakelijk. De invloed van de golfdiffractie op het golfveld achter het eiland en dientengevolge op veranderingen in de kustlijnligging is gering. Bij de planning voor de aanleg van een eiland in de Noordzee hoeft nauwelijks gewicht toegekend te worden aan het effect van golfdiffractie.","diffraction; island; North Sea","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:53c10550-4d5b-47ef-af38-04097a1c5ada","http://resolver.tudelft.nl/uuid:53c10550-4d5b-47ef-af38-04097a1c5ada","North Sea temperature modelling with SST forcing","Goede, E.D. de","","1999","","zeewatertemperatuur; seawater temperature; temperatuurmeting; temperature measurement; gelaagdheid; stratification; North Sea","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:26fe1f23-7ad3-4e09-ae66-de4018aea394","http://resolver.tudelft.nl/uuid:26fe1f23-7ad3-4e09-ae66-de4018aea394","Validation of a 3D temperature model for the North Sea with in-situ data and remote sensing data","Vos, R.J.; Goede, E.D. de; Uittenbogaard, R.E.","","1999","","temperatuurmeting; temperature measurement; zeewatertemperatuur; seawater temperature; remote sensing; remote sensing; North Sea","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:94b7ab96-08e3-4208-a0da-d0d96dc271c5","http://resolver.tudelft.nl/uuid:94b7ab96-08e3-4208-a0da-d0d96dc271c5","Het poldermodel in de luchtvaart","Sommeling, B.","Bezuyen, K.G. (mentor); Tutuarima, W.H. (mentor); Vrijling, J.K. (mentor); De Ridder, H.A.J. (mentor)","1998","De infrastructuur voor de luchtvaart in Nederland dreigt tekort te gaan schieten. Er zijn in de media en in de Tweede Kamer grate discussies gaande over het hoe, waar en waarom van een uitbreiding. In dit afstudeerproject is gekeken naar de mogelijkheid van de (gedeeltelijke) verplaatsing van de luchthavencapaciteit naar een luchthaven in de Noordzee. De locatie in de Noordzee is gekozen omdat hiermee het best kan worden voldaan aan de gestelde eisen. Zo mag de afstand tot Schiphol niet te groot zijn en moeten geluidsoverlast en veiligheidsrisico's worden geminimaliseerd. De exacte locatie is 10 km uit de kust, iets ten noorden van Noordwijk, de waterdiepte is hier 16 meter (zie bijlage 10-11). Als eerste is bepaald aan welke capaciteit de luchthaven zal moeten voldoen. Verwacht wordt dat de luchthaven in de Noordzee in eerste instantie naast Schiphol functioneert en later, als de luchtvaartindustrie nog verder is gegroeid en de eisen rond Schiphol verder zijn verhoogd, als enige grote luchthaven in Nederland zal functioneren. In het eerste geval is een capaciteit van 21 miljoen passagiers en 222.000 vliegbewegingen per jaar nodig. Dit kan worden bereikt met een vliegveld met een configuratie van twee banen, haaks op elkaar. Een baan met de richting 070-250 en een met de richting 160-340. Voor het tweede geval, met groei naar een capaciteit van 70 miljoen passagiers en 650.000 vliegbewegingen per jaar, zijn vijf banen nodig. Hiervoor is een configuratie met twee keer twee parallelle banen in de richtingen 070-250 en 160-340 en een baan in de richting 030-210 het aantrekkelijkst (zie bijlage 10-1). Aan de hand van de genoemde configuraties is bepaald op welke wijze een ondergrand voor een dergelijk vliegveld is te realiseren. Er zijn drie concepten beschouwd die hiervoor perspectief bieden: een polder, een opgespoten eiland en een constructie op palen. Het blijkt dat voor het polderconcept het minste materiaal is benodigd en dat, bij een uitgekiende plattegrond van de polder, uitbreiding van de capaciteit binnen de oorspronkelijke omtrek heel gemakkelijk is. Ook is in Nederland meer dan voldoende kennis beschikbaar voor een succesvol ontwerp. Nadeel van dit concept is dat er kwel de polder binnenstroomt die weer naar buiten moet worden gepompt. Het opgespoten eiland is een beproefd concept dat in de Nederlandse situatie zonder veel problemen uitgevoerd kan worden. Het concept is echter duurder dan een polder indien een uitbreiding noodzakelijk wordt. Een constructie op palen in zee, die zo groot is als nodig is voor een vliegveld, is nog nooit gebouwd. Dit wijst er op dat er in dit geval wellicht onvermoede problemen met stabiliteit of onderhoud kunnen optreden. Ook dit concept blijkt uiteindelijk duurder dan het polderconcept. Conclusies: - Voor de aanleg van een uitbreiding van de Nederlandse luchthaveninfrastructuur is de aanleg van een vliegveld op een locatie in de Noordzee het interessantst. - Dit is technisch op verschillende wijzen haalbaar, de uitvoering als polder lijkt hiervoor de meest aantrekkelijke. - De kwel die de polder zal binnendringen is niet te hoog voor een economisch rendabele exploitatie. Dit geldt indien de correcte aannames zijn gemaakt van de doorlatendheid van ondergrond en dijkmateriaal. - Indien men de polder wil beschermen tegen te hoge kwel is het afdichten van het buitentalud van de ringdijk het meest effectief. - Pompen is goedkoop, hierdoor is een polder uiteindelijk goedkoper dan de andere alternatieven.","reclamation; airport; North Sea; polder; landfill","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:cda9b888-d60e-41aa-a95b-c9d988e48d1f","http://resolver.tudelft.nl/uuid:cda9b888-d60e-41aa-a95b-c9d988e48d1f","Artificial island in the North Sea and options for coastal development","Stive, M.J.F.; Dijkman, J.P.M.; Baan, P.J.A.; Villars, M.T.; De Graaff, R.F.","TU Delft","1998","A large-scale project such as the construction of an offshore island requires careful consideration not only of the direct effects of such intervention, but also of the implications for the further evolution of the Dutch coast. It is found that the construction of an offshore island is technically possible and - i f optimally shaped and carefully placed - would have only limited effects on the marine and coastal environment which could be compensated for. I f only the island were built, the already limited resilience of the Dutch coast would be even further decreased, because more coastal maintenance will be necessary. But i f the island is combined with other measures, like locally increasing the nearshore sand volumes by e.g. seaward protruding sand hooks, the resilience of the coast will improve. For this reason an indepth discussion is recommended about the long-term future of the Dutch coast.","artificial island; North Sea","en","report","","","","","","","","","","","","","",""
"uuid:d2054a22-b384-41d4-9b16-96362fb65ae1","http://resolver.tudelft.nl/uuid:d2054a22-b384-41d4-9b16-96362fb65ae1","Onderzoek naar thermocliene effecten op de Noordzee","Kester, J.A.T.M. van; Uittenbogaard, R.E.; Goede, E.D. de","","1997","","North Sea; thermische gelaagdheid; thermal stratification; stromingsmodellen; flow models; stoftransport; mass transport","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:6a31acec-9ef4-4841-aaf7-f2598b3081c5","http://resolver.tudelft.nl/uuid:6a31acec-9ef4-4841-aaf7-f2598b3081c5","Response of a shelf water to a traveling atmospheric pressure disturbance","Kirkegaard, L.C.","Battjes, J.A. (mentor); Booij, N. (mentor); Holthuijsen, L.H. (mentor)","1996","Every harbour has its own uniques et of natural frequencies depending on its geometry. If waves with frequencies close to one of these natural frequencies continue to enter from offshore for some time, the harbour will resonate. This phenomenon is called harbour resonance or seiching and the characteristic oscillations seiches. A moredetailed description of seiches and longwaves is given in Chapter 2. The Port of Rotterdam consists of a number of harbours connected through long and narrow channels, see figure 1.1. This system of harbours and channels is very sensitive to the resonance of long waves. The construction of the storm surge barrier in the Nieuwe Waterweg at the entrance of the harbour,along with other major projects in the area, is likely to change this response significantly and to the worse [9]. In recent years a lot of research has been concentrated on determining the effects of these changes more accurately. Little is known about the origin and statistics of the long waves,and often this has been of little or no interest to these studies. Instead, due to the lack of information, the seaward boundary condition, representing the incoming waves,is simply modeled by a harmonic wave. Predictions of seiches are presently made based on the known statistics and by assuming the worst possible situation that seiching will occur every time there is a storm [13]. The aim of this study is to investigate the influence of an atmospheric pressure disturbance on the response of a shelf water, and to find out if such a disturbance could be responsible for the generation of long waves in the North Sea, later causing seiches in the Port of Rotterdam. To achieve this objective, the response of a shelf water to an atmospheric pressure disturbance was investigated. First analytically, then numerically. The approach followed in these two parts is given below. The analytical study was desired to determine which parameters are of special importance to the problem in general. The applicability of the shallow water equations was therefore analyzed and the equations subsequently simplified to enable a simple one-dimensional analysis. The resulting equation was first analyzed without a pressure field, corresponding to free waves. Then two types of pressure fields were considered, viz. a harmonic, propagating pressure wave and a moving pressure jump. The harmonic,propagating wave is a classical forcing term when analyzing linear differential equations, and the pressure jump should resemble the pressure before and after the passage of a steep cold front. The numerical study was split up in a sensitivity study and a study of a real meteorological event, the passage of a cold front that occurred in the period 18th to 23rd of April 1993. Later this event caused some seiche activity in the Port of Rotterdam [12]. In the sensitivity test a simple one-dimensional model was set up. With this model a number of experiments were carried out to test the sensitivity of parameters like time step, grid spacing and bottom friction. In these experiments a harmonic, propagating pressure field like in the analytical study was used with wave length, period, velocity and amplitude based on the (expected) characteristics of the pressure field of the event mentioned above. The primary aim of the sensitivity test was to find a setup of the model for the calculations of the real event. In the cold front simulation the measured air pressure was used to simulate the passing cold front. Again some aspects of modeling this event were investigated to finally choose an appropriate model setup. The results of the final simulations were then compared to observations presented by Veraart [12] and the analytical results.","seiches; North Sea; Rotterdam Port","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:279488a8-73ec-40f0-ac06-fb4a8a6a12ac","http://resolver.tudelft.nl/uuid:279488a8-73ec-40f0-ac06-fb4a8a6a12ac","Extreme wave conditions along the coast of the Netherlands: Wave propagation models for the coast between Cadzand and Hoek van Holland","Dekker, J.; Hartsuiker, G.","","1995","","golfvoortplanting; wave propagation; golfmodellen; wave models; North Sea; Zeeland; Zuid-Holland","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:725a4dd5-0132-4267-88f7-7c03068fd71b","http://resolver.tudelft.nl/uuid:725a4dd5-0132-4267-88f7-7c03068fd71b","DMMS-ZEETOETS","Boon, J.G.","","1995","","North Sea; zeewaterverontreiniging; seawater pollution; waterkwaliteitsmodellen; water quality models","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:c6873e3d-5dad-4aa3-897b-9724c01c2f13","http://resolver.tudelft.nl/uuid:c6873e3d-5dad-4aa3-897b-9724c01c2f13","The maximum significant wave height in the Southern North Sea","Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.","Bouws, E. (contributor); Tolman, H.L. (contributor)","1995","The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is between 40 and 50 m/s (roughly equal to the wind speed in hurricanes but under different meteorological conditions). The extreme wave conditions in the southern North Sea have consequently been computed for a uniform wind field with a wind speed of 50 m/so The results of a sensitivity analysis show that the results of these computations are not very sensitive for this choice of wind speed. The wave conditions in this uniform wind field (uniform 5 m storm surge assumed) are at a maximum for a wind direction of 330"" N (i.e., from NNW). The significant wave height varies from 9.7 m at station BBR (near the Belgian border) and 14.2 m at station EUR. More information is available in tables and maps generated in this study. These values are approximately 25% higher than obtained with the second-generation wave model HISWA (default settings). To verify that the computed extreme wave conditions in the southern North Sea for the uniform wind field are physically realizable (even if the generating uniform wind field is not), a large number of computations has also been carried out with the second-generation wave model DOLPHIN-B for synthetic, extreme but realistic storms (800 storms in which the wind speed does not exceed 50 m/s). It was found with an additional computation with the WAYEWATCH-II model that the maximum significant wave height in the most severe of these storms (a relatively small, intense storm with a slight overshoot in wind speed to 51.8 m/s due to the incremental nature of the search procedures) are almost identical to those computed with WAYEWATCH-II model in the uniform wind field of 50 m/s wind speed. In the southern North sea (water depth less than 40 m), the ratio of significant wave height over local water depth, in the above extreme conditions is fairly constant and about 0.4. This ratio is maintained when a uniform storm surge is increased from 5 m to 6 m in the computations. The insensitivity of this ratio to variations in wind speed, wind field structure and storm surge level supports the notion that the maximum possible wave conditions in the southern North Sea are mainly controlled by the local water depth.","North Sea; wind waves; extreme waves; maximum wave","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","Section Environmental Fluid Mechanics","","","",""
"uuid:7e9b0bca-4903-4f11-a4ab-9c1dc738de81","http://resolver.tudelft.nl/uuid:7e9b0bca-4903-4f11-a4ab-9c1dc738de81","KSENOS: Aanpassing en uitbreiding van het modelinstrumentarium MANS voor toxische stoffen en eutrofiering in de Noordzee en de Nederlandse kustwateren","Bokhorst, M.; Boon, J.G.","","1995","","North Sea; waterkwaliteitsmodellen; water quality models; giftige stoffen; toxic matter; eutrofiering; eutrophication","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:6172326f-27a9-4ded-ac38-c136ac9a6381","http://resolver.tudelft.nl/uuid:6172326f-27a9-4ded-ac38-c136ac9a6381","Extreme wave conditions along the coast of the Netherlands: Wave propagation models for the coast between Hoek van Holland and Rottumeroog","Dekker, J.","","1994","","golfvoortplanting; wave propagation; golfmodellen; wave models; North Sea","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:29150d86-7406-43a0-b955-121657604b34","http://resolver.tudelft.nl/uuid:29150d86-7406-43a0-b955-121657604b34","North Sea estuaries as filters for contaminants","Zwolsman, J.J.G.","","1994","","United Kingdom of Great Britain & Northern Ireland; Nederland; Deutschland; Germany; North Sea; estuaria; estuaries; schadelijke stoffen; harmful matter; zware metalen; heavy metals; gechloreerde koolwaterstoffen; chlorohydrocarbons; aromatische koolwater","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:5bc9ce9b-369a-4835-ae17-493236cbaf9f","http://resolver.tudelft.nl/uuid:5bc9ce9b-369a-4835-ae17-493236cbaf9f","Gegevensbehoefte van Noordzee- en Waddenzeemodellen","Boon, J.G.; Bokhorst, M.","","1994","","Waddenzee; North Sea; waterkwaliteitsmodellen; water quality models; gegevensverwerking; data processing; modelijking; model calibration","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:b09040bb-6bbe-4512-8c4e-091c394cc3e2","http://resolver.tudelft.nl/uuid:b09040bb-6bbe-4512-8c4e-091c394cc3e2","Beheer en onderhoud MANS-instrumentarium: Fase 1","Hummel, S.; Most, H. van der; Verschuur, E.A.","","1993","","onderhoud; maintenance; waterkwaliteitsmodellen; water quality models; North Sea; computerprogramma's; software","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:ee5cf5d5-3695-435f-80bc-21fff71b3480","http://resolver.tudelft.nl/uuid:ee5cf5d5-3695-435f-80bc-21fff71b3480","Coastal zone management around the southern North Sea","Hillen, R.; Van de Wetering, B.G.M.; Verhagen, H.J.","","1993","The Southern North Sea is bordered by Great-Britain, France, Belgium, The Netherlands, Germany and Denmark. The North Sea basin and its adjacent shorelines are intensively used. Management of the basin and the coastal zone is therefore essential. Because of the small scale of the area, the dense population and the big scale of the interactions, international cooperation is vital. In this paper an overview is given of both the morphologic-physical interactions and the administrative interactions between the bordering governments. A complicating factor in Coastal Zone Management around the Southern North Sea is that CZM is highly connected to national spatial planning and to sea defence policy. In several of the bordering countries this is not a subject of the national government, but is handled on a regional level. This makes that we are dealing with more authorities involved. At this moment international agreement exists on most aspects of active use of the North Sea basin itself (navigation, oil and gas mining, fishery, cables, etc) and its major coastal shallow areas (like the Waddensea). However in the field of passive use (pollution by inflowing rivers, air contamination by heavy industry, risk by transport and processing of hazardous goods) still much has to be done. International agreement on the recreation along the coastal strip does not yet exist. Also the standards for coastal protection against flooding by storm surges and against chronic erosion vary in each country.","coastal zone management; North Sea; coastal erosion","en","conference paper","ASCE American Society of Civil Engineers","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:55d9afa5-0d85-4ad7-b816-90e75f8510be","http://resolver.tudelft.nl/uuid:55d9afa5-0d85-4ad7-b816-90e75f8510be","Long waves on the North Sea: An investigation of the requirements on measurements and data processing","Valk, C.F. de","","1992","","North Sea; gegevensverwerking; data processing; golfmeting; wave measurement; lange golven; long waves","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:dd4ae2c9-cabd-401d-9a21-7ae0f84028e6","http://resolver.tudelft.nl/uuid:dd4ae2c9-cabd-401d-9a21-7ae0f84028e6","De kalibratie van de Cd-koefficient in ZUNOWAK","Boogaard, H.F.P. van den","","1992","","North Sea; stromingsmodellen; flow models; waterkwaliteitsmodellen; water quality models; getijmodellen; tidal models","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:9334552b-d70e-445b-b644-9d9a9e61b8cf","http://resolver.tudelft.nl/uuid:9334552b-d70e-445b-b644-9d9a9e61b8cf","Effects of sea level rise on coastal evolution","Stive, M.J.F.","","1990","Using the Dutch coastal evolution in the Holocene upto the present as an example and a test case, a coastal evolution concept is proposed and materialized with which shoreline position changes for different sea level rise scenarios are predicted. The (more generally applicable) model applies to (quasi-)uniform coastal stretches. It accounts for morphodynamic processes from the shelf to the first dune-row, and integrates over coastal units of approximately 10 km alongshore length. The added value compared to earlier published concepts or models lies in the full inclusion of cross-shore and alongshore processes, and in the distinction between a - with respect to sea level rise - instantaneously responding active zone and a noninstantaneously responding central shoreface zone. Relevant differences have been found to exist between closed and interrupted coastal stretches. An important conclusion is that the cross-shore effective Bruun-effect is only of limited importance. This is especially true in the case of the interrupted coast. Longshore sand transport gradients are very important there. This is mainly connected with the sand demand which is placed on coastal stretches adjacent.","changes of level; sea water; coastal environment; holocene Landform evolution; transport; sand; Netherlands; North Sea; sea level rise","en","conference paper","Balkema","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:28fc6192-ed2a-4f19-b234-3ab9eb3ed97d","http://resolver.tudelft.nl/uuid:28fc6192-ed2a-4f19-b234-3ab9eb3ed97d","De storm van 1953 gesimuleerd met het Continental Shelf Model","Gerritsen, H.; Ronde, J.G. de","","1989","","stormvloeden; storm surges; simulatie; simulation; numerieke modellen; numerical modelling; North Sea; Zeeland","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:98eded3d-95df-4a0b-a2a4-be4029a08a73","http://resolver.tudelft.nl/uuid:98eded3d-95df-4a0b-a2a4-be4029a08a73","Investigation of surge-tide interaction in the storm surge model CSM-16","Bijlsma, A.C.; Bruinsma, R.; Vatvani, D.K.","","1989","","stormvloeden; storm surges; numerieke modellen; numerical modelling; North Sea; getijden; tides; getijvoorspelling; tide prediction","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:08798beb-4b70-49e3-bb63-31500ab3eae2","http://resolver.tudelft.nl/uuid:08798beb-4b70-49e3-bb63-31500ab3eae2","Regeling stofstromen zout: Voorstel voor aanpassing en aanvulling modelinstrumentarium voor toxische stoffen","Pagee, J.A. van; Markus, A.A.","","1988","","North Sea; zeewaterkwaliteit; seawater quality; toxicologie; toxicology; dispersie; dispersion; zoutgehalte; salinity","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:0525defa-c5f4-415c-861d-d798cb7b9145","http://resolver.tudelft.nl/uuid:0525defa-c5f4-415c-861d-d798cb7b9145","Data Report of Current, Temperature and Pressure Observations: Stratified Central North Sea 1980-1982","Maas, L.; Van Haren, H.","TU Delft","1986","During springs, summers and autumns of 1980,1981 and 1982 a collaborative study on the seasonal stratification of the Central North Sea was performed by the Netherlands Institute for Sea Research, the Institute of Meteorology and Oceanography Utrecht and the Royal Netherlands Meteorological Institute. This report lists mooring positions, local depths, meterdepths, operational periods and sampling periods of current meters, pressure gauges and thermistor chains. Additional current meter datasets on periods not covered in this data report exist with the Royal Netherlands Meteorological Institute, the periods shown here being characterized by the existence of simultaneous current, temperature and pressure records. Hydrographic surveys are described by Maas (1981) and van Aken (1981, 1983a). A description of the meteorological circumstances can be found in Kleverlaan (1982) and van Aken (1983b).","data; North Sea; currents; temperature; pressure; water depths; measurements; observations","en","report","Instituut voor Meteorologie en Oceanografie","","","","","","","","","","","","","56.351762, 3.031393"
"uuid:2c8f8bb1-95c5-4777-a751-5e410eeba165","http://resolver.tudelft.nl/uuid:2c8f8bb1-95c5-4777-a751-5e410eeba165","Pushover analysis of a fixed steel offshore platform - Part I: Beam-column and strut elements in the INTRA program. Part II: Piles and pile groups under extreme loads","Jansen, J.D.","Van Douwen, A.A. (mentor); Blaauwendraad, J. (mentor)","1986","Part I: The computer program INTRA models the collapse behavior of trusswork offshore structures with the aid of two types of elements: 'Beam-column' elements, designed to simulate bending dominated failure of structural members, and 'strut' elements, that can represent normal force dominated failure. The behavior of both types of INTRA elements has been investigated by comparison with the results of analytical solutions and of the MARC finite element program. A satisfying performance has been found for the beam-column element BEMC and the strut element ISTR. A Fortran routine has been established to generate the required input parameters for INTRA strut elements, resulting in more exact input values than can be derived with the aid of the default property generation. A parameter study has been carried out to the behavior of strut elements under conditions that may occur in the modelling of a large North Sea platform. It appears that lateral loads and imposed end rotations each may result in a maximum reduction of buckling strength of 15%, but that, however, the average reduction is much lower. Also the post-buckling strength is only modestly influenced. A plane frame pushover analysis has been performed with both the INTRA and the MARC programs. The influence of schematizations in INTRA strut elements on the overall structural beahavior appears to be acceptably small. However, serious numerical problems occurred during the INTRA analysis, resulting in a too low prediction of the ultimate load of the platform. Part II: As a preparation to pushover analysis of a complete fixed steel offshore structure, failure of the foundation has been analyzed in a qualitative way. Structure-foundation interaction is considered and some methods are treated to describe load-deformation behavior of piles loaded up to failure. Main attention is paid to methods in conjunction with the computer program INTRA. Computational rules to achieve load settlement curves for pile groups under extreme loads have been derived with the aid of modified t-z curves. Alternatives are presented to model the foundation in both extensive and more simplified ways.","pushover analysis; offshore platform; steel structure; beam-column element; strut element; buckling; ultimate load; reserve strength; North Sea platform; INTRA program; MARC program; soil mechanics; foundation engineering; pile; pile group; failure; extreme load","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","Steel Structures / Structural Mechanics","",""
"uuid:ae2618c8-9f15-44fa-94bf-e60ffe05a55e","http://resolver.tudelft.nl/uuid:ae2618c8-9f15-44fa-94bf-e60ffe05a55e","Impact of ERS-1 observations on wave forecasting in the North Sea","Bouws, E.; Komen, G.J.; Nooren, G.J.L.","","1984","A rather large number of conventional observations is available for the North Sea. Yet a comparison with the coverage of ERS-1 shows that its data will be a valuable addition to the existing data, especially in the north. The wave forecasting methods in use for swell forecasting in the southern North Sea suffer from a lack of data from the Norwegian Sea. This is illustrated with an example of model mis-prediction. One can conclude that the amount of data from ERS-1 in the Norwegian Sea will certainly improve swell forecasting in the North Sea.","ERS-1, North Sea, wave forecast, swell forecast, wind- and wave observations","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:31a1f9b9-532d-487a-bd71-303d285e27c4","http://resolver.tudelft.nl/uuid:31a1f9b9-532d-487a-bd71-303d285e27c4","Offshore siting of windenergy conversion systems","Verhagen, H.J.","TU Delft","1980","In a densely populated country such as The Netherlands it is almost impossible to install large numbers of large windturbines on the mainland. That was the main reason to investigate the possibilities of siting the windturbines offshore on the Dutch part of the North Sea Continental Shelf, with a further advantage of a higher windfactor. The investigations comprised the questions of how and where to install large windturbines in large numbers, what the costs will be and how the production and installation should be organised. Several types of structures for supporting the windturbines have been reviewed in steel and/or concrete, floating, resting on the seafloor or piled into the seabottom. The North Sea usage for shipping, fishery, etc. has been compiled and the several activities have been considered for their possible conflicts with windturbine parks. It was found that three regions were available with as 1 ittle conflicting usage as possible. Finally, the findings have been evaluated and some options were selected. For very large numbers of windturbines (5000 are being considered) the cylindrical steel column structure was found the best option, taking maintenance of the structures into account. Depending on the soil characteristics in the regions considered the structure will be piled into the seabottom or wil 1 be resting on the seafloor with the lower part being a sandfil led concrete caisson. Special devices have to be developed in order to install the windturbines in a streaming production scheme of one or two per day! The costs of offshore siting are rather high. For single production the costs are estimated at 4 to 4.5 mill ion guilders (2 guilders~ 1 U.S. dollar). For streaming production the costs are expected to be reduced to 3 or 2.5 mill ion guilders. Roughly these are the costs for offshore siting!","wind enery; wind turbines; North Sea; costs","en","report","Hydronamic & RSV-research","","","","","","","","","","","","",""
"uuid:1a1e9a38-e064-48b9-9918-922d02537f50","http://resolver.tudelft.nl/uuid:1a1e9a38-e064-48b9-9918-922d02537f50","Industrial island in the North Sea","","Hydronamic b.v.","1976","Extensive feasibility study for the construction of an artificial island in the North Sea, some 50 km offshore of Hook of Holland. Main purpose of this island was to create deep-water area for heavy industries. Contains legal and economic considerations, as well as a detailed design.","North Sea; Artificial island; Industrial island; NSIG; Reclamation","en","report","North Sea Island Group","","","","","","","","","","","","","52.25, 3.48"
"uuid:83e463ec-eaf5-4c74-b720-6733dd311833","http://resolver.tudelft.nl/uuid:83e463ec-eaf5-4c74-b720-6733dd311833","Sea Island Project","","","1972","Feasibility study for the construction of an artificial island in the North Sea, some 50 km offshore of Hook of Holland. Main purpose of this island was to create deep-water area for heavy industries as well as an area for waste disposal. Contains legal and economic considerations, as well as a detailed design. First feasibility study, later followed by a more extensive study. Volume 1 is on “the building of islands in the open sea offers possibilities for industrial development”, Volume 2 is on “A solution for the waste disposal problem”. Volume 3 is an artist impression (artist: Jan Lenoir, 1972)","artificial island; North Sea; industrial island; Reclamation","en","report","Bos Kalis Westminster Dredging Group","","","","","","","","","","","","","52.25, 3.48"
"uuid:1ec58044-5e49-447e-b956-223d1807fd75","http://resolver.tudelft.nl/uuid:1ec58044-5e49-447e-b956-223d1807fd75","Update Offshore Wind Atlas: Implementing a variable sea surface roughness","Donkers, J..A.J.","Bijl, H. (mentor); Brand, A.J. (mentor)","","In 2005 the Energy research Centre of the Netherlands (ECN) published its first version of the Offshore Wind Atlas of the Dutch part of the North Sea [3]. This version has been updated and improved using longer time series and another approach for the calculation of the roughness of the sea surface. In contradiction to other Wind Atlases which are based on measurements [28], use is made of data from the Numerical Weather Prediction model Hirlam. Measurements of wind speeds and directions are only used to validate the Wind Atlas. For the Offshore Wind Atlas, the Hirlam data is interpolated where for the vertically interpolation use is made of the Businger-Dyer profiles in combination with the Monin-Obukhov length [3]. One of the required parameters for the interpolation is the surface roughness. For land, it can be assumed constant while for sea it is variable. In the previous version of the Offshore Wind Atlas, the sea surface roughness has been determined using Charnock’s relation [9], where the so-called Charnock parameter is constant. In the new version, the equation of Hsu is introduced which states that the Charnock parameter is variable and dependent on the wave steepness i.e. the wave height divided by the wave length [19]. Assuming that the North Sea is a shallow sea and using the general wave equation, which relates the sea depth and wave length to the phase velocity of the waves, it was found that the wave steepness can be rewritten in a fraction of the wave height over the wave period multiplied by the square root of the sea depth times the gravitational acceleration. These quantities are derived from measured values which are interpolated to the location of interest. Using this approach, it is tried to improve the prediction of the wind speed distributions for a given location and altitude. Using wind measurements at several locations it was found that adding the wave data to the computations show a small improvement in the estimation of the wind speed distribution compared to the previous version of the Offshore Wind Atlas. For each measurement location and method, a two parameter Weibull distribution has been made, after which a comparison was done between the various shape and scale parameters. Generally, the scale parameter was overestimated by both versions of the Offshore Wind Atlas compared to the measurements. The cause of this behavior might be found in the data used to make the Atlas. The shape parameter is well predicted by the new version of the Offshore Wind Atlas due to the use of wave data. The influence of the wave data is found to be larger for lower altitudes than for higher altitudes. Besides Weibull distributions, also maps with average wind speeds are given by the Offshore Wind Atlas which are compared to older maps","Sea Surface Roughness; Wind Atlas; North Sea; Offshore","en","master thesis","","","","","","","","2010-11-17","Aerospace Engineering","","","","",""
"uuid:a5a5cd61-61dc-4d0e-b269-59aa953a5c1e","http://resolver.tudelft.nl/uuid:a5a5cd61-61dc-4d0e-b269-59aa953a5c1e","Statistical evaluation of wave conditions in a deltaic area","Svasek, J.N. (Rijkswaterstaat); Battjes, J.A. (TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering)","","1969","Coastal encineering problems concerning wind waves and~ell can be solved with the aid of hydraulic or mathematical models, The irregular wave field i.e. the state of the sea surface can be described in a sufficient way for engineering problems either by parameters such as significant wave height and mean wave period, or in the form of power spectrum function and the zero-moment thereof. A semi-empirical method is developed using transfer functions in order to deteruline tX-le boundary coned tions from wave measurements on a limited number of stations in all important points within a shallow sea area. An economical design is usually possible if the probability of occurrence of all parameters concerlled is known. The extrapolation of multidimensional statistical distributions of such parameters is often based on a relatively short period of field observations. The accuracy of the conclusions drawn from these observations influence the methods applied in the modelstudies i:u,ci the reliability of the economiGal decision. In this respect, an analysis of the available data is made with reference to Borne engineering and navigational problems in the South-Eastern part of the North Sea.","waves; North Sea; wave statistics","en","conference paper","","","","","","","","","","","","","",""
"uuid:c39e4430-b9da-41c2-9465-402d7a7686a6","http://resolver.tudelft.nl/uuid:c39e4430-b9da-41c2-9465-402d7a7686a6","Hydrography of the Dutch Wadden Sea","Postma, H.","TU Delft","1954","In this paper an attempt has been made to describe for the Dutch Wadden Sea water movement, transport of suspended matter and the cycle of suspended organic matter. Stress has been laid on the fact that these are related subjects, which therefore ought to be studied in combination. The discussion was based on observations made in the years 1949-1951 in the southwestern part of the area. A summary of the figures found from these observations is given in Table 23 in the report. For a good understanding of the results two facts appear to be of primary importance. First, there is a considerable exchange of water between Wadden Sea and North Sea, which is constantly at work to change Wadden Sea conditions, so that they approach those of the North Sea. Secondly, the concentration of light suspended material (silt) and of suspended organic matter is, notwithstanding this exchange, constantly higher in the Wadden Sea than in the North Sea.","hydrography; water movement; suspended transport; suspended organic matter; salinity; water quality; North Sea; Wadden Sea","en","report","Rijksuniversiteit Groningen","","","","","","","","","","","","","53.112124, 5.138997"