Climate change is accelerating coastal erosion, posing growing risks to infrastructure, ecosystems, and livelihoods across the world’s coastal zones. While global and regional studies increasingly provide projections of physical shoreline change, they often fail to integrate these with the spatial distribution of exposed assets or the potential for adaptation measures. As a result, their utility for informing where and how interventions, such as beach nourishment, could serve as viable adaptation options remains limited. Current research typically treats coastal erosion, exposure, and adaptation in isolation, leaving a critical gap in support for strategic coastal planning, where cross-country and cross-boundary insights could enable more coordinated and effective responses.

Here we present a continental-scale framework that integrates shoreline-change modelling, infrastructure exposure, and nourishment suitability to inform coastal adaptation across Europe. We first compile a novel database of 1060 historical nourishment interventions spanning 70 years, capturing the spatial distribution, implementation motives, and coastal contexts, including borrow area, nourishment type, and coastal type, under which nourishments have been applied. These insights inform a Nourishment Suitability Assessment Model (NSAM), which evaluates future nourishment potential based on four key factors: coastal type, policy context, sediment availability, and prior experience. We then project shoreline retreat by combining ensemble-based sea-level rise scenarios with ambient erosion trends derived from multi-decadal satellite imagery. The analysis applies the Bruun Rule with spatially variable coastal slopes and probabilistically combines sea-level rise-induced retreat with ambient trends. Applied to over 27000km of sandy coastline, this produces spatially explicit retreat projections that are intersected with exposure data to identify high-risk beaches.

Our results show that over 98% of transects are projected to erode under sea-level rise by 2100, with median shoreline retreat reaching -80m under SSP5-8.5. In contrast, ambient change alone shows strong regional variation, with 41% of historically unstable coasts eroding but a median accretion of 17m at the European scale. Combined projections indicate that while 85% of European sandy coasts are projected to erode by mid-century under SSP2-4.5, only 11.6% of these coincide with direct infrastructure exposure. By focusing on high-risk beaches, defined as stretches with over 1km of exposed assets, this research identifies up to 841 exposure hotspots (covering 1497km) under SSP5-8.5 in 2100, helping to prioritise sites in need of adaptation. Among these exposed sites, nourishment suitability varies considerably, shaped by both physical conditions and institutional capacity. The NSAM’s traffic light classification offers a first-order indication of where nourishment could form part of context-specific adaptation strategies, with suitability highest where conditions align with historical precedent and institutional barriers are low.

Key uncertainties are identified, particularly in slope representation and the assumed independence between ambient and sea-level rise-induced retreat. These highlight priorities for future model refinement. The framework demonstrates how integrated hazard, exposure, and adaptation assessment can enable more targeted and context-specific coastal management. By synthesizing forward-looking erosion risk with backward-looking adaptation practice, this work helps bridge the gap between impact assessment and action, showing that while many coasts are at risk, not all are equally suitable for nourishment, and a context-specific approach is necessary. ... Read more

This thesis focuses on 76 pairs of Cone Penetration Tests and boreholes that include Kreftenheye, out of a full database of nearly 200 pairs from TNO - Geological Survey of the Netherlands, generally reaching depths up to 40 meters. The thesis presents this analysis, showing the geological and geotechnical patterns and variations within the Kreftenheye Formation and how the integration of geological and geotechnical knowledge can lead to more effective engineering designs. ... Read more

Coastal regions, particularly beaches, are vital and dynamic areas for human activities. They serve various functions and are crucial barriers safeguarding coastal cities. However, the beach faces an increase in population and natural hazards caused by climate change are creating new challenges that coastal engineers are working to address.

This study introduces a new technique, SHORECAST (Satellite-derived Historical and future Orientation-based Relation for Estimating Coastline Adjustments and Sediment Transport), to enhance the Satellite-derived Shorelines (SDS). This technique is designed to estimate the shoreline dynamics in front of the shoreline and predict shoreline positions globally, offering a quick and accessible alternative to the existing models. The primary objective of this study is to employ shoreline position data obtained from SDS to estimate Longshore Sediment Transport (LST) and predict shoreline position quickly and effortlessly.

To achieve the study's objective, SHORECAST is developed and adapted into a multi-step framework using the annual dataset from the Shoreline Monitor of Luijendijk et al. (2018). The dataset assesses sandy and non-sandy beaches and their historical shoreline position at transects every 500 meters along the coast for the last 37 years. Only sandy shoreline evolutions are considered for the development of this new tool. First, a routine is developed to find coastal cells to which the research's aim could be applied. Secondly, multiple algorithms were deployed on the coastal cells to obtain the historical shoreline orientation and the LST. Combining these values leads to a correlation for predicting shorelines.

Out of all the coastal cells studies, three have been chosen: Nouakchott (Mauritania), Aveiro (Portugal) and Delfland (the Netherlands). The Nouakchott cell was split into a north and south side. These cells have in common that they all have a littoral barrier at one of the boundaries of the coastal cell with the assumption that there is no sediment transport. Due to this assumption, the LST could be calculated for each coastal cell. Nouakchott North experienced an annual sediment transport of 0.66 million m3 between 1985 and 2020, a volume increase of 23.01 million m3. Conversely, Nouakchott South experienced an erosion rate of 0.92 million m3 per year, resulting in a total loss of 32.36 million m3 over 35 years. In this same period, the Aveiro shoreline has accumulated a volume of 17.83 million m3 of sediment. In addition, the Aveiro shoreline displayed significant fluctuations compared to Nouakchott.

The Delfland coastal cell is the most complex coastal area among the three selected cases due to two littoral barriers at the boundaries and the anthropogenic measures in the past 37 years. This results in a volume increase of 45.55 million m3, similar to the beach nourishment volume of 46.51 million m3. As a result, it can be concluded that only the beach nourishment is visible in the SDS data, even though shoreface and dune nourishments have also been carried out during this period.

The findings indicate that the SHORECAST model, which incorporates the "Single-line theory" and specific boundary conditions, can generate multiple predictions. This makes it a universal tool for estimating sediment transport over time, even with future anthropogenic measures. It is important to note that not all assumed zero boundaries in sediment transport are zero in reality. Apart from SDS data, other shoreline position data can be integrated into the model to achieve similar results. Further research is needed to explore the possibilities of improving the understanding of different boundary conditions, thereby enhancing the obtained outcomes and the practicality of this study. An important suggestion is to explore the feasibility of identifying littoral barriers and other boundary conditions. This would make the developed model more robust and widely applicable. ... Read more

In recent decades, a growing number of shoreface nourishments have been carried out along the Dutch coast to mitigate coastal erosion. Designing shoreface nourishments requires a comprehensive understanding of their complex morphological evolution to develop optimal solutions. However, accurately predicting this evolution in Delft3D-FM has proven challenging. Excessive flattening of nourishments in morphological process-based models leads to an inaccurate representation of the cross-shore profile, and the implications of this inaccuracy on longshore predictions remain unclear. To address this issue, a hybrid model has been developed that seamlessly integrates a data-driven component into the process-based numerical model Delft3D-FM through Basic Model Interface. Contrary to previous study efforts, the focus is not on improving the representation of physical processes, but on incorporating a data-driven component into Delft3D-FM to more accurately represent observed behavior in cross-shore modeling. The presented modelling framework facilitates the prevention of excessive flattening of shoreface nourishments in Delft3D-FM by enabling user-defined manipulation of bed level changes during simulation. The hybrid model is then applied to reproduce a shoreface nourishment at the coast of Ter Heijde for two main objectives: (1) to demonstrate the proof-of-concept of a hybrid model approach and (2) to examine how inaccuracies in cross-shore modelling affect longshore predictions, thereby highlighting the added value of a hybrid model approach.
The results demonstrate the proof-of-concept of the hybrid model. Unlike the standard model, which showed excessive flattening of the nourishment, the hybrid model maintained its nourishment shape and followed observed cross-shore evolution over three months of morphological modelling. We found that a hybrid model approach has the potential to more accurately represent the nourishment’s lee effect, which plays a crucial role in the morphological response to a shoreface nourishment. By preventing excessive nourishment flattening, larger waves break earlier and/or more frequently in the hybrid model, causing a calmer wave climate in the lee of the nourishment compared to the standard model. As a result of increased wave sheltering, the flow velocity in the lee reduces which causes sediment supplied supplied by longshore currents to settle at a higher rate compared to the standard model, leading to increased sedimentation in the nourishment’s lee.
As a result of the enhanced representation of the lee effect, the alongshore redistribution of sediment differs between the hybrid model and the standard model. After three months of morphological modeling, differences of 10-25% between the models attributed to the nourishment sediment are observed in the lee of the nourishment. Additionally, the hybrid model shows a trend of increasing divergence from the standard model over time. This indicates a sustained added value of the hybrid model over time.
This thesis represents a contribution towards a data-integrated approach in process-based modelling of the complex evolution of shoreface nourishments, highlighting the potential added value of such an approach. Therefore, we anticipate this thesis to be a starting point for more sophisticated ways to incorporate accurate cross-shore evolution in numerical models in the context of shoreface nourishments. ... Read more

Rivers are essential for sustaining human life, preserving ecosystems, providing clean water, supporting energy production, offering recreation, and enabling transportation. Human interventions have led to the creation of so-called ‘engineered rivers’, such as the Dutch Rhine, which has undergone significant interventions over the past two centuries including straightening, dam construction, and the addition of fixed beds.

Fixed beds are found in the Dutch Rhine, such as in Nijmegen, St. Andries, and Spijk. Composed of non-erodible materials, they are strategically placed on the outer bends of rivers to enhance navigation by causing erosion in the inner bends, widening the river. Similar features worldwide include sediment nourishments and natural bedrock reaches.

This study investigates the large-scale morphodynamic effects of fixed beds, focusing on their influence on river slopes and sediment trapping. The research begins by examining the initial response of a fixed bed. A fixed bed results in (1) a sill-effect, (2) increased roughness, and (3) decreased mobility, and these effects are separated and treated individually. Conceptual models based on river dynamics theory are used to understand and predict how these effects contribute differently to the morphodynamic responses.

Following that, the study continues by looking into the transient and long-term response of a fixed bed using both conceptual and numerical models. These numerical models are created using the model system SOBEK-RE. The fixed bed-related effects are still considered separately with reference models created first and the effects integrated after. The reference model focuses on the transient state due to narrowing, where the slope decreases and the bed level increases. By doing this a comparison can be made of the fixed bed related effects with and without it. A similar process is repeated for a model run where the effects are all combined to assess their relative importance and the overall combined effect. The models reveal that all three effects contribute significantly to the fixed bed.

The model's key findings indicate that over a 50-year period, natural narrowing of the river reduces the slope by 4%. Introducing a fixed bed amplifies this effect: the upstream slope decreases by 3% and the downstream slope by 7%. This demonstrates that fixed beds alter the riverbed's slope, decreasing it downstream and increasing it upstream. At the upstream side of the fixed bed, it traps sediment caused by an M1-backwater curve. The height up to which this upstream sediment trapping continues is determined by two important parameters: the sill length and the sill height. However, the study acknowledges uncertainties related to model dimensions, sediment uniformity, discharge, and parameter choices. Real-world effects depend on the fixed bed's width, length, and protrusion relative to water level.

It is vital for water management authorities to recognize the importance of fixed bed structures, especially in extensively engineered rivers. This is because the fixed beds can result in significant and long-lasting changes to the riverbed.
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Coastal areas are highly dynamic systems sensitive to natural and anthropogenic change. The range of social, economic, and environmental functions served by diverse coastal environments makes understanding their geomorphology valuable. Parametric shape functions have historically been used to represent the cross shore profile of specific coastal environments. Geometric (consequential) parameters of these functions are often related to parameters representing key morphological drivers (causal parameters) to provide first order predictive capabilities. Advances in the application of data-driven modelling techniques presents opportunity to develop a unified characterization of cross shore morphology in diverse coastal environments. However, the ability to represent diverse profile geometries using a single parametric representation has not been observed. The aim of this study is therefore to evaluate the ability of parametric expressions to effectively characterize diverse coastal profile geometries. Here, a new parametric function is presented that can effectively represent key geometric attributes of diverse cross shore profiles. This function demonstrated high performance in the representation of both theoretical profile morphotypes (mean SSE = 0.04) and measured profile data from Narrabeen-Collaroy Beach, Australia (mean RMSE = 0.05 m) compared to eight existing parametric functions. Parametric values were effectively applied to group profiles with similar geometry using manual labelling and K-means clustering. The average profile of each cluster (i.e., the cluster centroid) provided a good representation of the grouped profiles, particularly when parametric grouping was used in place of empirical grouping. Correlation analyses between causal and consequential parameters demonstrated an ability to identify expected geomorphological trends using the new parametric function. Application of cluster centroids for correlation analysis provided amplified correlation strengths for expected geomorphological relationships, particularly when clustering with fitted parametric values. These results suggest that a parametric representation of the coastal profile has potential to characterize and group diverse profile geometries, and that causal-consequential parameter relationships have potential to identify geomorphological trends. The application of these results provide a foundation for the development of a predictive coastal profile model. This model could be trained using data from diverse coastal environments to predict coastal profile response to changes in the metocean climate related to human interventions and climate change. ... Read more

Soil liquefaction is a phenomenon in which an otherwise stiff, loosely packed, cohesionless soil loses its strength and behaves behaves like a viscous liquid in response to a change in stress conditions. This study focuses on liquefaction under monotonic load (i.e. static liquefaction) and not cyclic liquefaction. While the role of state variables such as relative density in liquefaction is well established, the importance of intrinsic soil properties (ISPs) is less clear. ISPs include grain size gradation, mineralogy and grain shape The critical state soil mechanics framework can be used to link these properties to liquefaction susceptibility. One approach to do so is the "Relative Contractiveness" (RC) concept proposed by Verdugo & Ishihara (1996). This thesis investigates the role of ISPs in soil liquefaction and tests the RC concept through a combination of statistical analyses, four case studies and a new experimental study.

The statistical analysis shows that an increasing fines content generally leads to greater relative contractiveness and especially at lower stress levels, indicating increased sensitivity to liquefaction. Particle shape plays a multi-faceted role in liquefaction susceptibility, as increased angularity may increase compressibility but also increase resistance to particle rotation and hence reduce the likelihood of flow behaviour. The mineralogy of soils was difficult to statistically analyse as the information is usually not given, but extra care should be taken when dealing with sands that are not made of quartz, as most index methods are based on quartz.

The case studies exemplified varied applicability and benefit per case. The Ijmuiden case demonstrated the limitations of field tests and critical state determination. It did indicate medium to high relative contractiveness for the tested soils. The Nerlerk berm failure demonstrated the importance of fines content in liquefaction susceptibility, as only the finer of the two soils used for the hydraulic fill liquefied. However, the geometry and differences in deposition method also played a role. For the Hollandsch Diep case environmental factors are ought to play a more important role in liquefaction rather than that the soil is intrinsically exceptionally susceptible to liquefaction. The Bangabandhu bridge case highlighted the limitations of compressive loading based methods as the soil was particularly weak in tensile loading. It also highlighted the importance of mineralogy and grain shape, as the presence of plate-like micaceous particles drastically reduced its strength.

The new experimental study investigated a soil from the Eastern Scheldt estuary in the Netherlands, a region historically notorious for liquefaction flow slides. Surprisingly, the sampled soil was not prone to liquefaction at all, showing strong dilative tendencies under triaxial compression.

In conclusion, this study suggests that the relative contractiveness concept could be used as a screening method for assessing liquefaction risk, rather than a deterministic method for designing parameters. However, further studies with extensive and consistent material characterization and critical state determination are needed to verify the validity of the relative contractiveness concept. Discrete element modelling of soils could also provide future opportunities for advancing our comprehension of the role of ISPs in liquefaction susceptibility.
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The study explores the potential impact of accelerated sea level rise on coastal flood risk in the Netherlands, particularly focusing on the Plan B NL2200 approach. Sea levels are expected to rise faster than initially thought due to factors like Antarctica's melting ice. The Sea Level Rise Knowledge Program in the Netherlands investigates consequences and mitigation strategies, including the categories 'protect-open,' 'protect-closed,' 'advance,' and 'accommodate.' The research compares the effectiveness of multiple spatial adaptation strategies, with a specific emphasis on the Plan B NL2200 approach, which envisions a Netherlands without dikes.

The study analyzes various spatial adaptation strategies, while focusing on extreme sea level rise and storm surge conditions, using a probabilistic model. The first part evaluates different spatial adaptation strategies in an idealized coastal polder, considering factors like spatial impact and flood risk mitigation. Findings suggest that strategies involving complete dike reinforcement are effective in reducing flood risk. The second part applies these strategies to the real case study of Walcheren, comparing damage, casualties, and affected people. The results indicate that the plain dike-ring strategy with an increased safety standard (P2) is the most cost-effective for preserving Walcheren entirely.

Regarding the Plan B NL2200 approach, the study concludes that, for Walcheren, it does not perform as the best strategy. The primary dike-ring strategy with tightened safety standards is more effective due to lower costs, reduced risks, and no land relinquishment. The study recommends maintaining the current strategy for reinforcing primary dikes while enhancing safety standards to protect Walcheren, including Middelburg and Vlissingen. However, the findings may not directly apply to other Dutch coastal areas due to location-specific factors, urging further research, including sensitivity analyses, exploration of additional spatial adaptation strategies, and consideration of societal aspects related to the Plan B approach. ... Read more

Over the years, InSAR has become an indispensable tool in the study of ground deformation, including volcanic deformation, and this continues to be the case in times of improved technology. Since the volcanoes on the Caribbean islands of Saba and St. Eustatius are active, the implementation of an InSAR-based monitoring system is crucial to enhance the spatial resolution of volcano monitoring beyond the capabilities of the ground-based monitoring network, for instance in the case of localized deformations such as dike intrusions. However, technical challenges arise in these tropical settings, caused by dense rainforest, atmospheric artifacts and terrain variability, posing serious challenges to the use of InSAR. Time series InSAR, including SBAS and PSI, can be used to overcome these limitations. A previous study has explored the use of PSI for monitoring, using the already available DePSI software. In this research, an SBAS approach within the Delft InSAR software framework is developed using state-of-the-art Python packages, including (sar)xarray, dask and zarr, and is used to assess whether there is capability to develop SBAS into a volcanic monitoring tool for Saba and St. Eustatius. In addition, a preliminary comparison between the SBAS and PSI methodologies is performed based on a theoretical and (semi-)quantifiable approach. This study combines data from two satellites operating at different wavelengths: Sentinel-1 (C-band) and ALOS-2 (L-band).

Assuming no ongoing deformation, based on GNSS results, the variability of the results around zero can be used as an indicator of precision. The results obtained through SBAS are promising, in particular for L-band, on account of e.g., extensive spatial coverage, efficiency and relatively low variability even with the presence of atmospheric and DEM components. Overall, the results reveal mm order deviations. In the event of volcanic activity, the expected deformation signals are in the range of cm-dm's and can therefore be detected, i.e., with an estimated minimal detectable deformation of 1.5 cm/year in the worst-case scenario. The implementation of three different coherence-based masking approaches-water, single and individual-give an indication of the level of robustness and reliability of the results. Generally, a relatively high level of consistency can be observed among the different masking results of ALOS-2 for both islands, for St. Eustatius following the correction of the unwrapping errors using two testing approaches: an interferogram removal approach and an adaptive approach based on the DIA procedure. The latter procedure allows for retaining all observations and their residuals and is therefore preferred. In contrast, the Sentinel-1 results reveal a lower level of consistency. It is suspected that this inconsistency mainly arises on account of the numerous unwrapping errors within the single masking approach. The individual masking approach appears to be less susceptible to unwrapping errors, however is more prone to outliers than the single masking approach. Further research, following the correction of the atmospheric component and DEM errors, may offer insights into the preferred masking approach. Overall, the use of L-band imagery shows potential, offering spatial coverage where C-band does not, even with limited ALOS-2 data availability and large temporal baselines. The preliminary comparative analysis with the PSI approach, based on the respective strengths and limitations from literature, spatial coverage, processing steps, precision and computational requirements, suggests that a hybrid method could prove to be advantageous to minimize (potential) signal loss, e.g. either from limited spatial coverage or spatial resolution, and enhance volcanic risk assessment. SBAS excels in the extensive spatial coverage, especially using L-band, providing nearly homogeneous coverage of St. Eustatius, even on the flanks of the Quill, and on the outer flanks Mt. Scenery on Saba. However, regardless of the mask, wavelength or method, acquiring coverage around the summit of Mt. Scenery on Saba remains challenging.

The study contributes to advancing InSAR time series analysis for the volcanic monitoring on Saba and St. Eustatius through the successful implementation of an SBAS approach within the Delft InSAR software framework based on state-of-the-art packages, the implementation and evaluation of new approaches to enhance the method in terms of the efficiency and robustness and a comparison with existing software. In addition, the software can be applied in a generic sense for various applications and can be extended for further improvements. ... Read more

Tailings storage facilities (TSF) are engineered structures that retain mixed waste material (known as mine tailings material) from mining processes in liquid or slurry form. One of the issues regarding TSF management is the lack of site investigation and sample analyses, which cause the uncertainty of geotechnical properties of mine tailings materials. For a proper operation of tailings storage facilities, the owner should study the material involved and understand the physical and chemical properties associated with it. In case of mine tailings dam failure, the resulting flood wave supposes an environmental, social and economical disaster for society.

Mine tailings dam break studies use numerical models to predict the flooding area and assess the possible damaged area. Historically, these studies were carried out according to Newtonian modelling principles, but the presence of solids within the fluid suggests that the resulting flood wave of a TSF failure should be treated as a non-Newtonian fluid. Absence of laboratory data regarding the geotechnical properties of mine tailings materials make difficult the prediction of such flood wave, since the composition of the mixture is unknown. Therefore, the aim of this research is to study the flow behaviour of mine tailings materials in case of failure of tailings storage facilities. Understanding the flow behaviour of the non-Newtonian fluid is essential to analyse the possible failure event for an existing structure, in order to plan and organise emergency procedures that anticipate and mitigate downstream damages. ... Read more

The Parisian urban region is currently experiencing Europe’s largest urban transition centered around a 200 km mobility network (the Grand Paris Express) and intended to project the city beyond its historic boundaries and into the 21st century. This inevitable urban restructuring is reconfiguration spatial, socio-political, and cultural relations between the urban center and the periphery but is also considerably affecting the ecological functioning of the larger riverine territory of the Seine Basin from which it depends on. This thesis investigates the ecological, geological, and hydrological consequences of material extraction needed to construct the Parisian Urban Project, looking most notably at sand and aggregate quarries used in the production of concrete. While this graduation project does not look to offer an alternative to extractivism, it looks at applying a material practice of repair on damaged landscapes to mend for past destructive actions and reintegrate post-extraction sites into a larger production system. This project first constitutes a joint narrative between the urban project of the Grand Paris and the territorial project of the Seine watershed. This relational outlook is intended to form nonlinear and dynamic links between the urban and the territorial, land and water, and culture and matter to uncover the uneven and exploitative practices occurring in and around the river system. This project then follows urban matter - materials associated with the construction of the urban - through a forensic exploration, associating socio-cultural crisis with political and economic agendas and their physical manifestation beyond the conventional urban boundaries, looking at cultural and physical forces applied on geologies and the processes of de/re-territorialization of matter. Finally, this thesis formulates a territorial vision embedding a new material cycle in the Seine River Basin and proposing a design intervention towards repair in La Bassée, the last remaining upstream wetland in the watershed. This vision provides a dual social and ecological rehabilitation of post-extraction sites towards an integrated multi-species riverine landscape adapted to the instabilities of the New Climatic Regime. ... Read more

Due to climate change, glaciers are melting on the Tibetan Plateau. These glaciers are the water source for big rivers as the Brahmaputra which stream towards the most densely populated area on Earth. Previous studies indicated that water surface heights of lakes connected to the glaciers are increasing in the north of the Tibetan Plateau, while they are decreasing in the south. Current literature does not provide a clear answer on the reason why the north and the south are behaving differently. For determining why the south is behaving different than the north, the processes in the basin should be identified and distinguished. For addressing what all the processes in the basin are, the waterbodies in the upper Brahmaputra should be monitored and their relation to the processes and the other waterbodies should be determined. For determining this relation it is of importance to first determine the lake surface heights and river surface heights in this area. This research focusses on determining water surface heights in the upper Brahmaputra and Nam Co basin (located in south of the Tibetan Plateau) using remote sensing, which is the preferred method since waterbodies in this area are difficult to reach for in-situ measurements.
In this study, data of ICESat-2 is used for water surface height measurements. The laser satellite mission ICESat-2 has been launched in 2018 and makes use of three pairs of beams. Lake surface heights are determined by first computing the water surface heights per beam and finally per ICESat-2 passing. Several additional steps to determine the river surface heights are required due to the slope of rivers. Therefore, the passing beams are clustered, resulting in several locations in the river which can be further analysed. It is found that river surface heights are harder to determine due to the presence of bars and shorelines. Therefore, the method for determining the river surface heights should only be used for non-braiding rivers.
A precision for both lake surface heights and river surface heights of 0.1 meters is found. This research found that ICESat-2 can have a contribution for determining lake and river surface heights due to its relatively good precision, but also due to its high spatial resolution. The ground-track spacing of ICESat-2 is lower than other satellite missions, resulting that ICESat-2 passes the most amount of lakes and river locations. In total the water surface heights of 299 lakes and 127 river locations are determined. This small ground-track spacing is at the cost of the temporal resolution resulting in large time gaps in the timeseries of the lakes and river locations. Therefore, a seasonal variation and generic water surface height curve will be difficult to assess. It is possible that ICESat-2 will miss the moments with the extreme water surface heights resulting in a misconception of the water surface heights. But, over a longer time period it may be possible to fit a generic water surface height curve through the water surface heights of lakes larger than 10 km² due to its higher amount of ICESat-2 passings. ... Read more

A large part of the Dutch coast, the barrier islands in the Wadden Sea included, would be eroding if the deficit in the total sediment budget was not compensated for through nourishments. Ebb-tidal deltas have an important function within the coastal system that make them of interest for coastal defence as a source and transport path for sand to the back-barrier basins and the island coastlines. As part of the Kustgenese 2.0 project, a pilot nourishment of 5.5 million m3 has been placed on the Ameland ebb-tidal delta. Improved understanding of sediment bypassing processes and the interaction with a nourishment is needed for strategic placement of nourishments in the future. In this thesis we analyse the high-frequency bathymetric dataset available at Ameland inlet between 2005 and 2020 and model the tide- and wave-driven transport pathways using to SedTRAILS to determine how sediment bypassing works under natural circumstances and under the influence of a nourishment. A new series of conceptual models has been proposed. These show that the formation and growth of a series of ebb-shields on the western side of the ebb-tidal delta plays an important role in sediment bypassing. Their development gradually results in transport pathways connecting the western side of the ebb-tidal delta to the major transport pathway along the ebb-delta front, which forms a direct connection to the Ameland coast in 2017. The influence of the pilot nourishment on sediment bypassing processes is limited, adding volume to the system but not altering the existing transport pathways. Transport pathways show that sediment from the nourishment eventually reaches the Ameland coast and is unlikely to feed the Terschelling coast or the tidal basin. This is valuable knowledge for the future sustainable coastal management of Ameland inlet, which can also be extended to other inlets. ... Read more

While waves are propagating towards the shore and are interrupted by an obstacle like a groyne, they will turn around the tip into the sheltered region of the groyne. This sheltered region is called the shadow zone and contains a reduced wave climate. The turning of the waves is based on the lateral transfer of wave energy along the wave crest, caused by a gradient in wave height. This process is called diffraction. Breaking wave heights and angles inside the shadow zone will be influenced significantly because of wave diffraction. Since variations in breaking wave height and/or angle are responsible for gradients in the alongshore sediment transport, should the process of wave diffraction be taken into account while simulating the shoreline evolution in the vicinity of a groyne. Different methods were found to incorporate the effects of wave diffraction inside the coastline model ShorelineS.

The improved model performance of ShorelineS regarding a real-world case study is addressed by using the shoreline of Constanta, Romania. The consequence of incorporating wave diffraction effects onto the shoreline evolution of Constanta is demonstrated in detail. The accretion close to the Southern groyne and erosion near the Northern groyne is visible in the numerical result of the improved model. Therefore, matching the observed anti-clockwise rotation of the coastal cell. Without accounting for diffraction effects, this matching result was not achievable. The transition zone width is found to be an important factor in determining the coastline shape affected by diffraction. After calibration of this parameter, the numerical result demonstrated to be in almost perfect agreement with the observed coastline shape. The root mean square error and bias reduced with factors of 5.5 and 5 compared to the numerical result excluding diffraction effects.
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The rising demand for clean energy has drawn the attention for more geological research to low enthalpy geothermal applications in the Netherlands. A multi-scale reservoir characterization is carried out with the aim to understand the geothermal reservoir potential of the Triassic Main Buntsandstein (RBM) in the Tilburg area. Seismic data, well logs and petrophysical data are used to evaluate the reservoir architecture, stratigraphy, and quality of the potential Main Buntsandstein geothermal aquifer. It was found that the study area is located within a horst- and graben system bounded by normal faults where the top boundary of the RBM is located at depths of 1900 – 2100 m for the horsts and 3300 – 3500 m for the grabens. The horsts and grabens range from circa 3000 to 4000 meters in width. Well log correlations and thickness maps at RBM scale suggest thicknesses of the Subgroup from ca. 160 to 220 meter. The thickness of the Main Buntsandstein generally decreases on the horsts and increases towards the grabens, suggesting higher temperatures of up to 100° C and thicker sand units in the grabens. Thickness generally decreases on the horsts and increases towards the graben suggesting faults were active at time of deposition and better geothermal potential in the grabens due to greater depths and thicker RBM unit. The core analysis of the study showed that the potential Main Buntsandstein reservoir is composed of a variation of sand- and mudstones interlayers, which were deposited on a large fluvial-fan system terminating in a playa-lake environment towards the basin center. Four different facies associations were distinguished within the cores of wells AND-06, KWK-01, SPC-01 and WWN-01-S2. Optimal reservoir connectivity is, according to the facies architecture model, expected in the Lower Volpriehausen and Detfurth Sandstone Members due to the presence of stacked amalgamated fluvial fan sandstone facies. It appeared that aquifer quality does not correlate with increasing depth or stratigraphic position, although the Volpriehausen- and Detfurth Claystone Members display significant poorer reservoir properties. These members, which can be correlated at well distance due to its widespread deposition as playa-lake sediments, are likely to act as a baffle to flow in the subsurface. Best reservoir potential, considering petrophysical measurements on porosity and permeability, is within the fluvial fan sandstones of all facies associations whereas the fine grained cross bedded sandstones show best reservoir quality of all encountered lithofacies. The data showed highly variable measurements where highest mean values for the porosity (11 %) and permeability (105 mD) are encountered in the Lower Detfurth Sandstone Member of well HVB-01. It turned out that northern located wells of Tilburg (AND-06, KWK-01, WWN-01-S2 and SPC-01) showed considerable poor reservoir potential with mean values of below 10% and 10 mD for the porosity and permeability. The southern wells, however, appear to have generally higher reservoir properties compared to the northern wells suggesting better geothermal potential in the area south of Tilburg. ... Read more

About 80-90% of U.S. East Coast barrier beaches have experienced erosion in the last 100 years. South Carolina’s coastline forms no exception, a third of its developed shoreline experiences erosion. Among these eroding shorelines is Hilton Head Island, the second largest barrier island on the U.S. East Coast. Until now, erosion here has been addressed through traditional local beach nourishments. An alternative approach to the traditional nourishment method, are so-called feeder nourishments or feeder beaches. The potential advantages of the feeder nourishment concept over the traditional method are reduction of the nourishment frequency, containment of the ecological stress in a relatively small area, and a short to medium term increase of local available space for recreation and the environment. Given the potential advantages above, the residents of Hilton Head Island asked TU Delft to investigate the possibility of applying a feeder nourishment at their shoreline. Currently, a pilot project known as “The Sand Engine” is examined along the Dutch coast. Several studies into its morphological behaviour show that this feeder nourishment can be beneficial to the sediment budget of a larger coastal cell. Because of the promising results at the Sand Engine pilot project, it is tempting to state that a feeder-nourishment could also be applied at Hilton Head Island. The problem, however, is that the conditions at Hilton Head Island and the Sand Engine are different. There are two main differences between Hilton Head Island and the Sand Engine. First, Hilton Head is subjected to a relative calm wave climate in comparison to the Sand Engine. Second, the presence of two tidal inlets at Hilton Head, compared to a relative straight and uninterrupted coastline at the Sand Engine. As a result, the conclusions drawn from the Sand Engine pilot project do not necessarily hold for Hilton Head Island as well. The main objective of this thesis is to analyse the morphological behaviour of a feeder nourishment located at Hilton Head Island. First, to study its potential as a measure against erosion at Hilton Head. Second, to compare its morphological behaviour to that of the Sand Engine. And third, to be able to examine the potential of the concept for the Atlantic southeast coast of the U.S. in general. The morphological development of a feeder nourishment at Hilton Head Island was simulated with Delft3D over the course of 1 year for different model scenarios, with varying forcing conditions and varying bathymetric features. The effect of the relative calm wave climate at Hilton Head Island in comparison to the Sand Engine is twofold. First, the contribution of wave forcing to the total erosional volume of the feeder nourishment after 1 year is smaller as compared to the Sand Engine. Eliminating all driving forces besides wave forcing reduces the total erosional volume to 58% at Hilton Head, in comparison to 75% at the Sand Engine. Second, the contribution of storm events to the total erosional volume after 1 year from the feeder nourishment is smaller at Hilton Head compared to the Sand Engine. It measures 23% at Hilton Head, in comparison to 60% at the Sand Engine. To assess the impact of the two tidal inlets on the feeder nourishment, they were closed off. Closing of the tidal inlets eliminates any (potential) residual currents. This reduces the total amount of sediment that is eroded from the feeder nourishment by 7% compared to a reference scenario with open tidal inlets. Before construction of the feeder nourishment the coastline south of the nourishment experienced a net sediment outflux of approximately 4000 m3/year. After construction of the feeder nourishment, the southern section experiences a net import of sediment of approximately 100.000 m3/year. Meaning that the southern section, on average, has transitioned from being erosive to accreting. Up to 500 meter away from the nourishment the cross-shore profile shows a seaward movement of the shoreline position of approximately 25 m compared to the original situation without nourishment. Before construction of the feeder nourishment the coastline north of the nourishment experienced a net sediment outflux of approximately 40.000 m3/year. After construction of the feeder nourishment, this net outflux of sediment has decreased to approximately 25.000 m3/year. This shows that the feeder nourishment is feeding sediment to the northern section, but at a rate that is not sufficient to keep up with the underlying erosion rate. The northern domain, on average, still experiences a sediment outflux and stays erosive. Roughly 50 m of coastline directly north of the feeder nourishment experiences a seaward movement of the shoreline position. However, moving further away from the nourishment, the shoreline remains erosive. The Atlantic southeast coast of the United States is made up of North Carolina, South Carolina, Georgia and Florida’s east coast. The South Carolina and Georgia coastline are comparable in both hydrodynamic conditions and geomorphological setting. They are mixed-energy coasts, broken up by numerous tidal inlets, and home to short barrier islands with complex sediment transport patterns. North Carolina’s and Florida’s east coast are wave-dominated, with relative straight shorelines. Which is distinctly differences from the conditions found at Hilton Head Island. Therefore, the potential of the feeder nourishment concept is only analysed for South Carolina’s and Georgia’s coastline. The presence of numerous tidal inlets leads to strongly varying conditions along the coastlines of both states. The developed locations along South Carolina’s coastline that require erosion mitigating measures are south Debidue beach, North Island, Hunting Island and Daufuskie Island. Along Georgia’s coastline there are only some erosion hotspots along Sea Island’s coastline that require erosion mitigation measures. The wave climate at all the above mentioned location is similar to Hilton Head. A southeast swell, with a narrow range of directions and an annual wave height of roughly 1,0 m. The same goes for the tidal range. The results at Hilton Head show that erosion on adjacent coastal sections can be lessened and/or prevented by constructing a feeder nourishment. Given that these locations are subjected to similar conditions, the construction of a feeder nourishment could potentially be an effective measure to prevent or lessen the occurring erosion. ... Read more

All over the world coastal communities are at risk due to sea-level rise and intensifying weather conditions. Many sandy beaches are eroding as a result of human-induced factors. Currently, the preferred coastal protection measure in the United States are beach nourishments. In Europe, there also is a general shift from hard to soft coastal protection measures. However, beach nourishments are not a long-term solution. Recently, in the Netherlands, a new concept called a large-scale (mega-feeder) nourishment has been introduced (the Sand Engine). Numerous studies on this new concept have been conducted. However, not for a mega-feeder nourishment nearby a tidal inlet system. About 10\% of the world's beaches consist of barrier islands. Emphasizing the importance of investigating the development of a mega-feeder nourishment nearby a tidal inlet system, under various hydrodynamic conditions. Therefore the research question is as follows: “How does a nearby tidal inlet system influence the development of a mega-feeder nourishment?” The research question is answered by investigating the effects various hydrodynamic conditions have on the development of a mega-feeder nourishment nearby a tidal inlet system. This is done for fixed morphodynamic features, such as the dimensions of the tidal basin and the dimensions and orientation of the tidal inlet. The only variable morphodynamic feature is the alongshore position of the mega-feeder nourishment. Four distinct hydrodynamic scenarios are modelled to investigate their effects on a mega-feeder nourishment. The tidal range (η), significant wave height (Hs), peak wave period(Tp) and peak wave direction (Dp) are varied. This resulted in the following hydrodynamic scenarios: 
•Mild wave conditions: (η = 1.5m; Hs=1.0m and Dp=0°);
•Oblique wave conditions: (η = 1.5m; Hs=1.0m and Dp=-45°);
•Storm wave conditions: (η = 1.5m; Hs=variable and Dp=0°);
•High tidal range: (η = 3.0m; Hs=1.0m and Dp=0°).
These hydrodynamic conditions and their effect on a mega-feeder nourishment are modelled by utilizing a process-based numerical model called Delft3D. In Delft3D, two locations of the mega-feeder nourishment per hydrodynamic scenario are evaluated. A mega-feeder nourishment is placed at an alongshore distance of 2 kilometers and 5 kilometers from the tidal inlet. This to get insight in the tidal flow nearby a tidal inlet and up to what alongshore distance this tidal flow affects the development of a mega-feeder nourishment. The hydrodynamic conditions were simplified, meaning steady wave characteristics and a single M2 tidal constituent. Using real time-varying hydrodynamic conditions yields similar results compared to the simplified hydrodynamic conditions. Therefore, simplifying the hydrodynamic conditions is justified. The results show that there will be additional erosion near a tidal inlet if the mega-feeder nourishment is located inside the influence of the tidal inlet. The influence is the alongshore distance where the currents owing to the tidal inlet (residual currents) still affects the total alongshore sediment transport (larger than 50 m³/6y/m). The alongshore distance of the influence increases with an increasing tidal range (tidal prism). However, there is no shoreline retreat owing to the tidal inlet at the location (2km from the tidal inlet) of the mega-feeder nourishment over a time period of 6 years. Only the adjacent coast on the inlet-side of the mega-feeder nourishment erodes significantly more than without a tidal inlet, with an increasing magnitude in the shoreline retreat towards the tidal inlet. Hence, it is expected that if the mega-feeder nourishment is placed close to the tidal inlet (i.e. several hundreds of meters), then the influence of the currents owing to the tidal inlet will enhance the shoreline retreat at the location of a mega-feeder nourishment. To conclude, the tidal inlet does influence the development of a mega-feeder nourishment nearby a tidal inlet (order several hundreds of meters). However, this is not necessarily seen in the retreat of the shoreline but instead in deeper depth contours. The governing process in the sediment transport at a mega-feeder nourishment is the incident wave angle for small tidal ranges (η < 1.5m) and mild wave conditions (Hs > 1m). However, for a large tidal range (η > 3.0m) the residual currents owing to the tidal inlet will become the governing process.
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With an increase in the demand for heat energy, and the growing conscience of the world to reduce CO2 emissions, the transition to cleaner energy alternatives has gained momentum. In the Netherlands, the potential for cost-effective geothermal heat extraction from sedimentary aquifers has led to the exploration of siliciclastic Triassic reservoirs in the West Netherlands Basin and Roer Valley Graben for their suitability. This thesis primarily focuses on two geothermal target wells namely NDW-01 and NLW-GT-01. These wells lie in the Nederweert and Westland areas respectively.NDW-01 comprises of 292m thick sandstone package which is scarcely studied. While the NLW-GT-01 well was drilled tapping depths of over 4000 meters and encountering temperatures of about 100°C. In contradiction to the pre-drill expectations of having appreciable porosity and permeability values between 10-500mD, the Upper Volpriehausen sandstones in NLW-GT-01 exhibited porosity and permeabilities ranging between 1.4% to 3.9% and ≤0.02mD respectively. The sandstones were highly compacted and severely cemented by dolomite and quartz. These cements blocked all the macropores leaving no visible porosity in the thin sections. Although, the cored interval was extensively fractured the measured permeability values were negligible. This thesis presents the results of an assessment of the factors leading to the deterioration of intrinsic porosity and permeability of Triassic aquifers lying in the Westland and Nederweert regions. In this project, grain-size analysis using core plugs, thin-section study, petrophysical data analysis, and FMI log interpretation were conducted to understand the depositional environment of the Lower Germanic Trias Group precisely the cored sections of the Nederweert Sandstone Member in NDW-01 well and the Volpriehausen sandstones in NLW-GT-01 borehole. Due to the complex tectonic history coupled with locally different paleoenvironments, the current depths of the Triassic deposits in the investigated area did not correlate with the reservoir quality of the adjacent shallower wells. In addition to the local depositional conditions in the basin, the variable precipitation in the source area, and the distance of sediment transport have defined the rock characteristics. The primary grain-textures, such as roundness, sorting, packing, as well as the detrital framework and authigenic minerals, were found to influence the sandstone porosity. The tightness of the reservoir was due to significant mechanical compaction and cementation described by a diagenetic reconstruction explaining the evolution of porosity with depth with a negligible generation of secondary porosity. The deterioration of the reservoir quality is correlatable to the burial history and its resulting consequences, namely mechanical and chemical compaction endured by the rock during periods of basin subsidence and uplift. These analyses have put the deviation of pre-drill results from those that were obtained through post-drill evaluations into perspective. ... Read more

Due to microbial activities, the anaerobic degradation of organic matter happens in the sediments and leads to considerable gas production. Especially for low flow areas gas production is more easily fostered. To prevent the potential problems caused by gas production from the riverine sediments, this study focuses on magnitude of gas formation and its relation with soil properties. Nine locations of known at Port of Hamburg were sampled; for each location the fresh sediment samples were collected at different depths and on different seasons. Samples were stored and transported to several institutes for various analyses, including analysis on sediment standard properties, and on gas production by incubation.

Being part of the BIOMUD project, this study analyzed data from several research institutes. A strong correlation was found between magnitude of gas production and some of the soil properties including content of TOC, TN, ratio of TOC/P, TOC/S, density fractionation, and content of various types of metal elements. A clear relationship was found between magnitude of short-term and long-term gas production, providing possibilities for estimation work on gas formation in the future. The modified Afvalzorg multi-phase model was applied in analyzing gas production on the timeline, which played a key role in describing and predicting gas production in the long-term. The total gas potential of the river sediments at the Port of Hamburg was then predicted as 105.3 mg C/g TOC on average, relating to 10.5% of the organic matter being degraded. By temperature experiment a Q10 value of 2.06 was determined for assessing the sensitivity of gas production to temperature. Gas composition inside the bottles was also measured after four months’ incubation in the temperature experiment, with the results of CH4/CO2 ratio ranged from 0.92 to 1.86 for different temperature conditions. Parts of the results acquired from the experiments mentioned above were also compared with the results from previous studies made by other researches. ... Read more