Appropriate management of coastal flood risk is critical for creating resilient communities. An important part of this is estimating what buildings will become uninhabitable due to a flood event such as a tropical cyclone. To increase the accuracy of these estimations, habitability functions are developed to quantify the relationship between hydrodynamic hazards and the probability of a building becoming uninhabitable following Hurricane Irma. Hazards like maximum flood depths are determined by modeling Hurricane Irma flooding in Delft3D-FM coupled with the wave model SWAN. These modeled hazard levels are then extracted at building locations where Location Based Services (LBS) data provide information on buildings that were uninhabitable following Hurricane Irma. The developed habitability functions provide valuable insights into how different hydrodynamic parameters and regression models perform for estimating building habitability, where maximum unit discharge is generally the best predictor of habitability. Furthermore, we find that while wooden structure habitability is significantly influenced by hazard level, concrete structure habitability is not. These findings provide novel methods for estimating coastal flooding induced building uninhabitability, enhancing how planners can prepare for floods.

Floating offshore wind turbines (FOWTs) are gaining increasing attention as a promising solution for harnessing wind energy in deep-water regions, where traditional bottom-fixed turbines are not feasible. Among the various floating platform designs, semi-submersible platforms have emerged as a leading candidate due to their balance of stability, adaptability, and cost-effectiveness. This paper presents a detailed comparative analysis of two typical types of semi-submersible platforms: the three-column design and the three-column with central column design. The study employs a coupled aero-hydro-mooring simulation system using OpenFOAM to evaluate the hydrodynamic, aerodynamic, and mooring dynamics of both platform configurations. High-fidelity computational fluid dynamics (CFD) simulations, along with a lumped-mass mooring model and the actuator line model (ALM), are employed to capture the coupled fluid-structure interactions and mooring line dynamics. The results reveal significant differences in platform behavior, highlighting the impact of platform geometry on dynamic stability and mooring line response. The additional central column significantly improves pitch stability, reducing the maximum pitch angle by 38.7 % under combined wind and wave loading, indicating enhanced dynamic stability of the additional central column design. Additionally, an economic assessment is provided to evaluate the material costs, installation, and operational expenses for each platform type. The findings suggest that both configurations offer distinct advantages depending on operational and environmental conditions, contributing to the optimization of FOWT platform selection for future offshore wind farms.

Floating Offshore Wind Turbines (FOWTs) operate under complex environmental conditions, where unsteady hydrodynamic forces such as vortex-induced vibrations (VIV) can significantly influence structural response. However, conventional modeling approaches often neglect VIV effects, leading to underestimation of platform motion and hydrodynamic loading. This study incorporates a VIV-induced lift force model into the Morison equation framework within OpenFAST to assess its impact on the dynamic behavior of a spar-type FOWT under steady current conditions. Two simulation cases are compared: one assuming a stationary platform and the other allowing for platform motion through relative velocity coupling. Results show that VIV introduces multi-frequency oscillations in both hydrodynamic force and platform sway response, with amplitudes increasing with current speed. These findings focus on the importance of including VIV effects in hydrodynamic models for accurate prediction of FOWT behavior.

Experiences from Hurricane Katrina and the Tohoku Tsunami illustrate that elevated coastal roads and railroads can be effective countermeasures to coastal flood inundation and damage. In Mississippi, a railroad embankment was reported to have limited the extent of inundation, while an at-grade coastal highway did not. In Tohoku, Japan, elevated coastal highways strongly reduced the extent of the inundation zone. A simple analysis shows that the additional expenditure required to elevate the coastal highway in Mississippi is less than 1% of the direct damages caused in the state by Hurricane Katrina, illustrating the economic benefit of elevating coastal roads as multifunctional flood defences.

As the energy system undergoes a growing reliance on renewable energy while the role of conventional thermal power declines, a utility-scale energy storage system of sufficient capacity may help to ensure supply reliability. Pumped Hydro Storage (PHS) technology dominates utility-scale energy storage and, with its unique advantages, is poised to serve as a mature solution for addressing the inherent intermittency and unpredictability of renewable energy. Past research on PHS has given priority to a substantial elevation difference, which has led to an underestimation of its potential. Therefore, this study focuses on mid-head PHS (30–100 m) and explores its technical feasibility in the Great Lakes region, where large natural basins and suitable topography provide favorable conditions for this type of PHS, aligning with the possible future development of lake-based wind power, indicating potential synergies in power integration and infrastructure co-location. This study identifies the distribution of potential open-loop PHS sites along the Great Lakes shoreline within Michigan and demonstrates that their storage potential far exceeds the storage required for carbon reduction goals in the following decades. The economic analysis also demonstrates that the levelized cost of energy (LCOE) for these storage systems, which meet the demand, is only $30–40/MWh, far lower than other utility-scale energy storage technologies. The study also conducts a sensitivity analysis on the technical parameters of site identification, aiming to address various circumstances regarding preferences and conditions, and demonstrates that the storage in each scenario still far exceeds the required amount.

Hydropower plays a critical role in global renewable energy production, yet its environmental impacts on aquatic ecosystems remain a concern. This study investigates the biological impacts of Shaft-Driven Variable-Speed Contra-Rotating Propeller Reversible Pump Turbines (SDCRRPTs) on fish populations, using Atlantic salmon (Salmo salar) and European eel (anguilla) as experimental models. These species present critical ecological and conservation traits, making them ideal models for assessing hydropower-induced stressors such as rapid decompression, shear, collision, and turbulence. Through Computational Fluid Dynamics (CFD) simulations and the Biological Performance Assessment (BioPA) tool, two SDCRRPT prototypes were evaluated under varying operating conditions. Results indicate that rapid decompression posed minimal risks, while shear stress was the primary cause of mortality for salmon, and collision effects were moderate but species-dependent. The optimized turbine design (Prototype 1) demonstrated improvements in adult fish passage safety compared to the initial design, particularly for eels, yet persistent vulnerabilities highlight the need for further refinements and protective measures, such as physical, mechanical or sensory behavioral barriers combined with bypass systems, to mitigate unavoidable mortality risks during turbine passage. The findings highlight the potential for species-specific design optimization to balance ecological conservation with sustainable energy production. This work underscores the importance of integrating environmental considerations into hydropower technologies to support the EU's decarbonization goals while safeguarding aquatic biodiversity.

The Ike Dike is a concept of coastal barrier system designed to protect the Houston-Galveston area (HGA), which is highly susceptible to flood risks from storm surges. The barrier system has been proposed with different alignments and configurations: movable, permanent, and extended permanent barrier systems. We have evaluated and compared the feasibility of three barrier types as a function of sea level rise (SLR), taking into account the reliability of the movable barrier. We employ the Delft3D Flexible Mesh suite to simulate storm surges in a hydrodynamic model, incorporating pressure and wind velocity fields spatialized by the Holland’s model from synthetic storm tracks. Simulations are driven by a range of SLR projections and synthetic storm tracks, with different barrier types. Probabilistic flood depths are predicted for specific return periods by fitting the 30-year maxima flood depths from the simulations to a probability distribution function. Using the CoreLogic database of residential properties in the HGA and building damage functions, we calculate probabilistic flood damages for each predicted flood depth. This allowed us to quantify flood risk as the expected annual damage, integrated over a range of return periods. Our results indicate that the permanent and extended permanent barrier systems are more effective at mitigating storm surge risk than the movable barrier system. Moreover, the necessity of the extended permanent barrier system becomes more significant as SLR increases.

Land subsidence is a significant issue in many coastal megacities, including Shanghai, where it poses risks to infrastructure and economic stability. Although numerous studies have used SAR datasets to monitor land subsidence in Shanghai, multi-decadal displacement measurements obtained from multi-sensor SAR data remain unavailable. Moreover, the contributions and variations of driving factors behind the evolution of land subsidence remain poorly understood. This study employs multi-sensor SAR fusion method and a Random Forest model, along with Shapley Additive exPlanations (SHAP), to examine subsidence evolution and assess the influence of key drivers over the past 30 years. The results show that severe subsidence has spread from central urban areas to surrounding suburban regions, particularly in the eastern coastal and southern industrial zones in Shanghai. SHAP analysis identified that evapotranspiration, sediment thickness, and groundwater extraction were the dominant factors in the early stage of subsidence, while recent groundwater management and recharge practices have significantly mitigated the subsidence rate. These findings demonstrate the shifting importance of different subsidence factors over time and provide valuable insights for long-term prevention and control measures.

Building resilient urban infrastructure that can anticipate the challenges that come with climate change needs an interdisciplinary approach. Deviating from the paradigm of engineering protection can only be done when the spatial context is integrated. Yet, interdisciplinary cooperation between civil engineering and spatial design, fields with very different cultures and languages, has been protocolized to a multidisciplinary collaboration over time. In order to change this Delft University of Technology incorporated interdisciplinary design into its MSc-level education of civil engineers and spatial designers. Taking challenges in Japan, which have been subject to storm surge and tsunami hazards, Albania, the United States, and Ghana, all of which suffer from pluvial, fluvial, and coastal flooding proved solid learning grounds. The interdisciplinary design projects, organised for students from various disciplines, were set up to learn from and perform the hypothetical redesign and reconstruction of areas in flood plains, aiming to increase disaster resilience and liveability.

The participating students were asked to evaluate their projects to be able to assess the effectiveness of the Tohoku interdisciplinary design method and discuss lessons learned for interdisciplinary projects with engineering and design students. The results show that the interdisciplinary project provides engineering students with more broad and practical experience of the sort that has been lacking in the decades since engineering education came to be dominated by academic researchers rather than practitioners. On the other hand, students in architecture and urbanism viewed this opportunity as a chance to apply their already acquired integrative skills in an interdisciplinary setting.

The structural response of masonry walls during flood events is a critical concern for the flood resilience of (Dutch) buildings, as they typically constitute part of the load-bearing structure. This study investigates the out-of-plane behaviour of a full-scale single-wythe fired-clay-brick masonry wall under out-of-plane hydrostatic pressure and debris impact loads. Experimental tests were conducted on a 2.7 × 2.7 m masonry wall subjected to a vertical pre-compression and simultaneously varying water levels and debris impacts at the Flood Proof Holland facility in Delft, the Netherlands. Results demonstrated that the wall remained within the linear-elastic regime up to a water depth of approximately 90 cm when the interior side was dry. Beyond this threshold, crack initiation and stress redistribution occurred, leading to significant deformation. On the basis of calibrated models, failure was predicted at approximately 150 cm water depth for a fully restrained wall. Debris impact tests showed that soft debris, represented by a floating log, caused negligible additional damage, whereas repeated impacts with a steel cube (hard debris) resulted in progressive cracking and local failure, particularly at higher water levels. Numerical models, including analytical, linear-elastic finite element method (FEM), and non-linear FE approaches, were calibrated using the experimental data. While one-way bending models predicted conservative failure thresholds, two-way, non-linear models accurately captured the wall’s deformation and cracking behaviour, demonstrating the importance of lateral boundary constraints in determining wall capacity and stability. The findings emphasise that traditional masonry walls in Dutch buildings can safely withstand water depths up to 90 cm without significant damage. However, higher water levels or hard debris impacts pose substantial risks, highlighting the need for improved flood resilience strategies. Future work should focus on cavity wall systems, leakage effects, and the behaviour of walls with openings.

Tropical cyclones (TCs) significantly influence coastal sedimentation, geomorphologic features, and morphodynamic processes through strong winds, heavy rains, and storm surges. These effects are particularly pronounced in the east China coastal ocean. However, the impacts of poleward and landward shifts in TC tracks on sedimentology, specifically sediment transport and erosion-deposition processes, remain insufficiently understood. This study utilizes the Delft3D-FM numerical model integrated with TC best track data and field measurements to investigate sediment transport patterns under historical TC tracks and to quantify erosion responses to poleward and landward track shifts. From the historical sediment transport pattern derived from the typical historical TC track, results reveal that sediment in waters shallower than 30 m is highly sensitive to TC activity, with four distinct zones where net sediment transport is sensitive to the change of typical historical TC tracks. Coastal erosion depth changes due to poleward and landward shifts of typical TC tracks during the peak TC intensity period are quantified as 0.24–1.63 cm°N⁻¹ and 0.05–1.06 cm°E⁻¹, respectively. Under global warming scenarios, these values are projected to increase by 2.45%–8.00% and 4.71%–13.33%, respectively. Identifying the coastal areas more susceptible to TC-induced sediment transport and quantitatively assessing the effects of poleward and landward track shifts are important for understanding local TC variability and supporting research on sedimentology during TCs and the future protection of coastal areas.

In the aftermath of Hurricane Ike in 2008 in the United States, the “Ike Dike” was proposed as a coastal barrier system, featuring floodgates, to protect the Houston-Galveston area (HGA) from future storm surges. Given its substantial costs, the feasibility and effectiveness of the Ike Dike have been subjects of investigation. In this study, we evaluated these aspects under both present and future climate conditions by simulating storm surges using a set of models. Delft3D Flexible Mesh Suite was utilized to simulate hydrodynamic and wave motions driven by hurricanes, with wind and pressure fields spatialized by the Holland model. The models were validated against data from Hurricane Ike and were used to simulate synthetic hurricane tracks downscaled from several general circulation models and based on different sea level rise projections, both with and without the Ike Dike. Flood maps for each simulation were generated, and probabilistic flood depths for specific annual exceedance probabilities were predicted using annual maxima flood maps. Building damage curves were applied to residential properties in the HGA to calculate flood damage for each exceedance probability, resulting in estimates of expected annual damage as a measure of quantified flood risk. Our findings indicate that the Ike Dike significantly mitigates storm surge risk in the HGA, demonstrating its feasibility and effectiveness. We also found that the flood risk estimates are sensitive to hurricane intensity, the choice of damage curve, and the properties included in the analysis, suggesting that careful consideration is needed in future studies.

Background: The share of renewable energy feeding the European grid has been growing over the years, even though the intermittency of some renewable energy sources can induce electric grid instability. Energy storage has proven to be an effective way of reducing grid instability. Various solutions for large-scale energy storage are being researched nowadays. This study focusses on the innovative low-head pumped hydro storage (LH PHS) technology, a large-scale energy storage scheme suitable for shallow seas (5 – 30 m depth). Implementation of renewable energy technologies, such as wind farms in Europe, Asia and North America, has faced public opposition which has delayed or even cancelled the implementation of renewable energy projects. Literature about public perception of projects highlights the importance of involving stakeholders from the early stages of project planning. Considering this, the present study aims to collect stakeholder opinions (via an online survey) to determine what is necessary for a smooth implementation of LH PHS in the North Sea, both from technical and policy points of view. Results: Stakeholders from commercial parties, government authorities and local groups recognized the potential of LH PHS as a means to increase the share of renewable energies within the European power grid. Economics, bureaucratic burden, and structural safety have emerged as primary aspects of concern respecting the implementation of LH PHS. The impression of the respondents is that a low-head pumped hydro station would not have negative effects on their organizations. Furthermore, most of the engineering firms participating in the study communicated that their knowledge and resources could be involved in the construction of such an energy storage facility. Conclusion: As identified stakeholder concerns such as economics and structural safety are currently being researched, effective communication of the findings of this research is paramount to keep stakeholders informed of the ongoing progress. Two-way communication between researchers and stakeholders is recommended to enhance public acceptance of future technologies. Furthermore, is it advisable to undertake an examination of the available energy policies relevant to LH PHS.

This study investigates the dynamics of air-water flow and the resulting forces on a broad-crested weir with a vertical face under both ventilated and non-ventilated cavity conditions. The focus is on measured forces and flow characteristics across various upstream water depths and flume outlet heights, categorized by distinct groups based on flow regimes. The experimental setup incorporates measurements of air-water mixture density, air cavity pressure, cavity water depth, and velocity profiles in the recirculation pool downstream of the weir. Results indicate that under supercritical downstream flow conditions, the forces exerted on the weir are directly proportional to the upstream water depth, while the downstream flume depth has a minimal impact. Conversely, in subcritical downstream conditions, the downstream flume depth significantly influences stabilizing forces due to increased cavity water depth. Additionally, pressure profile estimations on the downstream-facing wall of the weir using hydrostatic, Bernoulli, and Navier-Stokes equations show that the hydrostatic assumption is inadequate for estimating pressures and sliding forces in non-ventilated cavities. This study offers crucial insights into air-water flow dynamics in weirs, underscoring the importance of incorporating dynamic factors into weir design and hydraulic modeling.

Emergency responders in coastal cities are anticipated to provide effective evacuation of at-risk populations during the preparedness and response phases of coastal floods due to land-falling storms or cyclones. However, existing contingency plans primarily focus on the evacuation of the general public rather than special arrangement for elderly populations who constitute a large proportion of flood fatalities. Here we present a system-level methodology to elaborate citywide coastal flood evacuation plans for optimal deployment of shelters and effective transfer of elderly people with special needs. We conduct a comparative analysis between Shanghai and New York City, which are both among the most exposed coastal cities to storm-induced flooding but represent two distinct institutional systems of emergency operation. The results show marked disparities in evacuation patterns for elderly residents in the two cities. Storm flood evacuation is more challenging in Shanghai due to insufficient provision of shelter capacity (~230,000). Implementing risk-informed and strategic planning could not only meet the potentially huge demand of vulnerable elderly (~520,000) but also improve the overall efficiency of evacuee transfer by a factor of 3. Our work provides new insights into operational emergency evacuation decisions and informs flood management policy development for major coastal cities globally.

Coastal regions have experienced significant environmental changes and increased vulnerability to floods caused by the combined effect of multiple flood drivers such as storm surge, heavy rainfall and river discharge, i.e., compound floods. Hence, for a sustainable development of coastal cities, it is necessary to understand the spatiotemporal dynamics and future trends of compound flood hazard. While the statistical dependence between flood drivers, i.e., rainfall and storm surges, has been extensively studied, the sensitivity of the inundated areas to the relative timing of a driver's individual peaks is less understood and location dependent. To fill this gap, here we propose a framework combining a statistical dependence model for compound event definition and a hydrodynamic model to assess inundation maps of compound flooding from storm surge and rainfall during typhoon season in Shanghai. First, we determine the severity of the joint design event, i.e., peak surge and precipitation, based on the copula model. Second, we use the same frequency amplification (SFA) method to transform the design event values in hourly time series so that they represent boundary conditions to force hydrodynamic models. Third, we assess the sensitivity of inundation maps to the time lag between storm surge peak and rainfall. Finally, we define flood zones based on the primary flood driver, and we delineate flood zones under the worst compound flood scenario. The study highlights that the temporal delay between storm surge and rainfall plays a pivotal role in shaping the dynamics of flooding events. More specifically, that the peak rainfall occurs 2 h before the peak storm surge would cause the deepest average cumulative inundation depth. At the same time, the results show that in Shanghai surge is the primary flood driver. High storm surge at the eastern part of the city (Wusongkou tidal gauge) propagates upstream in the Huangpu River, resulting in fluvial flooding in Shanghai city center and several surrounding districts. This calls for a better fluvial flooding control system hinging on the backwater effect during high surge in the upper and middle Huangpu River and in the newly added urbanized areas to ensure flood resilience. The proposed framework is useful to evaluate and predict flood hazard in coastal cities, and the results can provide guidance for urban disaster prevention and mitigation.

<p class="p1">The dialogue between Jeremy Bricker and Dicky C. Pelupessy explores the fundamental nature of disasters, questioning the balance between natural forces and human influence while exploring themes of responsibility, risk perception, and preparedness. Drawing from Dicky’s essay <em>Earth, Humankind, and the Haze Disaster</em>, the discussion challenges the idea that the earth itself is vengeful, arguing instead that humans perceive natural events as acts of rage. It highlights humanity’s propensity to take risks and the misconception that disasters are purely natural occurrences. Instead, what we call a disaster is often the consequence of one—the result of human choices and vulnerabilities. For instance, as Dicky’s essay illustrates, in an earthquake, deaths are not caused by the quake itself but by collapsing structures—a failure to account for seismic risks that exceed a building’s capacity.</p><p class="p2">Curated by guest editor Tara Kanj and chief editor Fransje Hooijmeijer, this transcribed dialogue brings together backgrounds in psychology, engineering, and design. Through cases from the Netherlands, Indonesia, and the United States, it highlights the complex interplay between environmental forces and human decisions that shape them.</p>

Marine biofouling is a major concern in the operational performance of submerged floating tunnels (SFTs). The objective of this research is to extend hydrodynamic conditions in experiments and numerically investigate the effects of marine fouling on the hydrodynamic behavior of SFTs, including flow characteristics and forces on the SFT subject to waves. A sensitivity analysis of roughness parameters including different roughness heights and roughness coverage ratios is carried out. Additionally, the hydrodynamic forces of a roughened SFT with a circular shape and a newly designed parametric shape are compared.

Analyzing the spatial-temporal changes in tropical cyclone (TC) tracks in the east China coastal ocean (ECCO) to quantify the magnitude of poleward and landward migration of TCs is of significant importance for coastal disaster mitigation and planning due to its susceptibility to the impacts of TCs. In this study, the TCs that affected the ECCO from 1949 to 2022 are classified into three typical types of tracks using the k-means clustering method, mass moments, and track interpolation based on TC location, shape, and intensity information. Type 1 is a northwestward track, Type 2 is a northwest to northeast-turning track, and Type 3 is a northwest to northeast-turning offshore track. Type 1 tracks mainly make landfall in southern China, while Type 2 predominantly makes landfall in eastern China. Moreover, the proportion of Type 1 decreases while their landfall percentage increases over time, and the proportion of Type 2 tracks is increasing. The probability of TC effects on the eastern and northern parts of the ECCO is increasing, and the boundary where the TC center reaches after landfall is shifting landward. During the period from 1994 to 2022, there has been a significant migration in TC tracks, with the mean centroid of the TCs affecting the ECCO shifting westward by 0.66° in longitude and northward by 1.26° in latitude, which means the magnitude of the poleward shift is about twice that of the landward shift. This migration appears to have been pre-conditioned by a combined influence of a weakening westward steering flow, reduced vertical wind shear, and warmer sea surface temperature Our findings provide valuable insights into the longitudinal and latitudinal migration of TC tracks and have important implications for disaster prevention, mitigation planning, and the adjustment of crucial coastal protection zones in the ECCO and similar regions around the globe.