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Sandy barrier systems are highly dynamic, with the most significant natural morphological changes to these systems occurring during high-energy storm conditions. These systems provide a range of economic and ecosystem benefits and protect inland areas from flooding and storm impacts, but the persistence of many coastal barriers is threatened by storms and sea-level rise (SLR). This study employed observations and modeling to examine recent and potential future influences of storms on a sandy coastal barrier system in Nauset Beach, MA. Drone-derived imagery and digital elevation models (DEMs) of the study area collected throughout the 2023–2024 winter revealed significant alongshore variability in the geomorphic response to storms. Severe, highly localized erosion (i.e., an erosional "hotspot") occurred immediately south of the Nauset Bay spit as the result of a group of storms in December and January. Modeling results demonstrated that the location of the hotspot was largely controlled by the location of a break in a nearshore sandbar system, which induced larger waves and stronger currents that affected the foreshore, backshore and dune. Additionally, model simulations of the December and January storms assuming 0.3 m (1 ft) of SLR showed the system to be relatively resistant to major geomorphic changes in response to an isolated storm event, but more susceptible to significant overwash and breaching in response to consecutive storms. This research suggests that both very strong isolated storm events and sequential moderate storms pose an enhanced risk of major overwash, breaching, and possibly inlet formation today and into the future, raising concern for adjacent communities and resource managers. [ABSTRACT FROM AUTHOR]

Regional sea level rise has been regarded a key factor in understanding of climate change impact to coastal communities. As a vulnerable island to sea level rise and storm surges, the province of Prince Edward Island (PEI) in Canada lacks sufficient long-term island-wide historic record of sea level data. This has become a major challenge for further studies on coastal environments and climate change adaptation. To overcome this limitation, here we reconstruct a long-term hourly sea level dataset using the existing long-term records of limited permanent tide stations and short-term records of widely-distributed temporary stations. With comprehensive statistical analysis and modeling, the historical sea level records furthest between 1911 and 2023 are reconstructed with an hourly time step. This new dataset significantly extends the availability of long-term sea level data along with the shoreline of PEI, which can be used for further studies on coastal change assessment and coastal hazard adaptation in the context of climate change. [ABSTRACT FROM AUTHOR]

Mangrove forests thrive along global tropical coasts, acting as a barrier that protects coastlines against storm surges and as nurseries for an entire food web. They are also known for their high carbon sequestration rates and soil carbon stocks. We introduce a new global mangrove canopy height map generated from TanDEM-X spaceborne elevation measurements collected during the 2011–2013 period with a 12-meter spatial resolution and an accuracy of 2.4 meters (RMSE). Height was calibrated and validated using GEDI mission data and independently verified with airborne Lidar. The tallest mangrove stands reach nearly 60 meters in Colombia and Gabon, and potentially other countries. The map captures a broader range of canopy heights with finer spatial details than other available global products that use optical imagery. This new global mangrove height dataset can aid in evaluating mangrove ecosystem services at local and regional scales, improving our understanding of factors controlling mangrove structure, and supporting conservation, climate mitigation and adaptation strategies. [ABSTRACT FROM AUTHOR]

Salem, Massachusetts, is one of the oldest cities in the United States (1629) and its coastal location on the Atlantic helped create one of the wealthiest cities in America during the late 18th century, but today its coastal location threatens many of its buildings due to sea level rise and increased storm activity. The House of the Seven Gables, a National Historic Landmark District, consists of five important historic buildings, the most famous being The Turner Ingersoll Mansion (1668), more commonly known as The House of the Seven Gables. Considered one of the most important houses in America, it is also one of the most threatened historic buildings due to its location on Salem's harbor. The House of the Seven Gables conducted a two-year study funded by Massachusetts Coastal Zone Management to evaluate the risks posed by climate change. This process included the use of data from groundwater monitoring wells and a tidal gauge installed on-site, along with soil samples and a detailed survey base plan including topography and subsurface infrastructure. The project team then used the Massachusetts Coastal Flood Risk Model (MC-FRM) to assess climate change impacts on the site in 2030, 2050, and 2070, and then created a plan for adaptations that should be implemented before those risks materialize. Strategies for adapting to storm surges, increasing groundwater, and intense surface water runoff were evaluated for their effectiveness and appropriateness for the historic site. The conclusion of the study resulted in a five-phase plan ending in the managed retreat of the historic buildings to higher ground on the existing site. This article goes beyond other research that suggests coastal retreats by demonstrating how to quantitatively evaluate current and future coastal issues with predictive models and how to set viable dates for adaptive solutions and a managed retreat. [ABSTRACT FROM AUTHOR]

Along the southern North Sea coast from the Netherlands to Denmark, human cultivation efforts have created a unique cultural landscape. Since the Middle Ages, these interactions between humans and natural forces have induced major coastal changes. In North Frisia (Germany), storm floods in 1362 AD and 1634 AD turned wide areas of embanked cultural land into tidal flats. Systematic geoarchaeological investigations between Nordstrand and Hallig Südfall comprise coring, trenching, sedimentary, geochemical and microfaunal palaeoenvironmental parameter analyses and radiocarbon dating. Together with geophysical prospection results and archaeological surveys, they give insights into the landscape's development and causes for land losses. Results reveal that fens and bogs dominated from c. 800 BC to 1000 AD but are mostly missing in the stratigraphy. Instead, we found 12th to 14th cent. AD settlement remains directly on top of a pre-800 BC fossil marsh. This hiatus of c. 2000 years combined with local 'Hufen' settlements implies an extensive removal of peat during cultivation eventually resulting in the use of underlying marshland for agricultural purposes. Fifteenth cent. AD tidal flat deposits on top of the cultivated marsh prove that human impact lowered the ground surface below the mean high water of that time, clearly increasing the coastal vulnerability. We consider these intensive human–environment interactions as a decisive trigger for the massive loss of land and establishment of the tidal flats in North Frisia that are currently part of the UNESCO World Heritage "Wadden Sea". [ABSTRACT FROM AUTHOR]

Coastal defense has traditionally relied on hard infrastructures like breakwaters, dykes, and groins to protect harbors, settlements, and beaches from the impacts of longshore drift and storm waves. The prolonged exposure to wave erosion and dynamic loads of different nature can result in damage, deformation, and eventual failure of these infrastructures, entailing severe economic and environmental losses. Periodic post-construction monitoring is crucial to identify shape changes, ensure the structure's stability, and implement maintenance works as required. This paper evaluates the performance and quality of the restitution products obtained from the application of UAV photogrammetry to the longest breakwater in the province of Cádiz, southern Spain. The photogrammetric outputs, an orthomosaic and a Digital Surface Model (DSM), were validated with in situ RTK-GPS measurements, displaying excellent planimetric accuracy (RMSE 0.043 m and 0.023 m in X and Y, respectively) and adequate altimetric accuracy (0.100 m in Z). In addition, the average enveloping surface inferred from the DSM allowed quantification of the deformation of the breakwater and defining of the deformation mechanisms. UAV photogrammetry has proved to be a suitable and efficient technique to complement traditional monitoring surveys and to provide insights into the deformation mechanisms of coastal structures. [ABSTRACT FROM AUTHOR]

Timely and accurate forecasting of storm surges can effectively prevent typhoon storm surges from causing large economic losses and casualties in coastal areas. At present, numerical model forecasting consumes too many resources and takes too long to compute, while neural network forecasting lacks regional data to train regional forecasting models. In this study, we used the DUAL wind model to build typhoon wind fields, and constructed a typhoon database of 75 processes in the northern South China Sea using the coupled Advanced Circulation–Simulating Waves Nearshore (ADCIRC-SWAN) model. Then, a neural network with a Res-U-Net structure was trained using the typhoon database to forecast the typhoon processes in the validation dataset, and an excellent storm surge forecasting effect was achieved in the Pearl River Estuary region. The storm surge forecasting effect of stronger typhoons was improved by adding a branch structure and transfer learning. [ABSTRACT FROM AUTHOR]

Griggs, G.B. and Battalio, B., 2025. Short- and long-term risks of back beach development along the California coast. Journal of Coastal Research, 41(1), 146–179. Charlotte (North Carolina), ISSN 0749-0208. California's beaches in their natural, predevelopment state, like all beaches, would narrow under the impact of winter storm waves and then widen again the following spring and summer. Between the mid-1940s and 1978, the coast of California experienced a cooler and generally calmer Pacific Decadal Oscillation cycle with generally milder and less frequent El Niño events and little coastal storm damage. This was also the period following World War II when California's population grew rapidly, and the landward portions of a number of California's once wide beaches were developed with private homes, commercial establishments, and also public infrastructure during times when these beaches were wide and inviting. In recent decades, however, this development has been repeatedly impacted by short-term extreme events, typically very large waves arriving simultaneously with extreme high tides, often during major El Niño events, which further elevate water levels. Reduction of sand supplies and fluctuations and changes in the wave climate have also been factors in these impacts to shoreline development. Over the long term, rising sea levels will increasingly add to the shoreline challenges facing both private development and public infrastructure. Realistic solutions or responses are limited, however, and include armor and repeated beach nourishment. These are expensive and will only be effective over a few decades at best. Climate change is real, it's now, and it's everywhere. While homeowners understandably are not interested in managed retreat, if not managed, then it will be unmanaged. Each of the state's oceanfront communities where back beach development is being threatened or has been damaged or destroyed needs to identify their most vulnerable assets or development and, using California's most up-to-date assessment of future sea levels and short-term extreme events, plan for the future when maintaining or protecting these areas will no longer be feasible. [ABSTRACT FROM AUTHOR]

Compound mitigation systems, integrations of natural and engineering structures against the high inundating current from tsunamis or storm surges, have garnered significant interest among researchers, especially following the Tohoku earthquake and tsunami in 2011. Understanding the complex flow phenomena is essential for the resilience of the mitigation structures and effective energy reduction. This study conducted a flume experiment to clarify flow characteristics and fluid force dissipation in a compound defense system. Vegetation models (V) with different porosities (Φ) were placed at three different positions downstream of an embankment model (E). A single-layer emergent vegetation model was considered, and a short-layer vegetation with several values of Φ was incorporated to increase its density (decreased Φ). Depending on Φ and the spacing (S) between the E and V, hydraulic jumps occurred in the physical system. The findings demonstrated that a rise in S allowed a hydraulic jump to develop inside the system and contributed to reducing the fluid force in front and downstream of V. Due to the reduced porosity of the double-layer vegetation, the hydraulic jump moved upstream and terminated within the system, resulting in a uniform water surface upstream of V and downstream of the system. As a result, the fluid force in front of and behind V reduced remarkably. [ABSTRACT FROM AUTHOR]

Tropical cyclones (TCs) are natural hazards causing extensive damage to society, infrastructure, and the natural environment. Due to the multi-hazardous nature of TCs, comprehensive risk assessments are essential to understanding how to better prepare for potential impacts. This study develops an integrated methodology for TC multi-hazard risk assessment that utilises the following individual assessments of key TC risk components: a variable enhanced bathtub model (VeBTM) for storm surge-driven hazards, a random forest (RF) machine learning model for rainfall-induced flooding, and indicator-based indices for exposure and vulnerability assessments. To evaluate the methodology, the regions affected by TC Debbie (2017) for Queensland and TC Winston (2016) for Fiji's main island of Viti Levu were used as proof-of-concept case studies. The results showed that areas with the highest risk of TC impacts were close to waterbodies, such as at the coastline and along riverine areas. For the Queensland study region, coastal populated areas showed levels of "high", "very high", and "extreme" risk, specifically in Bowen and East Mackay, driven by the social and infrastructural domains of TC risk components. For Viti Levu, areas classified with an "extreme" risk to TCs are primarily areas that experienced coastal inundation, with Lautoka and Vuda found to be especially at risk to TCs. Additionally, the Fiji case study was validated using post-disaster damage data, and a statistically significant correlation of 0.40 between TC Winston-attributed damage and each tikina's overall risk was identified. Ultimately, this study serves as a prospective framework for assessing TC risk, capable of producing results that can assist decision-makers in developing targeted TC risk management and resilience strategies for disaster risk reduction. [ABSTRACT FROM AUTHOR]

Sedimentary records of event deposits are crucial for regional natural disaster risk assessments and hazard history reconstructions. After Super Typhoon Haiyan passed through the South China Sea in 2013, five gravity cores were collected along the typhoon path in the southern South China Sea basin (>3800 mbsl). The results showed that Super Typhoon Haiyan deposits with clear graded bedding are preserved at the top of all cores. The thickness of the typhoon layers ranges from 20 to 240 cm and is related to changes in typhoon intensity. The lack of river-connected submarine canyon systems limited the transportation of terrestrial sediments from land to sea. Super Typhoon Haiyan-induced large surface waves played an important role in carrying suspended sediment from the Philippines. The Mn-rich layers at the bottom of the typhoon layers may be related to the soil and rock composition of the Palawan region, which experienced tsunami-like storm surges caused by Super Typhoon Haiyan. These Mn-rich layers may serve as a proxy for sediment export from large-scale extreme terrigenous events. This study provides the first sedimentary record of extreme typhoon events in the deep ocean, which may shed light on reconstructing regional hazard history. [ABSTRACT FROM AUTHOR]

This study employs the Delft3D numerical model to elucidate nonlinear interactions in velocity dynamics across four key marine regions during typhoon-induced storm surges (Typhoon In-fa, No. 2106). To address gaps in understanding how typhoon winds drive storm surges, this study aims to analyze the relative contributions of bottom friction, wind stress, and convective terms to storm surge dynamics, providing insights for predictive modeling and marine hazard mitigation. Introducing a novel metric, the "Flow Velocity Nonlinear Coupling Proportion" ("FVNCP", abbreviated as "NCP"), this research quantifies the interactive effects of storm surge flow velocity by dissecting the contributions of bottom friction, wind stress, and the convective term. Through decision tree modeling, wind stress emerges as the primary driver of NCP in open sea and sheltered areas, with peak values reaching 1.50 × 10−4 and 2.14 × 10−4 m/s2, respectively. In contrast, the convective term dominates the strait and bypassing regions, exhibiting maximum impacts of 3.21 × 10−4 and 2.94 × 10−4 m/s2, while bottom friction's influence is consistently minor across all regions. Wind stress contributes the most to NCP in open waters, at an average of 48.28%, while the convective term exerts a comparable 38.85% effect. In confined areas like the strait and bypassing regions, the convective term accounts for 40–44% of the NCP, with wind stress contributing 32–39%. The role of bottom friction is the least among the three factors though its impact intensifies in shallower zones. These findings offer critical insights for advancing predictive models and informing strategies to mitigate typhoon-driven marine hazards. [ABSTRACT FROM AUTHOR]

This study utilizes historical monitoring data from the Xu Fan small watershed spanning 1962 to 2021 and employs the K-means clustering algorithm to classify extreme rainfall events into three distinct categories: short-duration high-intensity rainfall, sustained moderate-intensity rainfall, and long-duration heavy rainfall. Through the application of the Random Forest model, key factors influencing flood characteristics are identified, including total rainfall, maximum rainfall intensity, the timing of maximum intensity, and rainfall duration. The comparative analysis of data before and after 1990 highlights that climate change has led to increased maximum rainfall intensity, reduced rainfall duration, and shifts in the temporal distribution of rainfall, thereby exerting a significant influence on the flood generation process. [ABSTRACT FROM AUTHOR]

Coastal zones, critical for their ecological and economic significance, are increasingly vulnerable to storm surges, sea-level rise, and land subsidence. Traditional defense mechanisms, such as dikes and seawalls, are often costly and environmentally taxing. This research highlights how beach and dune systems, key components of coastal protection in the Baltic Sea region, evolve following sand nourishment. Dunes, sustained by periodic sand replenishments, play a critical role in shielding the coast from storm surges, high water levels, and erosion. High-resolution data from Unmanned Aerial Vehicle surveys, alongside terrestrial field observations, provide insights into the morphological changes post-nourishment, including the formation and dynamics of sandbars. Additionally, we demonstrate how UAV photogrammetry can achieve significantly improved change detection through advanced co-alignment techniques, resulting in enhanced precision and reliability of the data. The study underscores the importance of dunes and sandbars in mitigating erosion and advocates for their continued inclusion in coastal protection strategies. The results emphasize the need for long-term monitoring and adaptive management to optimize nourishment effectiveness, supporting sustainable coastal development and resilience against future challenges. [ABSTRACT FROM AUTHOR]

Against the backdrop of global warming and rising sea levels, storm surge disasters occur frequently, often forming complex chains of events that lead to severe crises. However, systematic research on storm surge disaster chains is scarce. To characterize these chains, this research proposes a storm surge disaster chain analysis system based on complex networks and Bayesian networks. The system consists of three modules: evaluation, prediction, and measurement. The evaluation module uses a complex network model to quantitatively analyze the vulnerability, key nodes, and critical transmission paths of the disaster chain complex network. The prediction module establishes a Bayesian network-based model to forecast the complex network evolution process, forecasting the occurrence probability and loss scenarios of the disaster events. The measurement module measures and calculates the chain effect based on the dependence relationship and loss degree of the disaster event loss scenario. The results elucidate that most key nodes are primary and secondary disasters such as seawater flooding, flooding, dam damage, rainstorm, and house damage. Meanwhile, edges such as the sea wave–seawater flooding and house damage–human casualties have a critical impact on the storm surge disaster chain complex network. Key evolutionary paths such as strong winds–human casualties and over-warning tide level–social influence need to be focused on. Disaster reduction strategies such as maintaining dams, reinforcing houses, and removing disaster-bearing body can effectively break the chain and mitigate disasters. This research has a reference value for the scientific understanding of storm surge disaster chains and can serve as a scientific basis for comprehensive disaster reduction, disaster preparedness, and disaster relief. [ABSTRACT FROM AUTHOR]

Fjords are known for their biodiversity and abundant aquaculture resources. However, climate and anthropogenic pressures are altering fjord biological, physical, and chemical processes that will undoubtedly change the ecosystem as a whole. To investigate the impact of climate change on fjord functioning, this study examines the impacts of drought conditions on the physical dynamics and salinity variations in a fjord known for its bolstering aquaculture industry in Northern Chilean Patagonia, the Reloncaví Fjord (41.5° S). Using a high-resolution hydrodynamic model and the Total Exchange Flow (TEF) framework, we analyzed the impacts of river discharge, tides, and wind during a dry year (2016) and a typical year (2018). In 2016, reduced freshwater input decreased exchange flow and increased salinity compared to 2018. In 2018, river discharge dominated TEF variability (74%), while tides and wind contributed 17% and 9%, respectively. In summer 2016, tidal and wind influences rose to 21% and 16%, highlighting their role under low freshwater conditions. Increased wind facilitated destratification, mixing high-salinity subsurface waters with fresh surface layers, affecting ecosystem dynamics. From these results we developed a method to predict long-term stratification variability (1980–2021), identifying critical ecological shifts. Logistic regression models showed significant links between stratification levels and harmful algal blooms (HABs) of Pseudchatonella spp. and Alexandrium catenella. Lower stratification was linked to higher Pseudchatonella spp. HABs in summer, while higher stratification correlated with Alexandrium catenella blooms in spring, tied to increased river discharge. These results suggest that severe HAB events in Northern Patagonia may become more frequent with climate change, underscoring the need to consider local environmental dynamics and stratification in HAB studies. [ABSTRACT FROM AUTHOR]

South Asia, the home of 23% population of the world, is adversely affected by climate change, global warming, floods, hurricanes and heat waves. Pakistan, as a member country of South Asia, is the 5th country in the world which is most vulnerable to climatic changes. The country has faced many challenges including deaths of 9989 individuals, economic loss of worth $ 3.8 billion, and more than 150 unexpected weathers during last two decades. Global climate index also mentioned that Pakistan's vulnerability to climate change will rise even further in coming years. Pollution from agriculture sector is believed to be the largest significant contributor for this situation that accounts for 41% of total pollution. The above stats paint a bleak picture of future for the country and calls for emergency measures, to be taken on war like footings, if future climatic impact is to be minimized. With this background, we argue that climate smart agriculture (CSA) may be a strategic option that can help the country for improving agricultural productivity and income, as well as building resilience to climate change and environmental management. The present research study highlights the importance of CSA in the context of an emerging economy like Pakistan and suggests some strategic considerations for policy makers in order to improve the current environmental situation, mainly caused by widespread pollution in the country. Highlights: This study highlights CSA as a key solution for boosting agriculture and climate resilience in Pakistan. This study links CSA adoption in Pakistan to global climate goals and the UN Sustainable Development Goals. This study provides short- and long-term strategies for CSA adoption to guide policymakers on key actions. [ABSTRACT FROM AUTHOR]

Introduction: This study investigates non-linear surges and extreme wind-wave patterns in Port Phillip Bay (PPB), Victoria, Australia, under both current and projected mean sea level (MSL) scenarios. The research aims to understand the potential impacts of increasing MSL on extreme surges and wind-waves, utilising a combined wave-circulation modelling system (SCHISM-WWMIII). Methods: This validated coupled model was employed to simulate 32 years of hindcasts (1990-2022) applied to five distinct MSL scenarios: existing, 0.5 m, 0.8 m, 1.1 m, and 1.4 m. Modelled data were extracted from 24 different stations in the bay at a depth of 2 m to analyse the impacts of increasing MSL on extreme surges and wind-waves. Results: Under the current scenario, the results indicate that both surges and wave patterns are significantly influenced by seasonal wind patterns. In the context of rising MSL, the research reveals that while surges exhibit a degree of resilience to changes in MSL, the wave field is more vulnerable to such variations. The non-linear response of the wave field to increasing MSL further complicates the scenario. For instance, there is an unequal response in the median of the annual maximum significant wave height (Hs) corresponding to the rising MSL from 0 m to 0.5 m and from 0.5 m to 0.8 m, which is expected due to wave breaking triggered by changes in water depth. Specifically, the median annual maximum Hs at 12 locations remains unchanged when MSL increases from 0 m to 0.5 m. However, increasing MSL from 0.5 m to 0.8 m increases the median annual maximum Hs by up to 0.36 m, accounting for 70% of the total increase in the median annual maximum Hs when MSL rises from 0 m to 1.4 m at the same locations. Discussion: The study found that intensification in the median of annual maximum Hs occurs only in locations where the values exceed 1.0 m. This suggests that areas with higher extreme Hs values are more prone to experiencing significant variations. In contrast, stations with a median annual maximum Hs below the 1.0 m threshold exhibit only minor increases in the annual maximum Hs. These findings highlight the complex and non-linear nature of the wave field's response to rising MSL and emphasise the importance of considering local conditions when assessing the impacts of sea level rise on coastal regions. [ABSTRACT FROM AUTHOR]

The editorial in "Frontiers in Marine Science" pays tribute to the late Dr. Saleemul Huq, a renowned advocate for climate justice and adaptation, particularly in vulnerable regions like Bangladesh. Dr. Huq's work focused on locally led adaptation efforts, community-based adaptation, and establishing funds to support developing nations in addressing climate change impacts. The editorial also highlights research on resilience and adaptation strategies to sea-level rise impacts, emphasizing the importance of balancing both approaches to safeguard against risks effectively. The text underscores the need for education, trust, and community engagement to ensure sustainable solutions and a just transition in the face of climate change challenges. [Extracted from the article]

German coastal areas are often protected from flood events by a primary sea dike line of more than 1,200 km. Many transition areas, such as the change of surface covering materials and other dike elements such as stairs, fences, or ramps at intermittent locations, characterize the stretch of this sea dike line. During storm surges and wave overtopping, the onset of damage, especially dike cover erosion, is often initiated at these transitions due to locally disturbed flow characteristics, increased loads, and reduced strength at the interface. An in-depth understanding of damage initiation and building stock conditions along coastlines as a foundational element of a flood cycle is essential in order to accurately assess existing defense structures, both deterministically and probabilistically. Thus, the present study is motivated to examine the variety of transition areas on the sea dikes along the German coasts, for further assessment of probability of their damage and failure. A novel remote inventory was elaborated manually, based on satellite images for a length of 998 km along the German North Sea and 123 km along the German Baltic Sea coast and estuaries, and it shows the spatial distribution and frequency of such transitions on sea dikes. During additional on-site investigations at different locations at the coast, detailed information about design variants of dike elements as well as damage to transitions were recorded and reported systematically. The results of the on-site investigations allow the development of a damage catalog in relation to transitions and the validation and verification of the remote inventory. By categorizing and spatially analyzing a large number of transitions (n ≈ 18,300) and damages along the coast, particularly vulnerable transitions and hot spots of loading can be further investigated regarding the flow-structure-soil interaction. Through this, structural layouts and material combinations can be optimized for the design of sea dikes. [ABSTRACT FROM AUTHOR]

The response of beach sedimentary geomorphology to consecutive storms is a complex process, especially for beaches surrounding an island. Variations in coastal sedimentary landforms, dynamic environments and levels of development and utilization lead to non-uniformity in storm response, which may become more pronounced when influenced by continuous storms. This study focuses on the beaches around Weizhou Island to investigate this non-uniformity. Based on the topographic, surface sediment and hydrodynamic data collected on site before and after the consecutive typhoons (Typhoons Lionrock and Kompasu), the study examines the characteristics of beach geomorphology and surface sediment. The results show significant differences in the geomorphological responses between the four zones along the island. On the plane, the deposition degree of Zone I beach gradually weakened from west to east, and most areas of Zone III beach appeared in an alternating state of erosion and deposition. The beaches of Zone II and Zone IV showed the characteristics of dramatic changes in the northern and central beaches and relatively stable in the southern beaches. On the profile, the beach deformation area mainly occurs in the middle and upper parts of foreshore and berm. The response intensity of beaches in zone I is the weakest, the response intensity of beaches in zone III is the most intense, and the response intensity of beaches in zone II and zone IV is relatively close. However, the performance of beach sediments in different regions before and after continuous typhoons is less different. Except that the beach sediments in Zone I were mainly refined, the beach sediments in other zones of Weizhou Island were relatively coarse, and the sediments in the middle and upper parts of the foreshore were the coarsest, with the sorting being the worst. The different combinations of incident waves and storm surges during the typhoons are the primary factors that lead to various geomorphological responses in different zones. The antecedent beach status, distributions of rock and coral reefs, and anthropogenic activities further exacerbate these differences. This work can provide reference for island beach protection and management. [ABSTRACT FROM AUTHOR]

The document "Advances in Air–Sea Interactions, Climate Variability, and Predictability" explores the complex interactions between the atmosphere and ocean, impacting weather and climate variability. Recent research highlights advancements in observational technology and modeling techniques, improving predictions of climate variability and extreme weather events. Articles within the document delve into topics such as the predictability of climate patterns like the North Atlantic Oscillation, drivers of extreme rainfall, Antarctic sea-ice dynamics, and the impact of wave processes on evaporation ducts. Despite progress, challenges remain in understanding air–sea interactions, emphasizing the need for enhanced observational tools, model resolution, and integration of AI techniques to advance climate research. [Extracted from the article]

In this study, a new articulated concrete armor unit named Couple-Lock, which can be enlarged in size to cope with high waves, is easy to secure binding force between units, and can be applied to various field conditions, was developed. The Couple-Lock consists of two symmetrical blocks. One symmetrical block has four legs installed in all directions on one end of the body. Since two left-right symmetrical blocks are connected with a wire rope and behave, a pair of blocks can be treated as a single block and enabling large size to cope with high waves. Also, the Couple-Lock responds flexibly to topographical changes. In order to examine the hydraulic performance and stability of the developed armor unit, a hydraulic model experiment was conducted. As a result, the average reflection coefficients of ordinary wave and storm wave conditions were calculated as 0.433 and 0.533, respectively. The average transmission coefficients under ordinary wave and storm wave conditions were calculated as 0.046 and 0.147, respectively. Among the 62 storm wave conditions, wave overtopping occurred in 50 storm waves. The stability factor of the Couple-Lock was calculated to be about 18, which is twice of the stability factor of the tetrapod. [ABSTRACT FROM AUTHOR]

Due to increasing coastal flooding and erosion in changing climate and rising sea level, there is a growing need for coastal protection and ecological restoration. Artificial sandbars have become popular green coastal infrastructure to protect coasts from these natural hazards. To assess the effect of an artificial sandbar on wave transformation over a beach under normal and storm wave conditions, a high-resolution non-hydrostatic model based on XBeach is established at the laboratory scale. Under normal wave conditions, wave energy is mainly concentrated in short wave frequency bands. The wave setup is negligible on the shoreface but becomes more significant over the beach face, and wave nonlinearity increases with decreasing water depth. The artificial sandbar reduces the wave setup by 22% and causes considerable changes in wave skewness, wave asymmetry, and flow velocity. Under storm wave conditions, as the incident wave height increases, the wave energy in the long wave frequency bands rises, while it decreases in the short wave frequency bands. The wave dissipation coefficient of an artificial sandbar increases first and then decreases with increasing incident wave height, and the opposite is true with the transmission coefficient. It features that the effect of an artificial sandbar on wave energy dissipation strengthens first and then weakens with increasing incident wave height. Additionally, an empirical formula for the wave runup was proposed based on the model results of the wave runup for storm wave conditions. The study reveals the complex processes of wave–structure–coast interactions and provides scientific evidence for the design of an artificial sandbar in beach nourishment projects. [ABSTRACT FROM AUTHOR]

Copyright of Al-Mustansiriyah Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of LHB: Hydroscience Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Human activities and climate change have significantly influenced the water cycle, impacting flood risks and water security. This study centers on the Jing River Basin in the Chinese Loess Plateau, analyzing hydrological patterns and flood progression using the HEC-HMS model under changing conditions. The findings indicate that climate change substantially affects flood predictions, increasing peak flows and volumes by up to 10.9% and 11.1%, respectively. It is essential to recognize that traditional flood models may underestimate the risks posed by these changes, emphasizing the necessity for updated methods incorporating climatic and human factors. Changes in land use, such as the expansion of grasslands and forests, have reduced peak discharges and flood volumes. Consequently, the combined impacts of climate and land use changes have intensified flood frequencies, necessitating updated strategies to manage risks effectively. The dynamics of flooding are significantly impacted by changes in climate and land use, particularly in minor floods that occur frequently, highlighting the influence of climate change on flooding trends. Within the Jing River Basin, hydrological patterns have been shaped by both climatic variations and human activities, leading to an increase in extreme hydrological events and concerns regarding water security. Using the HEC-HMS model, this study examines the hydrology of the Jing River Basin, focusing on the design of storm events and analyzing various flood characteristics under different scenarios. Climate change has resulted in higher peak discharges and volume surges ranging from 6.3% to 10.9%, while shifts in land use, such as decreases in farmland and the expansion of grasslands, have caused declines ranging from 7.2% to 4.7% in peak flows and volumes. The combined effects of climate variation and land utilization have complex implications for flood patterns, with milder to moderate floods showing a more significant impact and shorter return periods facing increased consequences. These findings underscore the interconnected nature of climate change, land use, and flooding dynamics in the Jing River Basin, highlighting the need for comprehensive strategies to address these challenges and ensure sustainable water management in the region. [ABSTRACT FROM AUTHOR]

Sand dunes protect the most important economic and ecologically critical landscapes from coastal hazards (storms and high-tide flooding). The characteristics of the dune affect their protective ability. This paper qualitatively and quantitatively assesses the relationships between pre- and post-storm conditions for vegetation and the morphology of an incipient dune system along the South Carolina coast. Field-based dune vegetation and morphology measurements were obtained before and after tropical storm Dorian (2019). Vegetation is assessed with respect to distribution and functional type, and subgroups are introduced to categorize land cover transitions. At the quadrat scale (0.2 m2) following the storm, there was a shift from stabilizer to builder, a decrease of sand (2%), and the vegetation remained consistent at around 61% of the land cover. Transect-level analysis (0.2 m × 1.0 m) revealed distinct variability concerning post-storm morphology change in the extreme study site extents. Dorian resulted in approximately 10% volumetric loss over the entire study site (101 m2). This study demonstrated changes to a dune system following a tropical storm with wind as the dominant forcing factor. This study revealed that vegetation presence is not broadly correlated with reduced levels of post-storm erosion. [ABSTRACT FROM AUTHOR]

Previous research showed that a tsunami similar to the 1755 event would inundate Caxias' low-ground areas in Oeiras municipality, Portugal. However, the streets of downtown Caxias were not well reproduced, which is a limitation of the area's mitigation strategies and evacuation plan. For these reasons, new Lidar data were used for the first time in Portugal. The new local topography data allowed the construction of a more accurate DEM, which was used in the tsunami numerical model to update and improve the inundation results. As a complement, a field survey was conducted in several locations to assess coastal features and protection. The numerical model results show that low-ground areas up to 6 m in height were inundated by the tsunami, including the residential area, the road, and the railway. To stop the tsunami waves from inundating these areas, it is proposed that the construction of more sea walls up to 7 m in height and a third bridge over the Barcarena Stream, only for pedestrians, ranging from 5 to 7 m in height, which will serve as a gate for the incoming tsunami waves. These coastal protections should be part of the strategy to mitigate coastal overtopping (winter storm surges and tsunamis) not only in Caxias but also in other coastal zones. [ABSTRACT FROM AUTHOR]

Beach profiles are constantly changing due to external ocean forces. Estimating these changes is crucial to understanding and addressing coastal erosion issues, such as shoreline advance and retreat. To estimate beach profile changes, obtaining long-term, high-resolution spatiotemporal beach profile data is essential. However, due to the limited availability of beach profile survey data both on land and underwater along the coast, generating continuous, high-resolution spatiotemporal beach profile data over extended periods is a critical technological challenge. Therefore, we herein developed a long short-term memory-based encoder–decoder network for effective spatiotemporal representation learning to estimate beach profile responses on temporal scales from weeks to months from coastal hydrodynamics. The proposed approach was applied to 12 transects from seven beaches located in three different littoral systems on the east coast of the Korean Peninsula, where coastal erosion problems are severe. The performance of the proposed method demonstrated improved results compared with a recent study that performed the same beach profile estimation task, with an average root mean square error of 0.50 m. Moreover, most of the results exhibited a reasonably accurate morphological shape of the estimated beach profile. However, instances where the results exceed the average error are attributed to extreme beach morphological changes caused by storm waves such as typhoons. [ABSTRACT FROM AUTHOR]

Storm waves and rising sea levels pose significant threats to low-lying coastal areas, particularly sandy beaches, which are especially vulnerable. The research on the long-time-scale changes in sandy coasts, especially the identification of tipping points in the shoreline-retreat rate, is limited. Vung Tau beach, characterized by its low terrain and rapid tourism-driven economic growth, was selected as a typical study area to quantify the shoreline retreat throughout the 21st century under various sea-level rise (SLR) scenarios, and to identify the existence of tipping points by investigating the projected annual change in shoreline retreat (m/yr). This study employs the Probabilistic Coastline Recession (PCR) model, a physics-based tool specifically designed for long-term coastline change assessments. The results indicate that shoreline retreat accelerates over time, particularly after a tipping point is reached around 2050 in the SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios. Under the SSP5-8.5 scenario, the median retreat distance is projected to increase from 19 m in 2050 to 89 m by 2100, nearly a fourfold rise. In comparison, the retreat distances are smaller under the SSP1-2.6 and SSP2-4.5 scenarios, but the same accelerating trend is observed beyond 2050. These findings highlight the growing risks associated with sea-level rise, especially the rapid increase in exceedance probabilities for retreat distances by the end of the century. By 2100, the probability of losing the entire beach at Vung Tau is projected to be 22% under SSP5-8.5. The approach of identifying tipping points based on the PCR model presented here can be applied to other sandy coastal regions, providing critical references for timely planning and the implementation of adaptation measures. [ABSTRACT FROM AUTHOR]

Introduction: Seagrass sediments are important 'blue carbon' reservoirs which store climatically significant quantities of organic carbon (Corg) at the global scale. Seagrass meadows that overly these sediments also provide a range of critical ecosystem services including shoreline stabilization, storm surge protection, and fisheries nursery grounds. However, the controls over accumulation and the sources of organic C to these sediments beds are highly variable and poorly understood with the relative importance of hydrodynamic setting, species composition and canopy density being unclear. Methods: Here we address these questions using the first observation-based estimates of Corg stocks and provenance on Turneffe Atoll, Belize, made via remotely-sensed habitat extent, local Corg data and isotopic data. Sedimentary Corg was highest in sediments underlying the most sheltered meadows and decreased with increasing exposure to wind and wave energy with the seagrass meadows in the central lagoon containing an extensive deposit of mangrove derived organic carbon, stabilized and protected by the overlying seagrass meadow. Results: The influence of species composition appeared weak with the ubiquitous species T. testudinum occurring across a wide range of hydrodynamic regimes ranging from the most sheltered to the most energetic and being associated with a wide range of sedimentary organic C concentrations. Importantly from the perspective of remote sensing, org C concentrations were unrelated to canopy density. We hypothesize that this decoupling of organic C concentration from seagrass canopy cover reflects a much longer timescale for carbon storage in the sediments than the lifespan of the seagrass plants themselves and/or a substantial non seagrass derived organic C burden in seagrass sediments. Overall, we conservatively estimate that the top 30cm of sediments underlying the seagrass meadows overlying carbonate sediments on the atoll exterior store 0.58 x 106 Mg Corg, most of which is seagrass-derived, whilst the sediments underlying the meadows within the central lagoon store an additional 1.28 x 106 Mg Corg. When the maximum possible extent of seagrass is considered, this estimate increases to 3.54 x 106 Mg Corg. Substantial Corg stocks extending >1m depth were observed across all sites, and so these inventories are considered conservative. Discussion: A preliminary 'cost of loss' for sedimentary Corg in the top 30 cm of Turneffe Atoll's seagrass meadows, based on a carbon trading value of €60 tCO2 (eq), is estimated at €42 million for the outer atoll, increasing to €136 million when the mangrove-derived sediments of the central atoll are considered and €260 million when turbid areas are assumed to contain seagrass. [ABSTRACT FROM AUTHOR]

Low and high-latitude ionospheric scintillations are well-documented, but data on lower mid-latitude scintillations are scarce. Moreover, there is limited public reporting for the Chengdu station, which makes the data for the consecutive three years particularly valuable. This paper analyzes three years of ionospheric scintillation data from Chengdu and compares it with Chongqing. GNSS receivers in Chengdu (104.07°E, 30.67°N) and Chongqing (106.55°E, 29.57°N) recorded the data from 2018 to 2020. A custom data processing program for GPS/BDS/Galileo monitors was used. Results show diurnal and seasonal variations in the occurrence rate (OR) of scintillation events, with higher OR in spring and autumn, predominantly at night. There is a positive correlation between the annual OR of weak, moderate, and strong scintillations. Besides, moderate scintillation and strong scintillation events mainly occur at azimuth angles of 30°-90°, 150°-210°, and 300°-330° due to the aspect sensitivity of ionospheric irregularities. Solar activity, mesospheric winds, and ionospheric tides also influence scintillations. Notably, intense events were observed in May 2018(a year of low solar activity) due to post-sunset occurrences influenced by neutral wind and ionospheric tides, suggesting that in addition to solar radiation, neutral wind and ionospheric tides may serve as substantial driving mechanisms for ionospheric scintillation. This study provides a reference for the construction of a scintillation prediction in lower mid-latitudes. [ABSTRACT FROM AUTHOR]

High Frequency Radar (HFR) has gained world-wide use as a land based remote sensing technology capable of measuring ocean surface currents and ocean waves at ranges up to 200 km or more. Regional HFR networks support a variety of services including support for search and rescue, marine spill response, and resource management operations. HFR data is useful for validation and calibration of hydrodynamic models that are used to forecast storm-surge, combined flooding and surface currents. Long-term time series data are also needed to assess changes in ocean/estuary currents in response to changes in climate, hydrology, and major coastal infrastructure. The main objective of this paper is to document the site selection process applied for two HFR networks, commissioned in Galveston Bay and Sabine Lake in Southeast Texas. The general process involved several steps including: identify sites meeting technical requirements and constraints; site access negotiation, permitting, station design, station commissioning, network operation and maintenance. To some degree, these processes could be considered sequential; however, in practice intermediate steps were essentially iterative in nature. [ABSTRACT FROM AUTHOR]

While tidal marshes are valued for their ability to reduce the impact of storm waves on shores, there is still more limited understanding of how storm waves impact the integrity of tidal marshes, particularly in mudflat‐marsh transition zones with patchy vegetation cover. This study aims to investigate changes in hydrodynamics, sediment bed elevation, and patchy vegetation cover along the sea‐to‐land elevation gradient in response to super typhoon IN‐FA, making landfall in 2021 in a mudflat‐marsh transition zone of the Yangtze Estuary (China). Utilizing in‐situ measurements and drone surveys, our results show: (1) A landward decrease in storm‐induced wave energy, flow velocities, turbulence, and erosion across a 200‐m mudflat‐marsh transition zone; (2) Elevation‐dependent spatial reconfiguration of marsh vegetation patches in response to the storm; (3) Different marsh response below and above an elevation threshold where a shift between marsh gain and marsh loss occurred. The observed landward decrease in storm‐induced marsh loss is attributed to a trade‐off between reduced disturbances due to landward increasing friction from the sediment bed and vegetation, and the landward increasing capacity of the vegetation to cope with disturbances. Our findings provide new insights relevant to the response of marsh systems to storms, and highlight the importance of the gradual and adequately wide sea‐to‐land gradient in delivering marsh resistance to extreme events. [ABSTRACT FROM AUTHOR]

A real-time forecast model of surface hydrodynamics in Lake Ontario (Coastlines-LO) was developed to automatically predict storm surges and surface waves. The system uses a dynamically coupled Delft3D–SWAN model with a structured grid to generate 48 h predictions for the lake that are updated every 6 h. The lake surface is forced with meteorological data from the High Resolution Deterministic Prediction System (HRDPS). The forecast model has been running since May 2021, capturing a wide variety of storm conditions. Good agreement between observations and modelled results is achieved, with root mean squared errors (RMSEs) for water levels and waves under 0.02 and 0.26 m, respectively. During storm events, the magnitude and timing of storm surges are accurately predicted at nine monitoring stations (RMSE <0.05 m), with model accuracy either improving or remaining consistent with decreasing forecast length. Forecast significant wave heights agree with observed data (1 %–12 % relative error for peak wave heights) at four wave buoys in the lake. Coastlines-LO forecasts for storm surge prediction for two consecutive storm events were compared to those from the Great Lakes Coastal Forecasting System (GLCFS) to further evaluate model performance. Both systems achieved comparable results with average RMSEs of 0.02 m. Coastlines-LO is an open-source wrapper code driven by open data and has relatively low computational requirements compared to GLCFS, making this approach suitable for forecasting marine conditions in other coastal regions. [ABSTRACT FROM AUTHOR]

A well-validated storm surge numerical model is crucial, offering precise coastal hazard information and serving as a basis for extensive databases and advanced data-driven algorithms. However, selecting the best model setup based solely on common error indicators like the root-mean-square error (RMSE) or Pearson correlation does not always yield optimal results. To illustrate this, we conducted 34-year high-resolution simulations for storm surge under barotropic (BT) and baroclinic (BC) configurations using atmospheric data from ERA5 and a high-resolution downscaling of the Climate Forecast System Reanalysis (CFSR) developed by the University of Genoa (UniGe). We combined forcing and configurations to produce three datasets: (1) BT-ERA5, (2) BC-ERA5, and (3) BC-UniGe. The model performance was assessed against nearshore station data using various statistical metrics. While RMSE and Pearson correlation suggest BT-ERA5, i.e., the coarsest and simplest setup, is the best model (followed by BC-ERA5), we demonstrate that these indicators are not always reliable for performance assessment. The most sophisticated model (BC-UniGe) shows worse values of RMSE or Pearson correlation due to the so-called "double penalty" effect. Here we propose new skill indicators that assess the ability of the model to reproduce the distribution of the observations. This, combined with an analysis of values above the 99th percentile, identifies BC-UniGe as the best model, while ERA5 simulations tend to underestimate the extremes. Although the study focuses on the accurate representation of storm surge by the numerical model, the analysis and proposed metrics can be applied to any problem involving the comparison between time series of simulation and observation. [ABSTRACT FROM AUTHOR]

Tide–surge interaction plays a substantial role in determining the characteristics of coastal water levels over shallow regions. We study the tide–surge interaction observed at seven tide gauges along Singapore and the east coast of Peninsular Malaysia, focusing on the timing of extreme non-tidal residuals relative to tidal high water. We propose a modified statistical framework using a no-tide–surge interaction (no-TSI) null distribution that accounts for asymmetry and variation in the duration of tidal cycles. We find that our modified framework can mitigate false-positive signals of tide–surge interaction in this region. We find evidence of tide–surge interaction at all seven locations, with characteristics varying smoothly along the coastline: the highest non-tidal residuals are found to occur most frequently before tidal high water in the south, both before and after tidal high water in the central region, and after tidal high water in the north. We also propose a semi-empirical model to investigate the effects of tidal-phase alteration, which is one mechanism of tide–surge interaction. Results of our semi-empirical model reveal that tidal-phase alteration caused by storm surges is substantial enough to generate significant change in the timing of extreme non-tidal residuals. To mitigate the effect of tidal-phase alteration on return level estimation, skew surge can be used. We conclude that (1) tide–surge interaction influences coastal water levels in this region, (2) our semi-empirical model provides insight into the mechanism of tidal-phase alteration, and (3) our no-TSI distribution should be used for similar studies globally. [ABSTRACT FROM AUTHOR]

Practitioners at the local and regional scale are under increased pressure to reduce risks to people and property posed by the threats of sea‐level rise (SLR) and associated impacts. To achieve this, a dialog between practitioners and scientists is imperative. Current research documents impacts of SLR, evaluates local SLR adaptation activities, identifies barriers to action, and works to assess local adaptive capacity. Despite this work, there has been little qualitative assessment of practitioners' needs when it comes to translating SLR science into local changes. To fill this gap, we used a combination of semi‐structured interviews and surveys. The interviews revealed practitioners' needs, the tools they use, the challenges they face, and the contexts in which they make decisions. The survey allowed practitioners to rank potential interventions according to the level of impact they believed it would have on coastal adaptation planning. In total our study includes the perspectives of 142 practitioners from 24 states, Puerto Rico, the Mariana Islands, and Barbados. Corroborating earlier work, we find that resources broadly and funding specifically is the largest barrier faced by practitioners. We find that practitioners need more localized information and models supported by on the ground monitoring, decision support resources that allow for comparison of different scenarios, and communication tools that will enable them to engage with key audiences. These needs suggest a critical shift toward building trusted relationship between scientists and local practitioners and the need to bolster organizations that can support a bridge between these two contexts. Plain Language Summary: We describe the needs of practitioners to build resilience in their communities to sea‐level rise (SLR). They are concerned about how SLR will interact with existing natural coastal challenges. These challenges include storm surge, habitat loss, saltwater intrusion, and erosion. Practitioners continue to face challenges related to resources such as lack of funding and lack of staff capacity. They also face social and institutional challenges in the areas of information, commitment, and political environments. As one participant, who is responsible for building resilience in their community said: "Fundamentally, we're relying on the science, but there is a huge gap between scientists and people who are trying to get things done." This quote highlights the challenge of translating SLR science into local actions, such as building a sea wall or restricting development. It points to a need for many to help create a bridge between pure SLR science and those working as coastal planners, sustainability professionals, natural system managers, and other allied professions. Through interviews, we shed light on 38 specific needs in three categories—information, decision support, and communication tools/education opportunities—that would enable practitioners to build resilience in their communities. Based on our survey, we find that very specific information is needed to enable practitioners to build resilience. They need local scale data, on‐the‐ground monitoring, locally calibrated models about increased risks, and information about the relative effectiveness of nature‐based solutions. Practitioners are also looking for communication tools that translate the impacts of SLR into economic values. We recommend a series of interventions that could support practitioners in their work to build resilience to SLR. Key Points: We identified 38 specific needs in three categories—information, decision support, and communication tools/education opportunitiesPractitioners need local scale data, on‐the‐ground monitoring, and locally calibrated models for compound flooding and increased riskThey also need decision‐support resources including information about the effectiveness of solutions and translation into economic values [ABSTRACT FROM AUTHOR]

The economies and livelihoods of many coastal megacities are at serious risk from flooding, despite investments in flood defenses. For instance, in Ho Chi Minh City, the construction of a large‐scale ring‐dike has mitigated negative effects from storm surges, yet damage is still frequently caused by high‐intensity rainfalls leading to nuisance flooding, which is responsible for the highest proportion of flood losses in the city today. Because sustainable flood risk management requires detailed spatial information, we analyze the local risk and its components based on a chain of novel models previously calibrated and validated for Ho Chi Minh City. Furthermore, we assess the effectiveness of two decentralized adaptation options, namely private precautionary measures and rainwater retention, for mitigating pluvial flooding. Our integrated risk assessment reveals that the approaches are complementary, which is a major advantage for their implementation. Implementation of both approaches has the potential to reduce the expected annual damage and the number of annually affected households by 16% and 56%, respectively. This is also reflected in a significant reduction of annual losses per household, which we propose as an additional, people‐centered indicator of flood risk. Moreover, these measures are well‐suited to strengthen citizen participation in risk reduction beyond top‐down protection schemes. Complementing the ring‐dike with decentralized adaptation options can therefore be seen as an effective and generic strategy to alleviate the impacts of nuisance flooding in coastal megacities, such as Ho Chi Minh City, and should be incentivized by decision‐makers. Aside from hydrological and metocean site conditions, both the methodology and findings of this study are transferrable to any coastal megacity facing similar challenges. Plain Language Summary: In many delta cities like Ho Chi Minh City in Vietnam, flooding continues to be a serious threat, despite investments in flood defenses. Even with a large‐scale ring‐dike in place, high‐intensity rainfalls that lead to so‐called nuisance flooding continue to cause considerable damage. To support effective risk management, we analyze flood risk and its components by combining various innovative models that were calibrated and validated for Ho Chi Minh City. Moreover, we assess two decentralized adaptation measures against flooding, namely private precautionary measures and rainwater retention. To evaluate the effectiveness of these adaptation options, we calculate the achievable reduction of annual flood losses and the number of affected households. We also calculate the annual loss per household as a new, more practical indicator of flood risk. Our analysis shows that the two assessed adaptation options are complementary and can significantly reduce flood impacts. By implementing these measures alongside the ring‐dike, decision‐makers can thus adopt an effective strategy to manage flood risk in Ho Chi Minh City and similar settings. Key Points: The damage to residential buildings from pluvial nuisance flooding in Ho Chi Minh City is quantified based on an integrated risk assessmentExpected Annual Damage and Annually Affected Households are combined into a new, people‐centered indicator to evaluate adaptation optionsPrivate precaution and rainwater retention are two complementary, decentralized options to effectively support large‐scale flood protection [ABSTRACT FROM AUTHOR]

Flood risk analyses often focus on a single flooding source, typically storm surge or rainfall‐driven flooding, depending on the predominant threat. However, hurricanes frequently cause compound flooding through significant storm surges accompanied by heavy rainfall. This study employs a hydrodynamic model based on Delft3D‐Flexible Mesh that couples flow, waves, and rainfall‐driven flow to simulate five historical tropical cyclones in Virginia's southeast coastal region. These storms produced varying intensities of storm surge and rainfall in the study area. Model simulations, incorporating rainfall through a rain‐on‐grid approach, account for the dynamic interaction between storm tides, and pluvial flow and enable the definition of flood zones as hydrologic, transitional, and coastal zones. This compound flooding model was validated with water level data from in‐water and overland gauges. The results indicate that the magnitude of the coastal zone correlates strongly with the extent of the surge‐inundated area (SIA) obtained from simulations that only considered storm surges. The extent of the transitional zone correlates strongly with the product of SIA and total rainfall. As an additional measure for flood hazards besides water depth, we calculated flow momentum flux at different flood zones to assess potential damage from hydrodynamic loads on structures, vehicles, and pedestrians. A strong correlation was found between the magnitude of the surge and momentum flux. Furthermore, high rainfall rates and winds can cause a significant increase in momentum flux locally. Understanding flood zones and their flow dynamics helps to identify effective flood risk management strategies that address the dominant flood driver. Plain Language Summary: Flood risk analyses in coastal areas usually study storm surges and rainfall impacts separately. However, hurricanes often cause compound flooding which stems from both sources. This research studies compound flooding using a computational model to simulate five hurricanes that hit coastal Virginia and had a range of surge and rainfall intensities. We identified three flood zones: areas flooded dominantly by rainfall (hydrologic), areas where both surge and rainfall contribute to flooding (transitional), and areas dominated by storm surge (coastal). The extent of the coastal zone correlated strongly with the magnitude of storm surge, and the extent of the transitional zone correlated very strongly with the area inundated by storm surge multiplied by total rainfall. Additionally, we investigated flow momentum, as a measure of flood force on objects. While a large surge causes a large flow momentum, heavy rain and strong winds can create energetic flows in the hydrologic zone too. Analyzing flood zones and flow momentum helps to identify proper flood mitigation measures and quantify their efficiency. For example, flood gates or levees are suitable for coastal zones, and improvements in drainage systems and inland green infrastructure are suitable for hydrologic zones, while a combination suits transitional zones. Key Points: A hydrodynamic model for compound flooding is used to define hydrologic, transitional, and coastal zones at city and neighborhood scalesThe area of the transitional zone correlates very strongly with the inundated area in storm surge simulations multiplied by total rainfallFlow momentum flux, as a measure of flood force, is influenced by surge magnitude, wind, and rainfall intensity [ABSTRACT FROM AUTHOR]

Extreme weather events, such as hurricanes with intense rainfall and storm surges, are posing increasing challenges to local communities worldwide. These hazards not only result in substantial property damage but also lead to significant population displacement. Federal disaster assistance programs are crucial for providing financial support for disaster response and recovery, but the allocation of these resources often unequal due to the complex interplay of environmental, social, and institutional factors. Relying on datasets collected from diverse sources, this study employs a structural equation model to explore the complex relationships between disaster damage (DD), social vulnerability (SV), public disaster assistance (PDA), the national flood insurance (NFI), and population migration (PM) across counties in the contiguous US. Our findings reveal that communities with lower SV tend to experience higher levels of DD across US counties. SV is negatively associated with PM, PDA, and NFI, both directly and indirectly. Furthermore, PDA is positively linked to PM, whereas DD has a direct negative effect on PM but an indirect positive effect through PDA. [ABSTRACT FROM AUTHOR]

A storm surge, classified as an extreme natural disaster, refers to unusual sea level fluctuations induced by severe atmospheric disturbances such as typhoons. Existing reanalysis data, such as ERA5, significantly underestimates the location and maximum wind speed of typhoons. Therefore, this study initially assesses the accuracy of tropical cyclone positions and peak wind speeds in the ERA5 reanalysis dataset. These results are compared against tropical cyclone parameters from the IBTrACS (International Best Track Archive for Climate Stewardship). The position deviation of tropical cyclones in ERA5 is mainly within the range of 10 to 60 km. While the correlation of maximum wind speed is significant, there is still considerable underestimation. A wind field reconstruction model, incorporating tropical cyclone characteristics and a distance correction factor, was employed. This model considers the effects of the surrounding environment during the movement of the tropical cyclone by introducing a decay coefficient. The reconstructed wind field significantly improved the representation of the typhoon eyewall and high-wind-speed regions, showing a closer match with wind speeds observed by the HY-2B scatterometer. Through simulations using the FVCOM (Finite Volume Community Ocean Model) storm surge model, the reconstructed wind field demonstrated higher accuracy in reproducing water level changes at Tanxu, Gaoqiao, and Zhangjiabang stations. During the typhoon's landfall in Shanghai, the area with the greatest water level increase was primarily located in the coastal waters of Pudong New Area, Shanghai, where the highest total water level reached 5.2 m and the storm surge reached 4 m. The methods and results of this study provide robust technical support and a valuable reference for further storm surge forecasting, marine disaster risk assessment, and coastal disaster prevention and mitigation efforts. [ABSTRACT FROM AUTHOR]

Typhoons, extratropical cyclones, and cold fronts cause strong winds leading to storm surges and waves in the Bohai Sea. A wave–flow coupled numerical model is established for storm events observed in 2022 caused by three weather systems, to investigate how storm waves are modulated by wave–tide–surge interaction (WTSI). Wave response is basically controlled by water level change in coastal areas, where bottom friction or breaking dominates the energy dissipation, and determined by the current field in deep water by altering whitecapping. Wave height increases/decreases are induced by positive/negative water level or obtuse/acute wave–current interaction angle, leading to six types of field patterns for significant wave height (Hs) responses. For the three storm events, Hs basically changed within ±5% in central deep water, while the maximum increase/decrease reached 160%/−60% in the coastal area of Laizhou Bay/Liaodong Bay. Based on maximum Hs and its occurrence time, WTSI modulation is manifested as the superposition effect of wave–tide and wave–surge interactions in both space and time scales, and occurrence time depends more on tide than surge for all three storms. The enhancement/abatement of WTSI modulation happens for consistent/opposite changing trends of wave–tide and wave–surge interaction, with the ultimate result showing the side with a higher effect. [ABSTRACT FROM AUTHOR]

Many cities worldwide are increasingly threatened by compound floods resulting from the interaction of multiple flood drivers. Simultaneously, rapid urbanization in coastal areas, which increases the proportion of impervious surfaces, has made the mechanisms and simulation methods of compound flood disasters more complex. This study employs a comprehensive literature review to analyze 64 articles on compound flood risk under climate change from the Web of Science Core Collection from 2014 to 2024. The review identifies methods for quantifying the impact of climate change factors such as sea level rise, storm surges, and extreme rainfall, as well as urbanization factors like land subsidence, impervious surfaces, and drainage systems on compound floods. Four commonly used quantitative methods for studying compound floods are discussed: statistical models, numerical models, machine learning models, and coupled models. Due to the complex structure and high computational demand of three-dimensional joint probability statistical models, along with the increasing number of flood drivers complicating the grid interfaces and frameworks for coupling different numerical models, most current research focuses on the superposition of two disaster-causing factors. The joint impact of three or more climate change-driving factors on compound flood disasters is emerging as a significant future research trend. Furthermore, urbanization factors are often overlooked in compound flood studies and should be considered when establishing models. Future research should focus on exploring coupled numerical models, statistical models, and machine learning models to better simulate, predict, and understand the mechanisms, evolution processes, and disaster ranges of compound floods under climate change. [ABSTRACT FROM AUTHOR]

Coastal zones are increasingly threatened by extreme sea level events, with storm surges being among the most hazardous components, especially in regions prone to tropical cyclones. This study aims to explore the factors influencing the performance of numerical models in simulating storm surges in the tropical Atlantic region. The maxima, durations, and time evolutions of extreme storm surge events are evaluated for four historical hurricanes against tide gauge records. The Advanced Circulation (ADCIRC) and Nucleus for European Modelling of the Ocean (NEMO) ocean models are compared using similar configurations in terms of domain, bathymetry, and spatial resolution. These models are then used to perform sensitivity experiments on oceanic and atmospheric forcings, physical parameterizations of wind stress, and baroclinic/barotropic modes. NEMO and ADCIRC demonstrate similar abilities in simulating storm surges induced by hurricanes. Storm surges simulated with ERA5 atmospheric reanalysis forcing are generally more accurate than those simulated with parametric wind models for the simulated hurricanes. The inclusion of baroclinic processes improves storm surge amplitudes at some coastal locations, such as along the southeastern Florida peninsula (USA). However, experiments exploring different implementations of wind stress and interactions among storm surges, tides, and mean sea level have shown minimal impacts on hurricane-induced storm surges. [ABSTRACT FROM AUTHOR]