Significant Flood Research Articles

Exploring River’s Flood Dynamics: Integrating HEC-RAS 1-D Modelling and Geospatial Techniques for the Karjan River in Gujarat’s Narmada Basin, India

Floods rank among the most devastating natural disasters, causing extensive damage to property and severe impacts on communities. Effective management and mitigation of flood risks necessitate reliable data regarding flood depth, discharge, and extent. The Karjan River Basin’s low-lying regions experienced significant flooding in 2020. This research utilizes the latest new HEC-RAS version for one-dimensional hydrodynamic flood modelling for the Karjan River in low-lying areas and the merging point of the Karjan River Basin in Narmada River, emphasizing geospatial techniques. The study showcases the analytical process of the new HEC-RAS v6 in spatial analysis. River features like bank lines and cross-sections were derived from ALOS Palsar for flood modeling. An unsteady flow simulation was conducted to model water dynamics, yielding water depth results viewable in the HEC-RAS geospatial RAS mapper. Flood depth maps created for 2020 reveal that areas low lying area i.e. Dhamncha, bhadam, Juna Rundh and surrounding area near the merging point of Karjan River are prone to floods when river discharge surpasses 8836 cubic meters per second. Model accuracy was verified by comparing simulated outcomes with historical data from the mentioned events, demonstrating the model’s precision and reliability.

Natural Flood Risk Management in Tropical Southeast Asia: Prospects in the Biodiverse Archipelagic Nation of the Philippines

ABSTRACTNatural flood management (NFM) has gained prominence as a flood risk management approach in temperate settings but lacks extensive applied examples and evidence in tropical settings, despite significant ecosystem degradation and high flood risk exposure. Tropical river catchments often experience highly variable hydrographs (i.e., prone to flash floods) and intense rainfall from monsoon and typhoon‐dominated weather systems that can cause landslides and sediment‐transporting river flows. These conditions provide a backdrop to the prospects for NFM in tropical Southeast Asia, of which the Philippines is representative. Catchments in the country are typically small and thus associated with short hydrological response times. They are also characterized by diversity of river types, high rates of lateral mobility, extensive downstream urbanization, and complex land use mosaics at the coast. Consideration of NFM as a conceptual framework in the Philippines may enable conversations about adapting existing flood risk management approaches. To explore these NFM alternatives, we conceptualize opportunities in a typical catchment that we divide into four nested, connected parts: managing headwaters as sponges; conserving and restoring river and floodplain width; blue‐green infrastructure in urban areas; and maintaining and creating space for water in fluvial‐coastal settings. There is potential in countries such as the Philippines to adopt NFM strategies that have shown promise in temperate regions and select Southeast Asian countries, where emerging evidence supports their effectiveness. Monitoring tropical NFM interventions remains crucial to gather evidence supporting broader application of nature‐based solutions for flood risk mitigation and biodiversity loss in tropical Southeast Asia.

Investigation of the flow characteristics of slit check dams using novel models

Floods, which cause loss of life and property and destruction of the environment, have devastating effects on socio-economic welfare. Slit-check dams are essential structures for managing the transport of silt and woody debris, especially in events of significant floods. The current study presents the hydraulic characteristics of slit-check dams with different geometries for experimental and numerical tests. First, the Butterfly model was produced with a 3D printer and examined experimentally. Then, the Butterfly model was validated extensively using OpenFOAM (v7) software for the numerical analysis. Finally, the other models were examined numerically using the k-ε turbulence model. The changes in water surface profile, velocity profiles, energy dissipation rates, and streamlines were comprehensively examined and discussed. The results showed that slit-check dams caused hydraulic jumps and dissipated flow energy. The Arced and Rectangular models, in particular, demonstrated a significant performance for energy dissipation, which is essential for flood management. Water surface profiles are directly affected by discharge. Moreover, the cross-sectional length of the model in question significantly affects the water surface profile. Accordingly, an increase was observed in the velocity profiles along the slit-check dam. While the maximum velocity for all unit discharge was observed in the V-shaped model, the minimum velocities were observed for the Arced and Rectangular models. Thus, the energy absorption performance of Arced and Rectangular models is higher.

Morphometric parameterization of flash flood risk assessment

Individual morphometric characteristics of river basins significantly impact their activity; they affect the flow rate of water, water accumulation in the river basin, water runoff time and other attributes that affect their intensity during flash floods and hydrological droughts. The aim of the paper is to express the risk and impact of flash floods in the Topla River basin (Slovakia) and its sub-basins with regard to the morphometric characteristics of the area. The studied locality, especially the spring of the Topla river, belongs to the area with an existing, potentially significant flood risk threatening not only important localities but also the population. The objective is to support the territories with flood mitigation measures by assessing the basin morphometric factors and classifying such areas into high, medium and low-risk categories of flash floods. The model situation is developed in the ArcGIS program, where the selected important morphological characteristics are assigned to all sub-basins for the Topla river together with its assessment. For each characteristic, the level of risk affecting the flash flood is determined. An important part of this study is developing a river basin susceptibility scale to flood activity in terms of morphometric characteristics obtained from available literature, empirical relationships and human experiences. The result of the sensitivity risk map of the upper part of the Topla river basin is to show where adverse impacts on people and the surrounding environment are expected after flash floods hit (or in the event of hydrological droughts).

Modelling of shallow groundwater levels and interaction with drainage system and streams under the impact of climate change

ABSTRACT Under the impact of climate change, groundwater levels are anticipated to increase in temperate climatological zones with increased precipitation and sea level rise. Urban areas located at low elevations are especially at risk, and increased shallow groundwater levels can lead to flooding, water seepage into basements, capacity problems in water infrastructure, etc. Furthermore, old sewer systems can act as drains by allowing groundwater to seep into the sewer system. This process can artificially maintain the groundwater level low, and therefore if the sewer system is rehabilitated, the problems are even increased further if necessary solutions are not included in the planning process. In this article, we analyze an urban catchment in Aalborg, Denmark, which is currently facing problems with high groundwater levels. By simulating the groundwater interaction with sewer systems and watercourses, we show that the groundwater table can increase up to 1 m under the impact of sewer rehabilitation and climate change. This increase will lead to significant flood risk in the residential area. We propose multiple technical solution scenarios and evaluate their effectiveness, demonstrating how the impact of increasing groundwater levels can be mitigated through implementation of drains during sewer reconstruction, but not completely avoided.

Research on optimal scheduling of minor and moderate floods for cascade reservoirs in the lower reaches of the jinsha river considering power generation

The comprehensive cascade reservoir system is extensively used for flood control and power generation. Traditional reservoir scheduling often treats these tasks as competing objectives, prioritizing flood control during the flood season and neglecting power generation benefits. This approach, primarily applied to large floods, leads to hydraulic resource wastage and power generation loss during minor and moderate floods. The lower Jinsha River cascade reservoirs have significant flood control storage capacity, allowing part of the capacity to be used for maintaining higher water levels without compromising safety under minor and moderate floods within a 20-year return period. This paper proposes an optimal scheduling model that considers both flood control and power generation tasks for the lower Jinsha River cascade reservoirs. The Multi-objective Particle Swarm Optimization (MOPSO) algorithm was used to find non-inferior solution sets. An evaluation index system was developed to select optimal solutions under different flood frequencies, using the Minimum Discriminant Information Principle and VIKOR model. The results indicate that the optimal scheduling scheme under 20-year, 10-year, and 5-year return period floods can enhance power generation by 1.64, 1.71, and 1.35 billion kWh, respectively, compared to conventional scheduling. This approach supports coordinated flood control and power generation scheduling, contributing to the high-quality development of the Yangtze River Economic Belt.

Multiple criteria and statistical sentiment analysis on flooding

The World Bank lists flooding as one of the main pressures on a community. Flooding can affect development prospects and potentially reverse decades of progress in the alleviation of poverty and in development. Flooding-related information usually involves many stakeholders, objects, and significant details. We examined linkage between the density of 506 flood management keywords from documents found via Google Search and 32 macroenvironment indicators for 76 countries, developing 506 neural networks models. These models show that flood management keywords are interconnected with the environmental, social, economic, political, and cultural dimensions of the examined countries. The models demonstrate that improvements in a country’s sustainability and performance metrics are followed by an increase in flood keyword use. Microsoft Azure AI and ChatGPT were used to generate abstractive summaries for the 100 most dense and statistically significant flood management keywords and 28 macroenvironment indicators for the individual countries included in our analysis, and for the world. We reduced the number of flood keywords density variables from 506 to 100 by selecting only the most relevant ones in order to generate abstractive summaries. Our Web of Science Sentiment Analysis Articles Model and Map of the World demonstrates that nations with an unfavorable macroenvironment published disproportionately fewer papers on sentiment analysis. This research benefits stakeholders by providing comprehensive and holistic information and data analysis, focusing on evidence-based flooding information.

From sandstorms to deluges: assessing flood risks in Al Ain City, United Arab Emirates

In recent years, the United Arab Emirates (UAE) has experienced a marked increase in extreme rainfall events, challenging urban planning and infrastructure. This study investigates four extreme rainfall events in Al Ain, UAE, between 2007 and 2020, using data from 11 rain gauges and estimates from three satellite precipitation products. These events set new rainfall records, with some gauges recording up to 195.7 mm and intensities exceeding 175 mm/hr. Comparisons revealed significant discrepancies among satellite products, which underestimated three events and overestimated one. A watershed encompassing Al Ain was delineated, and runoff from these events was simulated using the fully distributed, physically based GSSHA hydrologic model. The model provided detailed, spatially explicit runoff estimates, highlighting urban areas of Al Ain as particularly vulnerable to flooding. Despite low runoff ratios (0.11% to 3.14%) due to high infiltration rates, significant flooding occurred in urban regions, emphasizing compounded flood risks from intense rainfall and rapid urban expansion. The study discusses general mitigation strategies that can be considered to enhance Al Ain’s resilience, ensuring the safety of residents and infrastructure and managing escalating flood hazards amid increasingly extreme weather patterns. Thoroughly evaluated strategies are essential for adapting to the dynamic climate and safeguarding urban areas from future extreme weather events.

India's flood risk assessment and mapping with multi-criteria decision analysis and GIS integration

ABSTRACT India's diverse geography presents significant flood risks, analyzed in this study using geographic information systems and multi-criteria decision analysis. This comprehensive flood risk assessment considers seven parameters: mean annual precipitation, elevation, slope, drainage density (DD), land use and land cover, proximity to roads, and distance to rivers. The findings indicate that flood vulnerability is primarily influenced by rainfall, elevation, and slope, with DD, land use, and proximity to roads and rivers also playing crucial roles. Experts weighed these factors to create a thorough flood risk map using the normalized rank index and normalized weight index, categorizing areas into five risk levels: very high, high, moderate, low, and very low. The study reveals that 3.40% of the area is at very high risk, 32.65% at high risk, 39.72% at moderate risk, 20.97% at low risk, and 3.25% at very low risk. These results highlight how human and natural factors interact to influence flood risk, with vulnerable areas characterized by low elevations, steep slopes, high drainage densities, and proximity to rivers or roads. The findings provide valuable insights for policymakers, scientists, and local authorities to develop strategies to mitigate flood losses across India's varied landscapes.

Flood Risk Assessment and Its Implications on Critical Infrastructure Resilience in Nigeria

Flooding is one of the recurrent natural disasters in Nigeria that poses huge threats to not just people but also critical infrastructures. In 2024, the Federal Ministry of Water Resources and Sanitation and the Nigeria Hydrological Services Agency (NIHSA) identified 31 states including the FCT as high-risk areas for significant flood impacts. The impact of floods generally has caused devastating damage to critical infrastructures resulting from high rain intensities for a long duration. It becomes pertinent to evaluate the impact of floods on critical infrastructures like roads, bridges, residential buildings, water supply systems, and electricity facilities. Thus, this research seeks to explore the vulnerabilities and impacts of floods on critical infrastructure which is fundamental to economic growth, development, and coping mechanisms. A structured questionnaire was distributed among a sample of 90 including government department, construction industry, and community members to seek their views on the vulnerability risk of infrastructure and flood sources. Results indicate that most of the damages reported 42% were due to the destruction of roads and bridges, followed by residential houses at 31%. The main cause of flooding identified by 54% of respondents was poor drainage systems, while 31% cited poor waste management as a contributing issue. Hence, restoration of the drainage systems, implementation of prohibitions on encroachment of flood-prone areas and improvement of early warning systems are critical and pressing. The uniqueness of the study lies in its effort to address the gaps and challenges that exist in infrastructure resilience by identifying the most critical elements that are prone to risks and proposing mitigation measures against floods in the urban centers of Nigeria which are experiencing rapid growth.

Understanding dominant hydrological processes and mechanisms of water flow in a semi-arid mountainous catchment of the Cape Fold Belt

Improving our understanding of streamflow characteristics, water storage, and dominant flowpaths in mountainous regions is important as mountains play a vital role in delivering water to lowlands, particularly in semi-arid areas. This work characterized water sources, flowpaths, and streamflow characteristics in the semi-arid, mountainous Kromme catchment in Eastern Cape Province of South Africa. Precipitation, shallow and deep groundwater levels, and streamflow data were analysed to identify patterns that indicate the occurrence and/or dominance of certain processes, responses, and flowpaths. Results of the study demonstrated how the catchment responds to rainfall events across seasons and rainfall intensities. Steep and rocky areas that make up much of the catchment contributed to significant flood peaks after high-intensity storms. Quick and slow responses in flow after rainfall events indicated the dominance of both surface and subsurface flowpaths respectively. Furthermore, surface and subsurface flows were significant in recharging the floodplain alluvial aquifer as well as maintaining streamflow during dry periods. Average annual runoff coefficients were low (0.09), which implied large evapotranspiration (ET) withdrawals from dominant flowpaths and/or storage in inactive groundwater. The Kromme catchment has a sizeable floodplain with large alluvial aquifers, which make significant contributions to catchment storage and outflows. Overall, the catchment streamflow was sustained by baseflow (for ∼50% of the time). Recession patterns suggested that the channel receives flow from different storages with the alluvial and bedrock aquifers as main contributors. Flow contributions had different rates with maximum recession periods up to 22 days, indicative of interflow dominance and floodplain drainage. Throughout the monitoring period, the river system was gaining flow at the different monitored sites during both low and high flow conditions. The channel was also gaining from the mountain bedrock through tributary flows and from the alluvial aquifer. A conceptual model of flowpaths and processes at the catchment scale is presented to improve the understanding of catchment scale hydrological processes in a semi-arid meso-scale mountainous environment.

Country-wide assessment of plastic removal rates on riverbanks and water surfaces

Plastic pollution in river basins poses a significant environmental challenge, particularly in Japan, located in the northwestern North Pacific, often referred to as a hotspot for plastics. This study quantified the annual recovery of anthropogenic plastic litter from riverbanks and water surfaces, utilizing a nationwide cleanup dataset provided by the Japanese Ministry of Land, Infrastructure, Transport and Tourism. The dataset includes the amount of litter recovered through volunteer and administrative cleanup campaigns from 2016 to 2020 in 109 Japanese river basins. Total plastic recovery ranged from 763 to 1177 tons/year, averaging 938 tons/year. Basin-specific recovery was associated with extreme weather events, such as typhoon approaches and heavy rain, which caused significant flood damage in local regions. The estimated annual plastic recovery was an order of magnitude smaller than the previously estimated annual emission of land-based plastic.

Flood-induced mobility in rural and urban coastal jurisdictions: a homeowner’s perspective

AbstractCoastal flooding often exceeds homeowners’ capacity to cope with repetitive damages and profoundly disrupts their livelihoods. Permanent relocation has been proposed as a solution for some coastal areas experiencing recurrent flooding and anticipating acceleration of impacts. However, it is unclear if homeowners living in such areas would support this strategy, where they would choose to go, and why. This study evaluates the willingness to relocate and the reasoning behind it among rural and urban homeowners residing in coastal high-risk areas. The rural versus urban comparison explores how attitudes toward relocation differ between these settings with distinct sociodemographic, economic, and cultural profiles. A mail survey administered on the Eastern Shore, Maryland, and in the Hampton Roads metropolitan area, Virginia, measured how willingness to relocate differs across the socioeconomic spectrum, prior flood exposure, concerns with flood impacts, and preferences for relocation destination. The survey responses were analyzed using descriptive and inferential statistics. The results show that more than one-third of respondents would consider relocating. The willingness to relocate was marginally influenced by socioeconomic factors and flood experiences and instead was significantly correlated with the risk of disastrous flooding, inadequate insurance compensation, and worsening crime. However, data show a clear shift in relocation support and the distance of the preferred destination from minor to significant flooding. Rural respondents are slightly less likely to relocate than urban ones. Descriptive statistics indicate nuanced differences in flood experiences, reasons to relocate, and preferences for a new destination between rural and urban populations.

Gender Differences in Years of Life Lost resulting from the 2015 Gorkha Earthquake in Nepal

Abstract Background Nepal has a history of regular natural hazards, including significant earthquakes and floods. Previous studies have shown that females, particularly younger females, are more likely to die due to disasters compared to males. This study aimed to explore gender differences in mortality - measured in Years of Life Lost (YLL) - caused by the 2015 Gorkha earthquake across 41 districts of Nepal. Methods Mortality counts were derived from the Nepal Police Report. YLL was estimated by multiplying mortality counts (stratified by age, gender, and district) by age-conditional life expectancy from the 2019 Global Burden of Disease reference life table. Both absolute numbers and rates of YLL per 100,000 population were calculated. YLL per deaths, stratified by age-gender-and-location, were estimated and compared. Male-to-female YLL rate ratios were estimated as well, and compared across districts. Results The 2015 Gorkha earthquake resulted in 8,950 deaths (females: 56.1% versus males: 43.9%), accounting for 526,617 YLL. Males had a slightly higher number of YLL per death (59.2) compared to females (58.5); this is mainly due to the different number of deaths between males and females. YLL per deaths ranged from 65.4 (Rautahat district) to 0 (in several districts) among males and, from 65.3 (Rautahat district) to 0 (in several districts) among females. The YLL rate per 100,000 population was higher for females (3,158 per 100,000) than for males (2,575 per 100,000). Approximately 40% of the districts had male-to-female YLL rate ratios of less than one, which can be partly explained by the gender distribution of the population at rik of dying due to earthquake. Conclusions The study found relatively higher YLL per death for males and higher YLL rates for females. This underscores the necessity to further investigate the factors that contribute to fatalities from earthquakes, especially in lower middle income countries such as Nepal. Key messages • Gender disparities in mortality following the 2015 Gorkha earthquake in Nepal were addressed using Years of Life Lost (YLLs); males had higher YLL per death, while females had higher YLL rates. • Exploring the factors that contribute to earthquake-related fatalities should be a priority for disaster mitigation strategies.

A review of paleofloods in the middle-lower reaches of the Yangtze River during the Holocene: Processes, causes and effects

The understanding of the flooding processes in the entire basin of the middle-lower reaches of the Yangtze River (MLRYR) during the Holocene remains elusive. This is primarily attributed to the constraints posed by site-scale data characterized by limited spatiotemporal resolutions, compounded by conflicting results of the reconstructed Holocene paleoflood records in some of the previous studies. In this study, by synthesizing 114 paleoflood data with robust evidence of flood occurrence (including timing and location of flood occurrence), we comprehensively reconstructed the first continuous Holocene paleoflood record that cover the entire basin of the MLRYR. The results show that at the onset of the Holocene, flood frequency peaked notably in the middle reaches of the Yangtze River (MRYR), with no corresponding peak observed in the lower reaches of the Yangtze River (LRYR). However, in both the MRYR and LRYR, a significant flood frequency peak emerged around 8.0 ± 0.5 ka BP, and scarce flood occurrences appeared approximately 7.5–5.0 ka BP. This scarcity shifted abruptly to a surge in flood frequency from 5.0–4.0 ka BP. Following this, the MRYR witnessed three successive peaks in flood frequency, occurring at approximately 3.0 ka BP, 1.8 ka BP, and 1.0 ka BP, respectively. In contrast, flood events in the LRYR were infrequent during the 3.0–2.0 ka BP period, followed by a surge in frequency from 2.0 ka BP onwards. We further explored the driving mechanisms of paleofloods in the MLRYR and found that floods were more likely to occur during periods of weakened EASM, characterized by wet and unstable climate conditions in the MLRYR. Marine erosion may be also a key factor in the lack of geological evidence for palaeofloods during the early Holocene. Additionally, variations in the ISM and human activities during the late Holocene have significantly influenced the occurrence of floods in the MLRYR. By comparing the paleoflood frequency with the spatial distribution and number of archaeological sites in the MLRYR, respectively, we propose that the period of flood scarcity during the middle Holocene may have facilitated the development of rice agriculture and the prosperity of ancient settlements. In contrast, during flood-prone period, ancient societies adapted and coped with floods by migrating to higher terrain during the early Holocene and implementing simple hydraulic engineering techniques during the late Holocene.

Evaluation of WRF model performance with different microphysics schemes for extreme rainfall prediction in Lagos, Nigeria: Implications for urban flood risk management

In Nigeria, particularly in urban areas like Lagos, flooding is a frequent natural hazard. In 2011, Lagos experienced one of its worst floods resulting in significant economic losses and displacement of people. In recent years, Lagos has continued to grapple with flooding challenges, with an equally significant flood episode occurring in 2021. This study focuses on predicting floods and forecasting extremely heavy rainfall in West Africa's equatorial zone using the Weather Research and Forecasting (WRF) model, particularly in humid tropical environments like Lagos. The study discusses the need to review existing flood models and adopt alternative flood models to address the limitations of flood prediction. As potential causes of these rainfall episodes, the interconnections between synoptic systems such as tropical easterly waves, southwesterly winds related to the West African Monsoon, and local topography and oceanic conditions are investigated. Three key metrics: root mean square error (RMSE), mean bias (MB), and mean absolute error (MAE) are used to assess the effectiveness of the computational model. Results indicate that the WRF model, specifically when using the Thompson parameterisation, can estimate the amount of rainfall accumulated over a 24-h period. This suggests that the model can predict the size of daily precipitation during intense rain events. The Thompson scheme shows better performance compared to the WSM6 scheme while evaluating the stations and episodes. During the rainfall episode on July 10, 2011, Thompson's spatial rainfall predictions were better than WSM6, resulting in a decrease in root mean square error (RMSE) of 15–31% depending on the area. Simulations of the July 2021 episode also show better performance, with a decrease in RMSE of 11–25% when comparing Thompson to WSM6 scheme. The Thompson scheme’s improved ability is directly linked to a more accurate depiction of the microphysical mechanisms that control the rainfall formation. By explicitly simulating the dynamics of ice crystals and graupel, it is possible to accurately replicate the processes of orographic lifting and moist convection that are responsible for driving intense monsoon precipitation. In addition, Thompson scheme shows a reduced degree of systemic bias in comparison to WSM6, with a 75% reduction in the average bias in rainfall accumulation over the research area. The combination of the advanced Thompson microphysics method and WRF's atmospheric dynamics shows a high level of accuracy in predicting intense rainfall and the risk of floods in this area with diverse tropical topography.

Preparedness and Response to Flooding Risks by Kenya Wildlife Service in Hells Gate National Park, Nakuru County, Kenya

Floods are short-lived events that occur abruptly with little to no warning and are among the most dangerous disasters relating to weather due to the hazardous conditions caused for people, the destruction of property and the loss of life as well. Thus, minimizing flooding impacts timely and passing accurate information is critical in flood preparedness and response. Previous studies have focused on the probability of floods occurring and their magnitude, therefore leaving a knowledge gap on preparedness and response to flooding risks in national parks by government agencies in Kenya. Hell’s Gate National Park experiences significant flash flooding; therefore, it provided a good venue to study the levels of preparation and response mechanisms available in Kenyan national parks. The objectives of the study were to understand the level of preparedness and mechanisms to respond to flooding events by Kenya Wildlife Service in Hells Gate National Park. The study was guided by a descriptive research design which involved collecting quantitative and qualitative data from 118 park users and other key informants. The study found that the Kenya Wildlife Service plays a crucial role in flood preparedness and response, but there is room for improvement in early warning systems, hazard map distribution, and user education because only 36.6% of the respondents were aware of escape routes to be used during floods. In terms of recommendations, the study found that it is crucial to enhance the existing flood preparedness and response mechanisms within the park including investing in advanced technology for early warning systems, conducting regular drills, and fostering community engagement and partnerships, continuous improvement of flood preparedness and response plans, along with a robust communication strategy.

Flood Risks Analysis in Upton Upon Severn: Assessing the Baseline Conditions and Future Scenarios for 100 and 1000-year Flood Events with a 2050 Climate Change Perspective.

This paper investigates the flood risks in Upton upon Severn, a town in Worcestershire, England, which is prone to fluvial flooding from the River Severn. Historical events, such as the significant floods of 1947 and 2007, highlight the town’s vulnerability and underscore the importance of analysing current and future flood risks. This research uses a one-dimensional hydraulic model, using Flood Modeller and QGIS software, to assess baseline flood conditions and predict the potential impacts of severe and extreme flood events, including 1 in 100-year and 1 in 1000-year flood scenarios. Additionally, it examines the projected effects of climate change by incorporating a 20% increase in flood risk estimates for the year 2050. The model results reveal that the baseline scenario poses limited flood risks, with only 17 properties affected, and key infrastructure like the A4104 road remains passable. However, under the 1 in 100-year event, approximately 336 properties are at risk, with significant road blockages and a flooded area of 5.09 Km2. The 1 in 1000-year flood scenario predicts a peak flow of 1807 m3/s, threatening more properties and covering a larger area of land. When climate change is factored into the 1 in 100-year scenario, the risks become similar to those of the 1 in 1000-year event, with 500 properties and key infrastructure, including the fire station and primary school, at risk and the A4104 road becoming impassable. These findings provide vital insights for flood risk management, especially given the possible effects of climate change, and stress the need for long-term solutions to flooding.

Tsunami propagation and flooding maps: An application for the Island of Lampedusa, Sicily Channel, Italy

AbstractThe Mediterranean coastlines are densely populated zones which host key socio‐economic and commercial activities. For this reason, coastal areas are vulnerable sites in case of natural disasters as tsunamis that can strike coasts causing widespread damage to the population and facilities. For these reasons, several studies were performed over the last decade to study the impact of tsunami waves on the coasts. This research assessed the inundation risk due to a tsunami wave which can hit the southeastern coast of Lampedusa Island. The coastal low‐lying geomorphological setting of the southeastern part of the island led to significant socio‐economic growth, but Lampedusa falls within the Mediterranean Sea, a high‐tsunamigenic area, therefore, the need to investigate tsunami propagation and coastal flooding of this sensitive site emerged. For this scope, a calculation chain model was implemented incorporating three steps: the DELFT‐3D software for earthquake effects modelling, MIKE 21 Flow Model FM for nearshore propagation and HEC‐RAS for onshore tsunami inundation modelling. The simulations illustrate the impact of three tsunami scenarios with different magnitudes (Mw 8.5, 7.5, 6.5) generated by hypothetical earthquakes in the Hellenic Arc. In the Mw 8.5 magnitude scenario, significant flooding occurs in the harbour region, with maximum water depths reaching approximately 3.5 m. The maximum water velocity in this scenario reaches about 15 m/s in the eastern portion, adjacent to cliffs impacted by the tsunami wave. In contrast, the Mw 7.5 magnitude scenario demonstrates reduced flooded areas, with the cliffs containing the waves and preventing further flooding. Water depths and velocities in the Mw 7.5 scenario remain minimal. Changes in both propagation and flooding are not significant between scenarios Mw 7.5 and Mw 6.5. This methodology can be employed for more accurate tsunami wave simulations not only in the Mediterranean region but also in various case studies.

Social dimensions of climate‐induced flooding in Jakarta (Indonesia): The role of non‐point source pollution

AbstractBecause of its low‐lying location, urbanization, and inadequate infrastructure, Jakarta (Indonesia) has experienced an increase in annual flooding events, rising from an average of five significant floods per year in the 1990s to over 20 annually (2010–2020). With climate change exacerbating extreme weather events, Jakarta encounters escalating risks of flooding. Although the recurrent flooding is exacerbated by non‐point source (NPS) of pollution such as urban runoff and agricultural discharge that contribute to 40% of total pollutants leading to flood‐related issues in Jakarta, none has investigated this research gap. To reflect its novelty, this work explores the implications of climate change on the annual flooding in Jakarta by focusing on NPS and analyzes their impacts from social perspectives. This work also underscores the implications of flooding on livelihoods, health, and social cohesion in Jakarta. Focus group discussion with affected residents was used to shed light on the coping strategies employed in response to recurrent floods, ranging from community‐based initiatives to reliance on informal networks. The empirical findings show that the implications of flooding extend beyond physical damages. Displacement of communities, loss of livelihoods, disruption of essential services, and increased health risks are among the social impacts experienced by local residents. Vulnerable populations, including low‐income communities residing in informal settlements, bear their consequences. Economic losses from flooding amount to USD 500 million annually, impacting over 1 million residents. However, recent interventions have led to a 15% reduction in peak flood levels and a 20% reduction in flood duration in affected areas. Community resilience has also improved, with a 25% increase in flood insurance coverage and a 20% rise in community response initiatives. Overall, this study highlights that climate change exacerbates annual flooding in Jakarta, significantly impacting vulnerable communities through NPS pollution. Addressing the challenges requires integrated approaches combining effective pollution control, resilient infrastructure, and community engagement to mitigate social and long‐term environmental impacts.Practitioner Points Climate‐induced flooding disproportionately affects vulnerable communities in Jakarta. Non‐point source pollution from urban runoff contributes to the severity of flooding in Jakarta. Waterborne diseases, disruption of livelihoods, and reduced access to clean water are major concerns identified in the study. The study highlights the importance of community‐based adaptation strategies to mitigate the impact of flooding and pollution.