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Several cities are facing an increasing flood risk due to the coupled effect of climate change and urbanization. Non-structural protection strategies, such as Early Warning Systems (EWSs), have demonstrated significant potential in mitigating hydraulic risk and often become the primary option when the implementation of structural measures is impeded by the complexities of urban environments. This study presents a new EWS designed specifically for fluvial floods in the city of Palermo (Italy), which is crossed by the Oreto River. The system is based on the preliminary definition of various Flood Event Scenarios (FESs) as a function of typical precursors, such as rainfall forecasts, and antecedent wetness and river flow conditions. Antecedent conditions are derived from real-time water stage observations at an upstream river section, while rainfall forecasts are provided by the Italian National Surveillance Meteorological Bulletins with a preannouncement time of up to 36 h. An innovative feature of the system is the use of rainfall Depth–Duration Thresholds to predict the expected hydrograph peak, significantly reducing warning issuing times. A specific FES, immediately accessible from a pre-built library, can be linked to any combination of precursors. Each FES predicts the timing and location of the first points of flooding; flood-prone areas and water depths; and specific hazard maps for elements typically exposed in cities, such as people, vehicles, and buildings. The EWS has been tested on a historical flood event, demonstrating satisfactory accuracy in reproducing the location, extent, and severity of the flood. [ABSTRACT FROM AUTHOR]

The floods of the Lahdar River cause repeated inundations and damage to road infrastructures, particularly crossing structures in the territorial center of Had Msila. Our study involved the application of various methods to estimate flood flows for different return periods along the Lahdar River. The selected flows were chosen after a comparative analysis of values calculated by the different methods used. These results served as the basis for hydraulic modeling aimed at assessing water levels to establish risk zone mapping. This step is crucial in flood risk assessment. Two main approaches were distinguished: hydrometeorological methods, based on regional parameters derived from rainfall data, and empirical methods, used in the absence or with limited data on flood flows in a given region. Hydraulic modeling was carried out using two software programs: a Geographic Information System (GIS) such as Arc-GIS, and a specific river modeling software like Hec-Ras, allowing for the numerical representation of the natural state of the territory. The results obtained serve as the foundation for all river hydraulic modeling, thereby facilitating flood prediction and hydrological risk management in floodplains. Modeling Lahdar River floods in the studied sections enables the prediction of flood risk and its impacts on constructions and infrastructure in the Had Msila Center. [ABSTRACT FROM AUTHOR]

This paper explores the use of the rain-on-grid (or direct rainfall) method for flood risk assessment at a basin scale. The method is particularly useful for rural catchments with small vertical variations and complex interactions with man-made obstacles and structures, which may be oversimplified by traditional hydrologically based estimations. The use of a hydrodynamic model solving mass and momentum conservation equations allows the simulation of runoff over the watershed at a basin scale. As a drawback, more detailed and spatially distributed data are needed, and the computational time is extended. On the other hand, a smaller number of parameters is needed compared to a hydrological model. Roughness and rainfall loss coefficients need to be calibrated only. The direct rainfall methodology was here implemented within the two-dimensional HEC-RAS model for the low-land rural, and ungauged, watershed of the Terdoppio River, Northern Italy. The resulting hydrographs at the closing section of the watershed were compared to synthetic design hydrographs evaluated through pure hydrological modelling, showing agreement on the peak discharge values for the low-probability scenarios, but not on the total volumes. The results in terms of water depth and flow velocity maps were used to create flood hazard maps using the Australian Institute for Disaster Resilience methodology. The Index of Proportional Risk model was then adopted to generate a basin-scale flood risk map, by combining flood hazard maps, damage functions for different building-use classes, and the value of reconstruction and content per unit area. [ABSTRACT FROM AUTHOR]

Flood persist as an acute problem requiring resolution because their recurring annual incidence. A body of research suggests that an effective policy approach can reduce the severity of such disasters. Our eneavor aims to assess policy direction of the government concerning flood management, particularly in urban areas. To achieve this, we srcutinize various written materials and documents connected to flood control administration in Indonesia. Our comprehensive review, focusing on the latest flood mitigation implementations, will drive recommendations for adopting a governance approach in flood management. These recommendations will derive from findings of our review. To lessen the risk of flooding, the government mjust establish a robust foundation, both strategically and tactically. [ABSTRACT FROM AUTHOR]

The latest report by the Intergovernmental Panel on Climate Change (IPCC) warns of an increase in heavy rainfall events due to global warming and climate change, which can result in significant economic costs for insurance companies and businesses. To address this challenge, insurance companies are focusing on developing new risk management strategies and offering new products such as flood insurance. However, the article argues that effective and feasible coordination shortens recovery time and can therefore drastically reduce the financial costs of a crisis—that is, the insurance costs. The paper analyses the deficit in crisis management during heavy rain events in Germany, based on the 2021 Ahr valley flood. The analysis is conducted based on document analysis and interviews and focuses on three areas of deficit: coordination between crisis staffs and (1) civil society, (2) emergency responders, and (3) political leaders. The paper highlights the importance of coordination during a crisis, which can help to address the crisis more efficiently and effectively, minimise damage and get communities back on their feet faster. The paper recommends policy changes to improve interface management and disaster management coordination. [ABSTRACT FROM AUTHOR]

The prime challenges limiting efficient flood management, especially over large regions, are concurrently related to limited hydro-meteorological observations and exorbitant economics with computational modeling. Reanalysis datasets are a valuable alternative, as they furnish relevant variables at high spatiotemporal resolutions. In recent times, ERA5 has gained significant recognition for its applications in hydrological modeling; however, its efficacy at the inundation scale needs to be understood. The advent of "global flood models" has ensured flood inundation and hazard modeling over large regions, otherwise obscure with regional models. For the first time, the present study explores the fidelity of ERA5 reanalysis at the inundation scale over the Mahanadi River basin, a severely flood-prone region in India. The biases in the discharges within ERA5 are ascertained by comparing them with station-level data at the nascent and extreme levels (i.e., 95th and 99th percentiles). Later, ERA5 is fed to LISFLOOD-FP, an acclaimed global flood model, to reenact the 2006, 2008, 2011, and 2014 flood events. Hit rates exceeding 0.8 compared to MODIS satellite imageries affirm the suitability of ERA5 in accurately capturing flood inundation. Distributed design discharges for 50 yr and 100 yr are derived using a set of extreme value distributions and fed to LISFLOOD-FP to derive design flood inundation and hazards in terms of both "depth" and "product of depth and velocity" of flood waters. Results derived from the study provide vital lessons for efficient land-use planning and adaptation strategies linked to flood protection and resilience. [ABSTRACT FROM AUTHOR]

Despite water shortages and infrequent rainfall in arid and semi-arid areas, their recent floods show that flooding tends to be more severe and life-threatening. However, flooding is a poorly understood natural hazard in arid and semi-arid areas and its management needs to address a set of challenges, some of which are unique to these zones. Hence, it is of great demand to develop a comprehensive understanding of Flood Risk Management (FRM) difficulties and needs that are significant in these regions. This review paper aimed to understand the current state of FRM in arid and semi-arid areas and to explore challenges existing in FRM of these zones, based on the authors' experiences from practice-based research. The study identified four main classes of challenges: (i) regional features and flood characteristics, (ii) operational challenges, (iii) technical challenges, and (iv) management/organizational challenges. It was then concluded that these FRM challenges are multidimensional and coupled together. After discussing the challenges, the study addressed requirements and provided an outlook on solutions, further improvements, and possibilities for FRM in these regions. [ABSTRACT FROM AUTHOR]

Given that the primary cause of flooding in Ontario, Canada, is attributed to spring floods, it is crucial to incorporate temperature as an input variable in flood prediction models with machine learning algorithms. This inclusion enables a comprehensive understanding of the intricate dynamics involved, particularly the impact of heatwaves on snowmelt, allowing for more accurate flood prediction. This paper presents a novel machine learning approach called the Adaptive Structure of the Group Method of Data Handling (ASGMDH) for predicting daily river flow rates, incorporating measured discharge from the previous day as a historical record summarizing watershed characteristics, along with real-time data on air temperature and precipitation. To propose a comprehensive machine learning model, four different scenarios with various input combinations were examined. The simplest model with three parameters (maximum temperature, precipitation, historical daily river flow discharge) achieves high accuracy, with an R2 value of 0.985 during training and 0.992 during testing, demonstrating its reliability and potential for practical application. The developed ASGMDH model demonstrates high accuracy for the study area, with a significant number of samples having a relative error of less than 15%. The final ASGMDH-based model has only a second-order polynomial (AICc = 19,648.71), while it is seven for the classical GMDH-based model (AICc = 19,701.56). The sensitivity analysis reveals that maximum temperature significantly impacts the prediction of daily river flow discharge. [ABSTRACT FROM AUTHOR]

Extreme weather events, such as heavy rainfall, are being increased by climate change in various regions, and such events often cause floods. This study examined the trends and variability of extreme rainfall indices using daily rainfall data (1981–2023) from three study sites at different socio-economic development spectra in Vhembe District, Limpopo Province, South Africa. The analyses focus on indices such as the annual total rainfall from wet days (PRCPTOT), the maximum number of consecutive dry days (CDD) and wet days (CWD), annual maximum 1-day and 5-day rainfall (RX1 day and RX5 day), the Simple Daily Intensity Index (SDII), the number of days exceeding varying amounts of precipitation (R10, R20, R40) and the annual number of wet days with rainfall greater than the 95th and 99th percentile (R95p and R99p) of the 1981–2023 daily rainfall. We discuss the observed trends in extreme rainfall indices in light of the actual flood occurrences to establish linkages. Several statistically significant and marginal changes in extreme rainfall trends were identified and provided key insights into reported flooding events in the district—flooding episodes were mainly attributed to the significant increases in total precipitation (PRCPTOT) and rainfall exceeding the 99th percentile of daily rainfall (R99p). Other significant contributors were declining CDD and increasing RX1day at Duthuni, increasing R40 at Musina as well as increasing R1 and declining CDD at Sane. However, the low altitude, urbanization, poor waste management and inadequate drainage systems were among the key non-climatic drivers of flood risk across the study sites, but these warrant further investigation. The complex interplay between climatic and non-climatic drivers of flood risk underscores the importance of localized climate studies and the need for adaptive strategies to minimize loss and damage. Overall, this research provides valuable insights into localized extreme rainfall trends, which are essential for developing site-specific flood mitigation and adaptation strategies. However, such initiatives require placing vulnerable communities at the centre in order to develop solutions that are locally led and relevant.

Current forecasts estimate that almost 68% of the global population will be living in urban centers by 2050. As a result, the increase in impermeable surface area can result in severe hydrological impacts, such as the increase in surface runoff and the frequency of floods and their magnitude. Thus, this work analyzes the performance of the hydrodynamic model HEC-RAS for assessing the extent of flood-prone areas, using two digital terrain models (DTM) with different spatial resolutions (5 and 0.50 m). Four different computing intervals (1, 15, 30, and 60 s) were adopted aiming to evaluate the simulations outputs performance. Additionally, reported data by the civil defense are used for calibration and validation. In general, the model showed to be a powerful tool in the identification of susceptible areas to urban flooding. The simulated results in this work provide crucial geographic information when identifying spots with the highest risk of flooding, which should receive priority attention during such events. The simulations with a spatial resolution of 5 m showed the flood maps with the largest coverage of the flooded points (278 points out of 286—97.20%), within the shortest computation times. We highlight that the more refined DTM derived from spatial images did not produce the best flood simulation compared to the DTM with a spatial resolution of 5 m derived from orthoimages. [ABSTRACT FROM AUTHOR]

Copyright of Tikrit Journal of Engineering Sciences 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.)

The study of flood risks has a fundamental role in ensuring the safety of cities near rivers and drawing up plans to protect them during future floods. This study aims to manage potential flood risks, and Tikrit city was used as a case study. The daily discharge of the Tigris River in the study area was provided by the Iraqi Ministry of Water Resources from 2019 to 2022. The HEC-RAS software was utilized to build a 2-D flood model to simulate potential flood scenarios. First, the model was calibrated by adjusting the value of Manning's coefficient (n), and it was found that n = 0.031 reflects the nature of the region because the Nash-Sutcliff Error (NSE) was 0.93. Then, the efficiency of the 2-D flood model was verified by comparing the model’s results with the study area’s satellite images, and the results showed a great match. Following that, the 2-D model was used under different flooding scenarios. The results showed that the size of areas exposed to flooding increased with the discharges passing through the Tigris River. For instance, increasing the discharge to 800m3/s increased the flooded areas by 13.7%, while increasing the discharge to 1500 m3/s increased the flooded areas by 90.7 % compared to the river’s normal flow. Also, the results showed that the eastern regions of the riverbanks are more vulnerable to flooding than the western side because the ground levels are low on the eastern side compared to the western part of the riverbanks.

Geohazard risk is high in Arab countries due to ineffective disaster preparedness measures, mismanagement, lack of public awareness, inadequate funding and lack of stakeholder support. One such country is Egypt, which is hit by floods every year that cost lives and bring the economy to a standstill. Moreover, not much has been done to map flood-prone areas. In this paper, flood susceptibility modelling was evaluated in the Ras Gharib region of Egypt using two effective techniques machine learning techniqueMLT (Support Vector Machine (SVM)) and deep learning methodDL (Convolutional Neural Networks (CNN)). Thirteen flood related factors and flood inventory layer were prepared to construct these models. Validation was performed with 30% of the flood locations where receiver operating characteristic (ROC) curves showed that the deep learning technique (CNN) gave a prediction accuracy of 86.5% (high performance), while the MLTs (SVM) gave 71.6% (medium performance). The results show that CNN provides 17% better than SVM which indicates a powerful and accurate model in flood susceptibility mapping. Results were confirmed using the Astro Digital images shortly after the 2016 flood, in which the CNN model provides a good agreement. [ABSTRACT FROM AUTHOR]

Traditional flood risk paradigms and associated strategies are no longer sufficient to address global flood adaptation challenges due to climate change and continued development in floodplains. The current flood adaptation approach is failing to take advantage of the benefits provided by intact ecosystems and perpetuates social and economic inequities, leaving those who are most vulnerable at highest risk. Rooted in the experiences of the United States, we propose a new framework, the Flood Adaptation Hierarchy, which prioritizes outcomes into six tiers. Overall, the tiers distinguish between nature and nature-based solutions, with preference given to natural ecosystems. The most important outcome in our hierarchy is to avoid risk by protecting and restoring natural floodplains; next, eliminate risk by moving communities away from danger; and then to accommodate water with passive measures and active risk reduction measures. We include, but deprioritize, a defense of community assets using nature-based engineering and hardened engineering. Throughout the hierarchy, we provide guidance on the equity considerations of flood adaptation decision making and highlight "impacts," "resources," and "voices" as important equity dimensions. Implementing the framework through an iterative process, using justification criteria to manage movement among tiers, alongside equity considerations, will support adaptation to changing environmental and social conditions and contribute to risk reduction at scale. Though this approach is focused on U.S. flood management and adaptation, prioritizing risk reduction, elimination of risk, and accommodation of hazards over the defense against threats not only has global applicability to flood adaptation, but should also be evaluated for applicability to other climate-driven challenges. [ABSTRACT FROM AUTHOR]

In September 2014, Kashmir witnessed a catastrophic flood resulting in a significant loss of lives and property. Such massive losses could have been avoided if any structural support such as dams were constructed in the Jhelum basin, which has a history of devastating floods. The GIS-based multicriteria analysis (MCA) model provided three suitability zones for dam locations. The final suitable dam sites were identified within the highest suitability zone based on topography (cross-sections), stream order, high suitable zone, minimum dam site interval, distance from roads, and protected area distance to the dam site. It was discovered that 10.98% of the total 4347.74 km2 area evaluated falls in the high suitability zone, 28.88% of the area falls in the medium suitability zone, and 60.14% of the area falls in the low suitability zone. Within the study area, four viable reservoir sites with a holding capacity of 4,489,367.55 m3 were revealed. [ABSTRACT FROM AUTHOR]

The modelling and management of flood risk in urban areas are increasingly recognized as global challenges. The complexity of these issues is a consequence of the existence of several distinct sources of risk, including not only fluvial, tidal and coastal flooding, but also exposure to urban runoff and local drainage failure, and the various management strategies that can be proposed. The high degree of vulnerability that characterizes such areas is expected to increase in the future due to the effects of climate change, the growth of the population living in cities, and urban densification. An increasing awareness of the socio-economic losses and environmental impact of urban flooding is clearly reflected in the recent expansion of the number of studies related to the modelling and management of urban flooding, sometimes within the framework of adaptation to climate change. The goal of the current paper is to provide a general review of the recent advances in flood-risk modelling and management, while also exploring future perspectives in these fields of research. [ABSTRACT FROM AUTHOR]

Owing to climate change, torrential rains and typhoons have become more frequent. However, to cope with this threat, conventional flood management suffers from limitations and difficulties because of the practice of uniform flood prevention measures being applied to all stream sections according to river grade classification. A wide array of measures should be considered to differentiate flood protection targets: adaptive flood management strategy is one such effort. One obstacle, however, to introducing such a measure is lack of clarity over how to divide quantitatively the degree of risk from flooding. In this study, we undertook quantitative risk assessment to determine the risk level in a riparian zone. We compared our results with statistically derived societal risk limits to determine whether the risk level was acceptable within the framework of the tolerance risk limit. We found that the flood risk could be reduced through adaptive flood management. [ABSTRACT FROM AUTHOR]

Many coastal cities in developing countries are at the risk of flooding due to a progressive increase in the built-up areas and poor management of storm water. The flooding situation in coastal cities gets accentuated further due to climate-induced natural disasters such as cyclones and climate change-induced sea-level rise that adversely impact the city's natural drainage potential. This study developed a composite urban flood risk index consisting of three sub-indices and 20 key natural, physical, social, and economic influencing variables for a coastal city (i.e., Cuttack) in eastern India, the intensity of storm run-off being one among the many. The intensity–duration–frequency curve developed shows that the city can experience floods with a peak discharge of 1320 cubic metre per second every alternate year for a rainfall intensity of 2-h duration. The urban flood risk index computed for all the city wards shows that out of the 59 wards, only one ward has low flood risk (index value < 0.40) and 20 wards are at high risk (index value 0.55 and above) from the urban flood. Thereafter, factors leading to high risk due to urban floods were identified and the institutional capacities available with the urban utility for fighting floods analysed. [ABSTRACT FROM AUTHOR]

Flooding disaster is one of the major challenges posing serious threats to the human society. This study assesses residents’ participation in flood risk reduction in Osogbo, Osun State, Nigeria, with a view to enhancing a better managed urban environment. The study utilized both field observations and questionnaire. A total of 270 pretested structured questionnaires were administered systematically on every 5th household head in the study area to solicit information on their environmental characteristics to compute the Residents’ Satisfaction Index (RSI) on a 5-point Likert scale. Data collected were analyzed using descriptive and inferential statistics. Findings revealed that the RSI for Public Sensitization had the highest mean weighted value of 2.97 while flood dam control had the lowest mean weighted value of 1.02. The results of partial correlation computed revealed that a positive significant correlation existed between residents’ participation and income (r = 0,271, p = 0.000) while a negative significant correlation existed between community participation and length of stay (r = -0.127, p = 0.0046). The study concluded that residents’ environmental attributes and perceived causes of flood disaster were the major determinants of the community participation in flood disaster risk reduction. In addition, there is need for training of residents on afforestation practices to enhance greater community participation in flood disaster risks management. [ABSTRACT FROM AUTHOR]

Incessant and unchronological development of urban areas at a quick pace in the floodplains of the rivers and into the unoccupied areas of the waterways has augmented the chances of the flood risk. The main aim of the present study is to examine the implications of urbanization on the flood events of Surat city and its surrounding region (Gujarat, India), the lower part of the Tapi river basin. The expansion of urban area between the years 1968 and 2006 has been evaluated from topographic maps and a remote sensing satellite image. The flood risk analysis for two different years along with their land-use pattern has also been derived. The result shows that almost the same amount of flood levels have caused more damage in the flood year 2006 than the flood year of 1968 which is due to the urbanization growth. Other than the natural processes, traditional developments of the landscape with impervious obstructions have been observed as the major driver for aggravating the flood risk. Detention ponds were suggested and the flood diversion map has been prepared using the Spatial Analyst functions in ArcGIS software to lessen the growing urban flood risk. [ABSTRACT FROM AUTHOR]

Flooding remains the most common disaster in Nigeria since its first occurrence in 1948. While the subject of flood management has enjoyed sufficient attention in the literature, the primacy of inter-agency collaboration in managing the effects of flood emergencies and in implementing flood management-related policies remain less explored. This forms the basis for this article. The qualitative research approach was adopted to elicit information from ten key informants from federal, state and local government agencies directly involved in flood management. Three states from three of the six geo-political zones with the highest records of floods were purposively selected. Besides, publications/reports and other secondary materials were reviewed to generate secondary data, while a conceptual framework was woven around the importance of government institutions in implementing public policy. Results show that despite the appreciable level of collaboration among the government institutions/agencies in managing floods in the country, such collaboration is yet to translate into improved service delivery. Identified causes include low institutional capacity, inadequate funding and bureaucratic corruption. Based on these findings, it was recommended that institutions/agencies should be repositioned to play more active roles in Nigeria's flood management system and implement related public policies. If this is done, it would save the country from the socio-economic effects of flood disaster, which has placed a burden on government spending and infrastructural development. [ABSTRACT FROM AUTHOR]

Residents along the shoreline of the Orashi River have yearly been displaced and recorded loss of lives, farmland, and infrastructures. The Government’s approach has been the provision of relief materials to the victims instead of implementing adequate control measures. This research employs Shuttle Radar Topographic Mission and Google Earth imagery in developing a 3D floodplain map using ArcGIS software. The result indicates the drainage system in the study area is dendritic with catchment of 79 subbasins and 76 pour point implying the area is floodplain .Incorporating the 3D slope which reveals that> 8 and <8 makes up 1.15% and 98.85% of the study area respectively confirms the area is a floodplain. Aspect indicate west-facing slope are dark blue, 3D hillshade indicate yellow is very low area and the high area is pink and also the buffer analysis result reveals waterbodies reflecting blue with an estimated area of 1.88 km², yellow indicate 0.79 km² of the shoreline, red indicate 0.81 km² of the minor floodplain and pink contain 0.82 km² with the length of 32.82 km. The result from google earth image in 2007 indicate absent of settlement, 2013 indicate minimal settlement and 2020 indicate major settlement in the study area when correlated with 3D Floodplain mapping before and during the flood in other to analyze and manage flooding for further purpose and the majority of the area are under seize with flood like in 2020. Therefore, Remote Sensing and GIS techniques are useful for Floodplain mapping, risk analysis for control measures for better flood management. [ABSTRACT FROM AUTHOR]

Abstract Flood risk reduction can be provided by interventions such as raising land or constructing flood defences. This paper introduces an approach to optimise the selection of risk reduction strategies. It expands existing economic optimization approaches for flood defences, by introducing (largely) analytical formulations to include the effects of approaches to mitigate flood consequences. The method considers the size of the protected area and associated damages, the costs and dimensioning of interventions and the likelihood of flooding. It is applied in several practical cases. Within the context of this economic model, we conclude that a system of flood defences is more economical than a landfill for larger areas. Fills are preferred for small areas and/or for low costs. A combination of strategies is preferred when the value protected by the flood defence is low compared to the value protected by the fill, or when the high value development is relatively small in size. The sensitivity of outcomes to the choice of the main input parameters is presented, as well as implications of the results and selection of strategies in developing and developed countries. Overall, this approach supports decision makers in developing effective strategies to manage and reduce flood risk.

The modelling and management of flood risk in urban areas are increasingly recognized as global challenges. The complexity of these issues is a consequence of the existence of several distinct sources of risk, including not only fluvial, tidal and coastal flooding, but also exposure to urban runoff and local drainage failure, and the various management strategies that can be proposed. The high degree of vulnerability that characterizes such areas is expected to increase in the future due to the effects of climate change, the growth of the population living in cities, and urban densification. An increasing awareness of the socio-economic losses and environmental impact of urban flooding is clearly reflected in the recent expansion of the number of studies related to the modelling and management of urban flooding, sometimes within the framework of adaptation to climate change. The goal of the current paper is to provide a general review of the recent advances in flood-risk modelling and management, while also exploring future perspectives in these fields of research.

The term flooding is often associated with a stream overflow or a marine flood, runoff-floods is rarely considered, and today suffers from a lack of knowledge and control of the phenomenon. This paper, presents a geographic information system iRIP@ – Flooding by Intense Pluvial Runoff (French acronym), which is a new tool to mapping flooding by runoff as a tool for decision-making by mapping runoff flooding in Gareat El Taref catchment (Northeast Algeria), with identifying the area of production, transfer and accumulation of flood.

Flooding has become one of the most rapidly growing types of natural disaster that has spread around the globe. It is one of the major natural hazards in many countries and mostly affected in the low-lying or flood prone areas. In order to minimize loss of life and economic losses, a detailed and comprehensive decision-making tool is necessary for both flood control planning and emergency service operations. In this paper, we demonstrate our research design for mobile based decision support of Flood Early Warning System (FEWS). We outlined four research objectives. Firstly, critical criteria for flood risk assessment will be identified and the second step will involve develop measurement model for relative flood risk using Geographic Information System (GIS), Multi Attribute Decision Making (MADM) and data mining technique. In the third objectives, the holistic architectural design is developed by incorporating the communication technology and other related ICT requirements for the mobile decision support. The fourth objective is to validate the mathematical model and architectural design. Case study approach is chosen in order to understand the flood event and validate the decision support model. Following well-defined procedures, flood maps were drawn based on the data collected from expert responses to a questionnaire, the field survey, satellite images, and documents from flood management agencies. It anticipates that by integrating of mathematical model, GIS and mobile application in flood risk assessment could provide useful detailed information for flood risk management, evacuation, communication. The decision support design from this study is perhaps to improve the warning system and contribute to reduction of casualties. [ABSTRACT FROM AUTHOR]

The importance of governance rearrangements (reassignment of positions, roles, and responsibility among actors in governance processes) and their implications on flood risk management has gained currency in evaluative environmental governance literature. However, much work has concentrated on building and applying frameworks to evaluate impacts of decentralisation, such that frameworks to evaluate impacts of recentralisation are still lacking. This paper uses the case of Bwaise III informal settlement in Kampala, Uganda, to assess the impacts of local government rearrangements on flood mitigation. We adapted a Water Governance Assessment Framework and conducted 22 in‐depth interviews with stakeholders, searched documentary sources, and carried out transect walks. We generated qualitative data on stakeholder experiences and perceptions regarding governance quality and flood mitigation prereform and postreform. The data were analysed using thematic content analysis to produce a scoreboard measuring changes in governance dimensions against progress in flood mitigation. In a follow‐up survey, 24 structured interviews were conducted to validate the data. Results show that the rearrangements led to time and cost savings, increased revenue, and sped up the implementation of flood management strategies and measures. The findings can be useful to policymakers at the interface of governance and flood management. [ABSTRACT FROM AUTHOR]

'Sponge City' is the term used to describe the Chinese government's approach to urban surface water management. The concept was conceived in 2014 in response to an increasing incidence of urban flooding or water-logging in Chinese cities. While ambitious and far-reaching in its aim (of decreasing national flood risk, increasing water supply and improving water quality), the initiative must be implemented by individual subprovincial or municipal-level government entities. Thus, while the concept is similar to sustainable drainage systems (SuDS) in the UK (or low-impact development (LID) in the USA), it is developing with different regional characteristics, and during continuing rapid urbanization. Indeed, the increasing use of national rather than international examples of best practice reflects a growing body of knowledge that has evolved since the start of the Sponge City initiative. In this paper, interpretation and development of the national Sponge City guidelines are assessed for the Ningbo Municipality, an affluent and rapidly expanding city on China's low-lying east coast. While climate, geology and socio-economic factors can all be seen to influence the way that national guidelines are implemented, project financing, integration and assessment are found to be of increasing influence. This article is part of the theme issue 'Urban flood resilience'. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell 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.)

With climate change and rapid urbanization, the prevalent flood disasters and associated risks in urban areas have become increasingly crucial global issues. Risk assessment is a basic step in flood management and mitigation, while flood management is important to achieve risk mitigation. A comprehensive assessment framework considering both pre- and post-disasters that can address flood risk is lacking. Therefore, this study developed an integrated framework by combining the assessments of flood risk and flood management performance. Taking Beijing and Munich as research objects, this study generated flood risk maps at the grid scale for the period 2000–2020 and comparatively assessed the performance of various flood management measures. The urban flood risk in Beijing showed an increasing trend and then a decreasing one from 2000 to 2020, exhibiting high spatial characteristics in the southeast and low spatial characteristics in the northwest. The flood risk in Munich showed an overall decreasing trend, with strong spatial characteristics in the center area but less so in suburban areas. The shift from low to high urbanization levels was the major factor increasing the regional flood risk. Therefore, effective flood management measures in urban areas could potentially mitigate the flood risk, and Munich had a higher flood management performance owing to its well-developed flood management systems. This study provides a new framework for flood risk assessment and resilient flood management and contributes to the development of practical measures for disaster mitigation in rapidly-developing urban areas. • An integrated assessment framework of urban flood risk and management is proposed. • The transition from low to high urbanization is the major factor to increase flood risk. • Flood resilience management is an effective way to reduce flood risk. • The research proposed suggestions for resilience building in rapid urbanization areas. [ABSTRACT FROM AUTHOR]

The social–ecological status of rivers is particularly pronounced during extreme flood events. Extreme floods are a substantial threat to people, infrastructure, and livelihoods. Efforts to address the threats of extreme floods are aligned largely with social values of flood risk mitigation, flood preparation, and avoidance of loss. However, extreme floods are also a fundamental driver of river ecosystems, aligned with ecological (biophysical) values of event effectiveness, river change, disturbance, biotic response, and heterogeneity. A survey of the public perceptions of extreme floods revealed that participants generally understood the ecological values of extreme floods through concepts of naturalness, climate change, and knowledge production. However, participants had less understanding of how river integrity might influence the response of rivers to extreme floods. Resilience can be used as a framework for uniting the social and ecological values of extreme floods because it embodies a common language of change, disturbance, and adaptation and complements the socially dominated discourse of risk and emergency management. Three strategies are given for river scientists to frame ecological values in parallel with the paradigms of the socially dominated discourse of extreme floods: be prepared to act following an extreme flood disaster, learn and use the language of the flood risk and emergency management sector, and undertake assessments of the ecological values of extreme floods to highlight the threats to those values that may occur with climate change and river modification. [ABSTRACT FROM AUTHOR]

This paper presents a fuzzy expert system-based framework for flood management in Saudi Arabia that helps the civil defense (CD) authority in both preparing their flood management capabilities and responding to scalable levels of flood risk. One of the most important type of flood management capabilities is training capabilities, the adequacy of training capabilities of emergency responders is a critical factor that influences on flood risk management, even considering other types of capabilities such as equipment and infrastructure. However, due to the lack of adequate training capabilities in place to address dynamic change of flood risk and vulnerabilities in some areas, emergency readiness for floods has been critically affected and resulted in ineffective response and mutual aid. Here, the study aimed to aid decision-makers in the Saudi CD Authority to reduce inappropriate readiness of training capabilities in some critical zones and maintain the levels of readiness using a proposed fuzzy expert system-based framework, which is named the capability evaluation and readiness (CER) framework. The developed CER framework includes a new fuzzy expert system, which is named the intelligent capability evaluation and readiness (ICER) system. CER framework uses three key elements for readiness evaluation and addressing needs related to training capabilities; the records of the provided training and exercises; the targeted standard and policy of readiness and mutual aid; and risk assessment of each zone and existing hazard and vulnerability (HV) factors within a zone. The results of evaluation by interviews indicted high agreement on effectiveness and productivity of the CER framework, however, it is recommended that additional stakeholders are included in order to have comprehensive information regarding others HV factors. In addition, questionnaires shown that more than 60% of the respondents believe that the ICER system is an effective tool for flood response, however, regarding the readiness of the training capabilities, more that 17% of the respondents believe that the ICER system is not effective tool to improving the readiness of the training capabilities. [ABSTRACT FROM AUTHOR]

The sharp end of climate change is being, and will continue to be, experienced at the local and personal scale. How changing patterns of hazards interplay with local landscapes is an important focus of risk management, both in understanding how place-based risk is perceived and in identifying how local populations would like these risks to be managed. In this study we focus on the object of hazard and examine how different meanings associated with water and waterbodies relate to flood risk perception and preferences for flood management strategies. We present analysis of a mixed methods study with survey data (n = 707) of residents in four coastal towns in France, South Africa and UK presented alongside an in-depth study of the two French towns (semi-structured interviews n = 15 and document analysis). Our analysis unpacks the significance of relationships between the meaning of water in general, and the meaning of specific water bodies, to flood risk perceptions. Our findings indicate that general water meaning is more reliably related to flood risk perception than specific waterbody meaning, where waterbody meanings are significant for flood risk perception, positive identification with rivers relates to reduced flood risk perception. We also find that the meanings associated with water and waterbodies relate to specific preferences for different types of flood management, including insurance and local taxation. The implications for landscapes undergoing rapid change, for example as a result of changing climate and hydrological regimes, are discussed. In particular, we highlight how infrastructure interacts with sense of place in communities undergoing rapid social–ecological change and how understanding this interplay can help in the design of more fully supported adaptation strategies. [ABSTRACT FROM AUTHOR]

Rivers are the lifeblood of many cities, but flood risk is projected to increase due to urbanisation and climate change. Better floodplain management in and near urban areas is required to produce the New Urban Agenda’s ‘just, safe, healthy, accessible, affordable, resilient and sustainable cities’. Many jurisdictions are looking to move or keep people out of human-constructed residential ‘niches’ on hazardous floodplains, but this has proved difficult to achieve. Our historical case studies of colonial societies in ancient Rome, as well as on the Yangtze, Mississippi and Brisbane rivers, show the deep roots of many contemporary flood risk issues, such as failures of risk perception related to recent settlement, the moral hazard of spending on flood defence infrastructure, the creeping nature of floodplain encroachment into ‘niches’ of perceived protection created by structural interventions, the need for a central, ‘whole of river’ approach, and the difficulties of implementing this approach locally. These case studies also suggest solutions, including the adoption of Indigenous perspectives, benefits to incentivise local actors and a historical education strategy to increase appetite for more sustainable flood risk mitigation. [ABSTRACT FROM AUTHOR]

Abstract: In recent decades, there has been a significant increase in economic losses caused by flood events on the coastal region of south‐eastern Spain. The increase of extreme rainfall events forecast by the climate change models is currently not reflected in the statistics which suggests that the principal cause is due to the exposure experienced within the past 40 years. Consequently, it is interesting to evaluate the effect of urban growth in flood‐prone areas and the role played by government institutions in mitigating the increase in exposure. For this study, the cadastral information and the hydrological modelling data for the return periods of 10, 50, 100 and 500 years were used. This allows high‐resolution spatial–temporal results to be obtained that show one of the most significant growths in exposure in Spain and Europe, as well as the low efficiency that risk mitigation measures have had. [ABSTRACT FROM AUTHOR]

Abstract: There are several mapping products available that depict areas susceptible to groundwater flooding; however, they are not comparable in detail to the risk maps developed for fluvial, tidal and surface water flooding that are used by risk management authorities. This paper reports on a new approach to groundwater flood risk mapping for unconfined Chalk aquifers. This approach recognises the synergies between surface water flooding and groundwater flooding once groundwater has emerged at the surface. The volume of groundwater at the surface is modelled by identifying the zone of groundwater emergence and calculating the rate of emergence using a Darcy approach. Flow is then routed using a bespoke two‐dimensional hydraulic model to give the depth and extent of groundwater flooding. These groundwater emergence and routing maps are calibrated on measured groundwater flow and observed flood extents. The maps are anticipated to be used to plan for and manage future groundwater flooding events. [ABSTRACT FROM AUTHOR]