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Abstract Decision making under deep uncertainty (DMDU) approaches are well‐suited for making decisions about infrastructure to manage flooding exacerbated by climate change. One important system for climate resilience and flood management is green infrastructure, which refers to a network of natural and semi‐engineered areas that provides ecosystem functions. Green infrastructure is often characterized as a low‐regret strategy with multiple co‐benefits under uncertainty. These attributes enable green infrastructure to be an important adaptation strategy under DMDU frameworks for flood management. However, DMDU analyses that include green infrastructure are still relatively limited, perhaps due to computational or modeling complexity and other barriers. This paper identifies and reviews publications in the flood management literature that use DMDU frameworks and refer to green infrastructure adaptation strategies, in order to identify trends and inform future research. The reviewed publications are categorized according to a variety of performance metrics, climate change scenarios, DMDU metrics, and hydrologic modeling techniques, and represent several adaptation strategies applied to case studies on five continents using a range of data sources and assumptions. This paper highlights a number of solutions that can be employed to facilitate additional research at the intersection of these fields. Primary among these is the transparent documentation and use of open source models, methods, and data. Future research should also focus on communication among different stakeholders, particularly in ensuring definitions, assumptions, and data requirements are clear. These partnerships can facilitate effective application of robust strategies such as green infrastructure for urban adaptation to the effects of climate change.

Abstract Overbank flows occur in alluvial valleys during flood events when the conveyance of main channel of rivers is exceeded. Once floodplains are inundated and the so-called compound channel flow is observed, the faster flow in the main channel interacts with the slower flow in the floodplain featuring a much more pronounced 3D flow structure compared to single channel flow. These flow mechanisms comprise a shear layer near the interface, lateral momentum transfer and strong secondary currents due to the non-isotropic turbulence. This paper starts by giving an overview of the main flow mechanisms in compound channels pointing out the importance of taking into account the apparent shear stress generated between the main channel and the floodplain flows due to the interaction of these flows. A new simple model was developed to include the apparent shear stress concept as a correction of the Manning roughness coefficient of main channel and floodplains. The proposed method for predicting stage–discharge relationships was calibrated and validated by experimental data from several compound channel facilities. A significant improvement in prediction of the compound channel conveyance in comparison with the traditional methods was achieved.

Floods are one of the most dangerous natural disasters, causing great destruction, damage, and even fatalities worldwide. Flooding is the phenomenon of a sudden increase or even slow increase in the volume of water in a river or stream bed as the result of several possible factors: heavy or very long precipitation, melting snowpack, strong winds over the water, unusually high tides, tsunamis, or the failure of dams, gages, detention basins, or other structures that hold back water. To gain a better understanding of flooding, it is necessary to examine evidence, search for ancient wisdom, and compare flood-management practices in different regions in a chronological perspective. This study reviews flood events caused by rising sea levels and erratic weather from ancient times to the present. In addition, this review contemplates concerns about future flood challenges and possible countermeasures. Thus, it presents a catalogue of past examples in order to present a point of departure for the study of ancient floods and to learn lessons for preparation for future flood incidents including heavy rainfalls, particularly in urbanized areas. The study results show that ancient societies developed multifaceted technologies to cope with floods and many of them are still usable now and may even represent solutions and measures to counter the changing and increasingly more erratic weather of the present.

Older people are identified as a vulnerable group in disaster. There should be more focus on their capacities and needs. Yet, there are limited studies on flood knowledge, family support, and emergency response plans affecting older people's flood-management practices. The study aimed to examine the correlation between sociodemographic characteristics; knowledge of Disasters Resilience Family Program (KATANA), disasters, and floods; family support; and the emergency response plans in flood management. This study employed a quantitative approach and utilized a cross-sectional research design. It involved 105 participants selected using simple random sampling. The study found that (1) knowledge of KATANA, disasters, and floods remained relatively low; (2) older persons' practices before floods differed by age and gender, and practices after a flood varied by employment status; (3) family support for older people facing a flood was relatively poor; (4) emergency response plan vary based on education, gender, marital status, and family type; (5) older people with good knowledge of KATANA, disasters, and floods were 5.79 times more likely to be well-practiced in flood management than those who had not (OR = 5.79, p = 0.000). These findings suggest increasing older peoples' knowledge of KATANA, disasters, and floods through disaster-preparedness training and simulating government and civil society mitigation efforts to strengthen older individuals' disaster resilience. At the governmental level, detailed, comprehensive, and realistic actions in disaster management, especially targeted at older people, should be put in the New Disasters Rules for 2024 by the Indonesian National Disasters Management Agency. [ABSTRACT FROM AUTHOR]

Riparian woodlands prevent bank erosions, recycle minerals, sustain biodiversity, act as flow resistance on floodplains, and filter pollutants. The emergent trees characterize woodlands with different spacing arrangements that dictate flow resistance and longitudinal dispersion of the pollutants in compound channel flow. The single- and multistage compound channels exist in urban and natural watercourses with riparian and transplanted trees on different stages of the floodplain. This study numerically validates the planting of vegetation in lines on single- and multistage floodplains using a wall-modeled large-eddy simulation model. Post-validation, the focus of the study was to assess the hydrodynamic behavior and mixing around the floodplain and main channel section of different tested configurations. The approximation of flow structures for the various configurations of tree plantations shows stronger vortices with significant characteristic length scales for floodplains closer to the main channel. The intensity of the secondary current is higher for denser planted trees at junctions of floodplains. For higher flow events, drag force contributions for staged floodplains with trees on both stages are 45–41%, and trees on the top stage contribute 27-22% to the total frictional force budget. The subsequent investigation shows that the in-line trees geometrical configuration and spacing arrangement on the floodplain dictates flow resistance and longitudinal dispersion of the pollutants and contamination in channel flow. The results show that the overall reduction in discharge for floodplains with tree planting is 19.8–36.2% for single-stage and 10.4–23.6% for multistage compound channels. The longitudinal dispersion coefficients for each multi-zone model predict a 61% and 41% dispersion reduction, respectively, in single- and multistage floodplains with planted trees. Floodplains with denser tree spacing have a maximum zonal discharge reduction of 45% for a single-stage and 27.2% and 28.0% for multistage channels. These findings strongly suggest that the planting parameters of spacing-to-diameter ratio and floodplain geometry play a pivotal role in floodplain management from the perspective of contaminant dispersion and flood risk reduction during high-flow events. [Display omitted] • A wall-modeled large eddy is used to simulate in-line tree vegetation on the compound open channel floodplains. • The study discusses the flow structures for single and multistage compound channels with trees on the bank. • Drag force, discharge reduction, and dispersion coefficient in floodplains with and without in-line riparian woodlands are compared for flood scenario. • The study reveals that plantation and geometric parameters in channel flows affect flow resistance and pollutant dispersion in high-flow events. [ABSTRACT FROM AUTHOR]

There is no detailed information about the trend of vegetation changes under floodwater spreading (FWS) programs in arid areas. Here, vegetation cover and composition were monitored using 30 permanent plots along transects through 8 years (2012-2019) FWS program in central Iran's sandy clay loam soil. Vegetation evaluation was performed annually. At the end of the experiment, soil sampling was performed from the plots to study soil-vegetation relationships using principal component analysis (PCA). An area adjacent to the FWS area was also considered as a control. Based on the results, the FWS significantly changed the vegetation characteristics and improved some valuable species. The largest changes in vegetation occurred during 3-4 years of FWS. Cover and density of perennial species increased by 240% and by 144%, respectively. Also, cover and density of annual species showed a decrease of 23% and 46%, respectively after 8 years. Moreover, the cover and density of the forbs increased, while cover and density of the grasses decreased. Shannon richness and Margalef diversity indices increased in first 4-5 years and then showed a decrease during the last three years of FWS program. Based on the PCA results, clay, organic matter, soil moisture, saturation percent, porosity were correlated with cover/density/biomass of plant species after 8 years FWS program. Overall flood spreading caused changes in vegetation development, and managers should be aware of the greater undesirable change in vegetation in future as a result of continuing FWS. [ABSTRACT FROM AUTHOR]

This study assesses the potential downstream impacts in the event of a flood due to failure, either structural or operational, of the Grand Ethiopian renaissance dam (GERD). The following two failure scenarios were modeled as part of this study: Dam Break (DB) and MisGuided Dam Operation (MGDO) as a result of a false flood signature. The DB scenario shows that 40% of the intensively cultivated Gezira Plain would be inundated with average water depths of more than 10 m, resulting in catastrophic loss of highly productive farmlands, livestock, inhabitants, and infrastructure. This scenario did not model damage further downstream since for this magnitude flood it will require another flood routing model given the more complex geometry downstream of the Gezira Plain. In the MGDO scenario flood flows are lower and would have no impact on the Gezira Plain but would reach the High Aswan Dam (HAD) and fill it to its maximum allowable capacity for two and a half months and it would require emergency releases for more than 5 months. The required emergency releases from the HAD are expected to create significant flooding downstream. To accommodate the potential of extra releases from the GERD during flood events the operational rules for the HAD should be modified. However, providing more flood buffer at the HAD will limit the live capacity that is currently used for securing downstream flow requirements during drought periods. One of the expected impacts of increasing the flood buffer would be a reduction of the HAD's contribution to Egypt's GDP. Based on the results of this study the operational rules for the GERD and the HAD should be evaluated and possibly modified. [ABSTRACT FROM AUTHOR]

Accurate and reliable discharge estimation is considered vital in managing water resources, agriculture, industry, and flood management on the basin scale. In this study, five data-driven tree-based algorithms: M5-Pruned model-M5P (Model-1), Random Forest-RF (Model-2), Random Tree-RT (Model-3), Reduced Error Pruning Tree-REP Tree (Model-4), and Decision Stump-DS (Model-5) have been examined to measure the daily discharge of Govindpur site at Burhabalang river, India. The proposed models will be calibrated by daily 10-years time-series hydrological data (i.e., river stage (h) and daily discharge (Q)) measured from 2004 to 2013. In these models, 70% and 30% of the dataset were used for the training and testing stage for the reliability of the developed models. The precision of the models was optimized by investigating five different scenarios based on various time-lags combinations. Model's performance has been assessed and evaluated using five statistical metrics, namely, correlation coefficient (R2), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), Relative Absolute Error (RAE), and Root Relative Squared Error (RRSE). Results showed that Model-3 outperforms as compared to other proposed models. Machine learning models have been examined five scenarios of input variables during training and testing phases. In comparison of the Model-5 struggled in capturing the river's flow rate and showed poor performance in scenarios where R2 metric values ranged from 0.64 to 0.94. Therefore, it can be concluded that the RT model could be used as a robust model for sustainable flood plain management. [ABSTRACT FROM AUTHOR]

One of the important tools for watershed management and optimal decision making is the prioritization of sub-watersheds which can be effective in soil and water conservation and flood management. Hence, the purpose of this study is to investigate different methods of prioritization of sub-watersheds based on flood generation potential using physical, hydrological and co-managerial approaches in the Cheshmeh-Kileh Watershed, Mazandaran province, Iran. To do this, three approaches including physical criteria (i.e., application of game theory based algorithms), hydrological modeling (i.e., using HEC-HMS model) and co-managerial approach (i.e., employing the opinions of local residents, technical experts and policy makers) were used to prioritize sub-watersheds. Finally, the sub-watersheds were classified into three categories based on flood generation potential. The results showed that there is a difference between the results of co-managerial approach with physical and hydrological modeling approaches. According to the research findings, in physical and hydrological modeling approaches, prioritization of sub-watersheds depends on physical factors such as greater slope, area and less time of concentration. But in Integrated Watershed Management (IWM), in addition to the physical and technical aspects, economic, social, political and legal issues must be considered in decision making, which indicates the necessity of the application of co-managerial approach. Based on field observations, sub-watersheds that have been given first priority by co-managerial approach have a significant annual contribution in flood generation due to low vegetation density. In general, it can be said that physical and hydrological approaches consider only physical and geo-environmental parameters and cannot prioritize important issues such as economic, social and political factors that require the views of local stakeholders. [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]

This Classics Revisited/From the Archives paper summarizes the 1962 publication of Robert Kates regarding perceptions of the flooding hazard in LaFollette, Tennessee, and five other cities that were used for comparison. The influence of this work on improvements in flood hazards since 1962 are discussed, as well as suggestions as to how this work will continue to influence flood hazard management and mitigation. [ABSTRACT FROM AUTHOR]

One of the important relationships which are used in the estimation of river discharges and floods is Intensity-Duration-Frequency (IDF). The accuracy of this relation is dependent on the accuracy of its parameters which need to be found based on short-duration rainfall depths (such as 15, 30, 60 minutes, and so on) for a long term (i. e. 30 consecutive years). Unfortunately, only 24-hour rainfall depths are available in many rainfall stations in Iran. Various empirical relations are available to convert 24-hour rainfall depth to sub-daily. One of these methods is IMD and its accuracy in some regions is low. In this research, the IMD method was transformed into a single-parameter equation and then, this parameter is evaluated for some rainfall stations in Iran. To do this, maximum 24, 12, 6, and 3-hour rainfall depths were extracted and their frequencies were calculated using Weibull and Gumbel methods. Regional coefficients in the modified IMD method were estimated using a linear regression method. Although the power of the IMD method is 0.33, results showed that this parameter for the rainfall stations ranged from 0.28 to 0.35. To make more comparison, the IDF relation of Kordan’s watershed was calculated using the short-duration rainfall depth which was estimated using the modified IMD, and then, this IDF was compared to observed data and Ghahraman’s relation which is commonly used in Iran. The comparison showed that the modified IMD relation could estimate the short-duration rainfall data better than Ghahraman’s relation. After calibration of the modified IMD relation for various regions in Iran, the sub-daily rainfall depth can be obtained with high accuracy. [ABSTRACT FROM AUTHOR]

The vegetation grown on grasscretes along channelized rivers have been regularly mown in Hong Kong. However, no baseline information on the relationship between different mowing regimes and the biodiversity of such riverbed vegetation is available. We therefore carried out a manipulative experiment along a channelized river to test the effect of mowing frequency and intensity on the abundance and species richness of terrestrial biodiversity. We conducted point counts and transect counts to survey birds, butterflies and Odonates, night surveys for amphibians and reptiles, quadrat surveys for vegetation and sweep net and pan traps for other macroinvertebrates. The results from Generalized Linear Mixed Models (GLMMs) showed a taxon-specific effect of mowing regime. Bird species richness was significantly suppressed in plots mown with high frequency. Both butterfly abundance and species richness were greatly enhanced by low intensity and low frequency mowing. Odonate abundance, and the abundance and species richness of other macroinvertebrates remained high whenever a portion of vegetation was retained as refuge. Amphibians and reptiles did not prefer to utilize the vegetation grown on grasscretes, and thus showed no impact from different mowing regimes. The overall species richness of vegetation was not affected by mowing regimes, but the domination of tall invasive Brachiaria mutica was suppressed by any mowing activity. To cater for the need of most taxa, we propose a mosaic mowing regime, in which most parts along the channelized river could be mown infrequently to 600 mm tall while some of the patches remain unmown. [ABSTRACT FROM AUTHOR]

Floods are natural disasters that cause serious loss of life and property, especially in highly urbanized regions. Studies based on the numerical modeling and evaluations regarding the legal statute are required to prevent or mitigate adverse effects of flood. This paper focuses on the assessment of flood regulations from the point of stream flood due to insufficient stream section. The entire process was illustrated by using a case study of a stream flood event in Istanbul, Turkey. For this purpose, initially, the hydrologic-hydraulic models of the Eşkinoz Stream Watershed, where the flood occurred on September 8–9, 2009, were created and the flood map was obtained by using Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) and Hydrologic Engineering Center-River Analysis System (HEC-RAS), respectively. The causes of the flood were determined using the maps via the Watershed Modeling System (WMS). In the second part, the public institutions and organizations that have responsibility for the flood damage of the buildings in a private school campus located on the streamside were determined. The current paper presents a comprehensive legislative assessment and an effective approach for flood events in Turkey that may affect both public and private buildings by evaluating the regulations and developing flood models using various methods. [ABSTRACT FROM AUTHOR]

Purpose This study aimed to analyze the bibliographic characteristics and content of articles on flood management published in journals indexed by Scopus written by researchers from throughout the world from 2000 to 2019. Methods We obtained data from the Scopus database on October 2, 2020. “Flood management” was used to search across several categories, including article title, abstract, and keywords, filtered by subject area (social science; environmental science; and business, management, and accounting). We only retrieved articles written in English. We conducted content analysis using the VOSviewer software and visualized the co-occurrence of keywords and bibliographic coupling of sources and countries. Results Following the study protocol, we found 984 articles on flood management over the past 20 years. Among the three subject areas, environmental science was the most productive field for publishing flood management articles. Flood control, flood management, and risk assessment were the top three most popular topics. Flood management publications were published in 266 journals. In total, 86 countries collaborated to produce research related to flood management. Natural Hazard Journal and Journal of Flood Risk Management were the most prominent journals. Institutions from Europe ominated the top 10 institutions with the most publications by affiliated researchers. Conclusion From a global perspective, flood management research in the past two decades has increased significantly. There were five major topic clusters, and European-published journals ominated publications. Thus, Asian institutions need to conduct more active research on this topic.

The study presents problem of floods management for lowland rivers and provides solution for such complex task. The paper aims to elaborate a methodology for flood management model on large lowland rivers using precision digital terrain models (DTM) and combined 1D/2D unsteady flow model. The river Danube on the territory of Serbia was used with its tributaries for the development of the model. The length of the hydraulic model is 715 km and the achieved accuracy of the model, by comparing the calculated and observed levels on 10 water stations, is below 10 cm. Combined 1D/2D HEC-RAS model is adjusted by making use of the resulting high-resolution input. The ability of the combined 1D/2D model, based mainly on the high-accuracy input data, provides an accurate estimate of flood wave propagation. The result of this paper is a defined methodology providing sufficient accuracy to the hydraulic model of flood wave propagation in case of large lowland rivers, requiring acceptable short calculation time. Also, the methodology to specify relevant flood stage (design flood) which is used to determine levee crest elevation is developed in this paper.

Abstract This study assesses the potential downstream impacts in the event of a flood due to failure, either structural or operational, of the Grand Ethiopian renaissance dam (GERD). The following two failure scenarios were modeled as part of this study: Dam Break (DB) and MisGuided Dam Operation (MGDO) as a result of a false flood signature. The DB scenario shows that 40% of the intensively cultivated Gezira Plain would be inundated with average water depths of more than 10 m, resulting in catastrophic loss of highly productive farmlands, livestock, inhabitants, and infrastructure. This scenario did not model damage further downstream since for this magnitude flood it will require another flood routing model given the more complex geometry downstream of the Gezira Plain. In the MGDO scenario flood flows are lower and would have no impact on the Gezira Plain but would reach the High Aswan Dam (HAD) and fill it to its maximum allowable capacity for two and a half months and it would require emergency releases for more than 5 months. The required emergency releases from the HAD are expected to create significant flooding downstream. To accommodate the potential of extra releases from the GERD during flood events the operational rules for the HAD should be modified. However, providing more flood buffer at the HAD will limit the live capacity that is currently used for securing downstream flow requirements during drought periods. One of the expected impacts of increasing the flood buffer would be a reduction of the HAD's contribution to Egypt's GDP. Based on the results of this study the operational rules for the GERD and the HAD should be evaluated and possibly modified.

After centuries of adapting to coastal living, increases in stormwater and tidal flooding events, along with projected sea level rise, led Charleston, South Carolina, USA to define flooding as an existential threat to the city. With billions of planned flood management projects underway, and additional billions of federal disaster flood recovery funds allocated to the State of South Carolina, the Governor's office established a South Carolina Office of Resilience in September 2020, with a focus on water management. The City of Charleston developed its own Flooding and Sea Level Rise Strategy. Simultaneously, the fourth National Climate Assessment pointed to heat health risks and projected costs of lost labor productivity concentrated in the Southeast, yet local recognition of heat as an equivalent threat to flooding was not apparent. Although Charleston's All Hazards Vulnerability Assessment included extreme heat as a significant hazard, without a group focused on heat, ongoing work in the city continued to prioritize water management as annual flood events rapidly escalated. This narrow adaptation framing was further solidified as funding focused on flood recovery and adaptation and technical experts worked within water-related boundaries. These interacting forces led to Hazard Bias, an inherent organizational process of reinforcing focus on a single hazard in the context of compound, complex hazard risks. To adapt to increasing heat, Charleston will need to raise compound risk awareness and adjust its capital investments in resilience to be inclusive of heat mitigation and adaptation as well as water. Yet in 2020 Charleston lacked basic urban heat data, technical expertise, and a strong source of motivation to develop a prioritization approach for recognizing multiple risks and complementary adaptation opportunities in those investments. Recognizing the inherent bias, a new coalition of heat researchers, practitioners, and health experts launched a tripartite heat-health research program and spurred the development of a new heat network in Charleston. The network reduced hazard bias by raising heat-health risk awareness and by intervening in adaptation planning to broaden water-only considerations to be inclusive of water AND heat. This paper provides a detailed case study how the intersections of multiple networks, messengers, and messages contributed to broadening the local resilience agenda from a “hazard bias” and how the lessons learned during this transformative process further reveal health inequities.

Urban agriculture (UA) can be used as a strategy to ensure the building of resilient cities. The objective of this study is to extensively review the literature on what and how UA can contribute to flooding risk management in the effort to build water resilient cities in several ways. UA plays a key role in changing linear water economy to circular thereby cutting the dependence of urban areas on rural for ecosystem service provision including flooding risk management. Urban flood-prone areas can be allocated to UA in pursuit of flood management while at the same time serving as a buffer zone to safeguard environmentally vulnerable areas from the damage of floods. UA exhibits higher infiltration capacity expressed in terms of curve number (CN) and is affected by soil type and management practice. Flooding risk and its management can be shared between government and local institutions to make the system feasible. Rainwater and flood harvesting are important in building a water-resilient city where the Sponge City Concept demonstrated the possibility of reducing 100-year storms to 25-year storms. Urban administrators and planners need to make UA the prior urban land-use type as it enables the building of a water resilient city while responding to multiple policies and objectives than other urban land-use types.

Floodplains in California and elsewhere are productive natural habitats with high levels of biodiversity, yet today they are often permanently disconnected from rivers by urban or agricultural development and flood management structures. This disconnection poses a threat to many native fish, bird and other species that evolved to take advantage of seasonal floodplain inundation. The traditional restoration approach to this problem is to recreate historical floodplain by restoring natural hydrologic and successional processes. However levees, dams, and development have made this largely impossible in much of the developed world. Reconciliation ecology recognizes this limitation, and encourages instead the re-engineering of human dominated landscapes to allow for coexistence of native species and human uses. Flood control bypasses are particularly promising places to reconcile historical fish and bird uses of floodplain habitats with human uses. However, the reconciliation approach requires nuanced management of a complex system. Using the Yolo Basin flood bypass in California’s Central Valley as an example, this study develops formal multi-objective optimization to help planners identify management options that best improve habitat quality for fish and birds with minimal costs to farmers or wetland managers. Models like the one developed here can integrate large amounts of data and knowledge, and offer an explicit accounting of relationships and trade-offs between different objectives. This is especially useful in reconciliation planning, where many uses and variables interact on a landscape, and deliberate re-engineering requires consideration of many decisions simultaneously. Initial results suggest that modest land-use changes and inundation management strategies can significantly improve seasonal bird and fish habitat quality at little cost to farmers or other human land uses. The model applications demonstrate the usefulness of multi-objective optimization in reconciling managed floodplains, and provide a framework for integrating new knowledge and testing varying assumptions to improve management over time.

Climate change is threatening coastal cities affected by multiple hazards worldwide. Due to the increase in extreme weather events and the low capacity of cities to adapt to these odds, losses, exposure, and fatalities arise with the occurred events. Besides, traditional hazard mapping and risk planning techniques often fall behind when facing a climate crisis since extreme changes in quantity, frequency, and distribution of meteorological phenomena are observed. Specific and localized flood vulnerability mitigation strategies need to be developed, particularly for settlements on coastal and sloppy areas with a high risk of stream accumulation during rainfall days. This paper uses the urban flood risk mitigation of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) generated within the Natural Capital Project to determine İzmir's cloudburst vulnerability level. The city has experienced several cloudbursts in the last couple of months which inundated densely populated areas. The soil's hydrologic conductibility and the land use/land cover (LULC) map were required as main inputs. The LULC map was produced on the basis of surface imperviousness. The model calculates the run-off volume and how much is retained by soil and vegetation. Outputs were used to concretely apply the sponge district concept while designing performance-based ecosystem solutions. In the light of the findings, the new performance-based design demonstrated how digital ecosystem modelling could support the urban design decision-making process. [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]

The hydrometeorological data was analysed for the identification of the causality and behaviour of the 2010 flood in Lithuania. Moreover, 326 different articles about the selected flood were collected and reviewed to establish the extent of damage and losses. The multi-criteria analysis was used for the assessment of socio-economic risk in the area of 1% probability inundation. The applied ranking approach of the socio-economic risk was compared with the ratio-based risk of Flood Hazard and Flood Risk Maps (FHRM). The results of this paper indicated that the flood was caused by ice jams and was crucial for the areas of higher risk. The magnitude of the 2010 flood revealed many issues related to flood management. The total economic losses reached 2.8 million EUR. The effects of the flood significantly impacted socio-economic conditions and the environment of residents within the areas of inundation. The assessment of socio-economic risks indicated additional sensitive areas, which were not sufficiently taken into account in FHRM. The analysis highlighted the current issues in flood management and the consequences of not taking appropriate flood management measures. [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]

This paper explores the river landscapes and concomitant values resulting from tensions between flood management and visions of a River City. The aim is to contribute to an understanding of the management of urban waters as valuation practices. We regard valuation practices as co-constitutive of current and future river landscapes. Sweden's second-largest city, Gothenburg, is located next to the sea, and the Göta River, Sweden's largest water system, runs through it. Our empirical focus is on how this city approaches increasing risks of flooding. We explore three approaches that have been formulated in relation to flood management: defend, retreat and attack. We ask how these approaches are applied in the management of Göta River flooding and in the city's vision of a future Gothenburg that embraces the river as a genuinely positive aspect of urban life. We present the case as a journey that takes us upstream from the river's sea inlet port and through Gothenburg. During our kilometre by kilometre journey, the river's appearance shifts. The varied river landscape mirrors the diversity in how its waters are valuated, both historically and in present times. The perception of urban waters is shaped by practices of valuation. These valuations are generative. They connect the value of water to other entities, actors, plans, activities and buildings, and they are thus key to the river landscapes that will eventually be realised. By way of conclusion, we identify a number of governance challenges that are particularly relevant to urban rivers. [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]

Floods can be identified as one of the devastating natural phenomena, which resulted in a considerable amount of social, economic and environmental impacts. Sri Lanka is a country that is highly vulnerable to floods due to its unique geographical location and topography. Many flood management measures, which mainly include structural and non-structural have implemented to reduce the impact of floods. Among them, structural measures play a vital role in flood management. However, the failures in achieving the expected performance of these existing structural measures urge the need to identify issues with them and overcome those issues to enhance the flood management process in Sri Lanka. Hence, this study focused to investigate the issues related to structural flood management measures in Sri Lanka to bridge this knowledge gap. Initially, a literature review was conducted to gain a theoretical understanding of the research area. The research approach was qualitative, which was followed by two in-depth case studies. Semi-structured interviews were conducted with 10 industry experts to gather data. Collected data were analysed via content analysis. Empirical research findings revealed that structural measures play a prominent role in flood management. However, significant issues such as ageing of structural measures, leakages, construction faults, inadequate capacity, blocking of water flow and possibility of collapsing were identified in these existing structural flood management measures, which negatively impact the effectiveness of the overall flood management process within the country. The findings of this study will lead to gain a proper understanding of gaps and weaknesses in structural flood management measures in Sri Lanka and would influence the policymakers and other respective practitioners in disaster management to enhance structural flood management by using their novel ideas and concepts. [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]

Operational extended range forecasts are being disseminated once every week by the India Meteorological Department (IMD) for several sectorial applications. These forecasts show a reduction in amplitude and variance as a function of lead-time. Such reductions in variance can be due to several physical factors: inherent forecast model bias, a problem relating to initial conditions, leaddependent statistical biases, etc. A week-by-week analysis shows that such biases are not systematic. Rainfall forecasts are underestimated in some regions, while others overestimate rainfall amplitude. To correct the bias in the extended range weekly averaged forecast, a statistical post-processing method (normal ratio correction) is proposed to make the outlook more valuable at a longer lead-time. The correction method is based on the World Meteorological Organization (WMO) technical guidance on rainfall estimation and is also shown to be useful for rainfall forecasts. In this analysis, we evaluate the extended range forecast skill at the river sub-basin-scale and show that there are several river sub-basins over the central Indian region where the correction has improved the model forecast in the one to two-week range. Although this analysis was tailored toward making the river basins and sub-basins of India more readily realizable for flood forecasters, it can be used for any administrative boundaries such as block, district, or state-level requirements. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the feasibility offlood management based onthe concept of Integrated Watershed Management (IWM) via a literature review and field surveys. The investigationfocused on the primary industry of oil palm plantations in Malaysia. Although the country is promoting the palm oil industry, the impact of oil palm plantations on the local environment has been relatively disregarded because of the benefits and opportunities, such as subsidies, jobs, and amenities,which the local companies/people can obtain. Effective flood management inoil palm plantations entails the local peoples’ understanding and participation in the management activities, such as removing fallen leaves and weeding an area. Theflood management strategiessuggested inthis research provide new insights into local flood management, which usually focuses on the hydrologic aspects, by promoting the integration of the actual-local environment and local people’s actions for their environment within the framework of IWM.

Floods are a natural phenomenon that causes heavy losses of life and property and ‎human societies every year and people have accepted it as an inevitable event. In this research, to predict the flooding in Sardabrood basin ‎ SWAT hydrological model was used. Information needed for this research, ‎including topographic maps, land use, soil data, and meteorological data, data about daily ‎rainfall, temperature, and flow rate were prepared beforehand. SUFI2 program was used for model ‎calibration. After the calibration and optimization of the model, validation of the model in the ‎study area was done. The calibration of the model wad performed for the years 2003 to 2009 and validation was performed for ‎the years 2010 to 2013. To analyze the results of statistical indicators R2, bR2, and Nash Sutcliffe ‎coefficient were used. After model calibration the respective coefficients were, 0.77, 0.63, and 0.77 and ‎the respective validation coefficients were 0.79, 0.76, and 0.71. The sensitivity results of 31 parameters that are influential on runoff water showed that fixed parameters of groundwater base flow, its time, and the minimum amount of water necessary for groundwater base flow are more sensitive than other parameters. Number Sardabrood parameter curves were used for flood basin. Sardabrood basin was divided into 24 areas to study the flooding pattern. Finally using the above mentioned models it was concluded that sub basin No. (6) had the first-rank with runoff 123.05, ‎‎sub basin No. (10) had the second rank with runoff in terms of flooding and sub basin No. 1 with a 12.33 has the least amount of runoff.‎

This work introduces an unprecedented flash flood that resulted in nine casualties in Shimen Valley, China, 2015. Through field survey and numerical simulation the causes of the disaster are systematically analyzed, finding that the intense storm, terrain features, and the large woody debris (LWD) played important roles. The intense storm induced fast runoff and, in turn, high discharges as a result of the steep catchment surfaces and channels. The flood flushed LWD and boulders downstream until blockage occurred in a contraction section, forming a debris lake. When the debris dam broke, a dam break wave rapidly propagated to the valley mouth, washing people away. After considering the disaster-inducing factors, measures for preventing similar floods are proposed. The analysis presented herein should help others manage flash floods in mountain areas.

Abstract 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.

An aspect correlated with climate change is certainly represented by the alternation of severe floods and relevant drought periods. Moreover, there is evidence that changes in climate and land cover are inducing changes in stream channel cross-sections, altering local channel capacity. A direct consequence of a significant change in the local channel capacity is that the relationship between the amount of water flowing at a given point in a river or stream (usually at gauging stations) and the corresponding stage in that section, known as a stage–discharge relationship or rating curve, is changed. The key messages deriving from the present work are: (a) the more frequent and extreme the floods become, the more rapid the changes in the stream channel cross-section become, (b) from an operational point of view, the collection and processing of field measurements of the stage and corresponding discharge at a given section in order to quickly and frequently update the rating curve becomes a priority. It is, therefore, necessary to define a control system for acquiring hydrological data capable of keeping river levels and discharges under control to support flood early warnings and water management. The proposed stage–discharge management system is used by the Civil Protection Service of the Marche Region (east-central Italy) for the monitoring of river runoff in the regional watersheds. The Civil Protection Service staff performs stage–discharge field measurements using water level sensors and recorders (e.g., staff gauges, submersible pressure transducers, ultrasound and radar sensors) and a current meter, acoustic doppler velocimeter, acoustic doppler current profilers, portable mobile radar profiler and salt dilution method equipment, respectively. Power functions are fitted to the stage–discharge field data. Furthermore, extrapolation is performed to cover the full range of flow measurements; in general, extrapolation is not an easy task because of sharp changes in the stream cross-section geometry for very high or very low stages. In the present work, we also focused attention on the application problems that occur in practice and the need for frequent updating.

Operation of gated spillways during flood is a complex issue in dams. Therefore, availability of a comprehensive operational rule can help operation effectively. Several methods were performed to plan reservoir management rules in flood. Among the proposed models, simulation-based models are usually more flexible and easier to understand. Various techniques, such as VEM (Volumetric Evaluate Method) and K-Method, have been applied for simulation of a reservoir in flood. The output of these methods is discharge flow. Operation management of flood with discharge pattern is very complicate. In such a situation, having a comprehensive operational rule is vital to help the operator to manage more effective action. In this regard, this paper focus on the above objective. For this purpose, a novel method of Intelligent Reservoir Flood Operation Management (IRFOM) has been introduced in the present study. The output of the method is gates opening which is easy to use in operation management. Karkheh and Dez dams with the actual operation data in flood, and Kanisib Dam under construction, as case studies, were simulated by the method, and the results were compared to the results of VEM and K-Method methods and the recorded data. The present study shows that the IRFOM method reduces maximum discharge flow effectively, in comparison with VEM and K-Method results, due to full use of the reservoir capacity and output discharge distribution over a more extended period. [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]

The number of river floods has increased worldwide, as well as in Nakorn Ratchasima Province in Thailand. To prevent disasters, the Royal Irrigation Department (RID) constructed thirteen regulating structures to control discharges. Currently, the local controllers spatially control these structures to minimize the subsystem's damage, regardless of the effects on the overall system performance. In this study, the concept of combining real-time flood management tools and the cascade Model Predictive Control (MPC) as well as application of GIS has been proposed and verified with the 2013 flood event. The distributed control of the existing hydraulic structures on the large scale of the Lamtakong River made optimal use of the retention basin storage capacity with the considerations of both local performance and global system interactions. The model proposes an optimal gate opening of each cascade at the specified time, from the beginning until the end of flood hydrographs. The results of the controlled water level indicate the efficiency of the CMPC, which is more satisfied satisfactory than the PID and practice technique of RID, as evidenced by the water level of 0.5 m that is lower than the level of the riverbank at Nakhon Ratchasima City. A comparison of flood areas between the historical flood in year 2013 and Management by CASCADE MPC shows by GIS flood map that in the case of Management by CASCADE MPC, it can reduce the flood area in Nakhorn Ratchasima city by almost 60%. [ABSTRACT FROM AUTHOR]

Wetlands in urban ecosystems provide significant environmental benefits. In the present study, the concept of urban constructed wetland development is studied from the viewpoint of urban planning with dynamic water level orifice setting controller. A two-step modelling procedure is carried out: (1) development of a hybrid model, by coupling a well-established two-dimensional hydrodynamic model (International River Interface Cooperative, iRIC) with a one-dimensional physically-based, distributed-parameter model (Storm Water Management Model, SWMM), to compute and map flood scenarios and to identify the flood-prone areas; and (2) use of SWMM to simulate the water inflow to the proposed constructed wetland, which acts as a cushion for storing excess flood water. The proposed methodology is implemented on the Jahangirpuri drain catchment located in Delhi, India. Results show that the hybrid model is effective, and the simulations are observed to be in good agreement with the recorded data, which assist in detecting the flood-prone areas. Further, an estimation of the impact of the proposed constructed wetland on catchment hydrology indicates an overall reduction of 23% in flooding adjacent to the channel with a significant reduction in backflow as well as water depth in the drain. The flapgate at the outlet of the wetland helps in maintaining the desired water depth in the wetland. The outcomes of this study will assist the hydrologists and administrators in urban stormwater management and planning to mitigate the impact of floods in urban watersheds. [ABSTRACT FROM AUTHOR]

Grasslands vary with diverse forms and functions ranging from monocultures of perennial rye grass to more biodiverse unimproved grasslands which cover around 5% of Europe. Despite the broad diversity of grassland types, within environmental and flood risk models grasslands are frequently represented by a singular set of hydrological and structural parameters which belies their diversity and complexity. This study aimed to determine empirically the extent to which improved versus unimproved grasslands exhibit different hydrological connectivity. Working in SW England at neighbouring field sites with comparable slopes and rainfall regimes, we used unpiloted aerial vehicles to survey a tussocky Molinia caerulea dominated unimproved grassland field (MCUG) field and a Lolium perenne dominated improved grassland (LPIG) field. Using digital photogrammetry workflows applied to the overlapping aerial images, we produced a digital surface model (DSM) at 0.03‐m resolution from which flow pathways were modelled using GIS and compared with 1‐m LiDAR and DSM produced by a global navigation satellite system (GNSS). MCUG had longer, tortuous pathways through the dense tussock network with a drainage density of 2.54 m m−2. This was significantly greater than drainage density in the LPIG (1.82 m m−2). As a result of this study, we rescaled the Manning's n value for MCUG according to photogrammetrically‐derived roughness values. We suggest it should lie between 0.075 and 0.09. Our data shows that MCUG can play an important role in reducing overland flow impacts when compared to LPIG through lower connectivity which can delay run‐off to rivers. [ABSTRACT FROM AUTHOR]

Intersectoral collaborations are an integral component of the prevention and control of diseases in a complex health system. On the one hand, One Health (OH) is promoting the establishment of intersectoral collaborations for prevention at the human-animal-environment interface. On the other hand, operationalising OH can only be realized through intersectoral collaborations.This work contributes to broadening the knowledge of the process for operationalising OH by analysing the governance structures behind different initiatives that tackle health problems at the human-animal-environment interface. The cases taken as examples for the analysis are the control and response to rabies and avian influenza under “classical OH”, and the management of floods and droughts for insights into “extended OH”. Data from Ghana and India were collected and compared to identify the key elements that enable ISC for OH.Despite the case studies being heterogeneous in terms of their geographic, economic, social, cultural, and historical contexts, strong similarities were identified on how intersectoral collaborations in OH were initiated, managed, and taken to scale.The actions documented for rabies prevention and control were historically based on one sector being the leader and implementer of activities, while avian influenza management relied more on intersectoral collaborations with clearly defined sectoral responsibilities. The management of the impact of flood and droughts on health provided a good example of intersectoral collaborations achieved by sectoral integration; however, the human health component was only involved in the response stage in the case of Ghana, while for India, there were broader schemes of intersectoral collaborations for prevention, adaptation, and response concerning climate change and disaster.