Flood Protection Research Articles

Considerations for the use of laboratory-based and field-based estimates of environmental tolerance in water management decisions for an endangered salmonid

Water infrastructure development and operation can provide for human economic activity, health, and safety. However, this infrastructure can also impact native fish populations resulting in regulatory protections that can, in turn, alter operations. Conflict over water allocation for ecological function and human use has come to the forefront at Shasta Reservoir, the largest water storage facility in California, USA. Shasta Reservoir supports irrigation for a multibillion-dollar agricultural industry, provides water for urban and domestic use, provides flood protection for downstream communities, and power generation as part of the larger Central Valley Project in California. Additionally, an endangered run of Chinook Salmon relies on cold water management at the dam for successful spawning and egg incubation. Tradeoffs between these uses can be explored through application of models that assess biological outcomes associated with flow and temperature management scenarios. However, the utility of models for predicting outcomes of management decisions is contingent on the data used to construct them, and data collected to evaluate their predictions. We evaluated laboratory and field data currently available to parameterize temperature-egg survival models for winter run Chinook Salmon that are used to inform Shasta Dam operations. Models based on both laboratory and field data types had poor predictive performance which appears to limit their value for management decisions. The sources of uncertainty that led to poor performance were different for each data type (field or laboratory) but were rooted in the fact that neither data set was collected with the intention to be used in a predictive model. Our findings suggest that if a predictive model is desired to evaluate operational tradeoffs, data should be collected for the specific variables and life stages desired, over an appropriate range of values, and at sufficient frequency to achieve the needed level of precision to address the modeling objective.

Harnessing nature-based solutions for economic recovery: A systematic review

Nature-based solutions (NbS) involve working with nature to address societal challenges in ways that benefit communities and biodiversity locally. However, their role supporting economic recovery from crises, such as those arising from conflicts or pandemics remains underexplored. To address this knowledge gap, we conducted a systematic review of 66 reviews on the economic impact of nature-based interventions. Most demonstrated positive outcomes for income and employment, though those with critical appraisal of underlying studies reported more mixed outcomes. These varied results were influenced by factors such as the balance between short-term and long-term gains, market conditions, regional effects, reliance on subsidies, and discrepancies between expected and actual economic benefits. National-scale economic growth assessments were scarce. Half of the cases featured nature-based food production investments, with much evidence from sub-Saharan Africa, East Asia and the Pacific. The few reviews comparing NbS with alternatives found that NbS delivered equal or better economic outcomes. NbS also provided broader benefits like food and water security, flood protection and community empowerment. We identified key factors influencing the delivery of benefits and trade-offs, finding that NbS must adhere to best practice standards, with community involvement being critical for equitable outcomes. Well-designed NbS can create diverse job opportunities at different skill levels, diversify income, and improve resilience, offering a rapid, flexible response to economic shocks that can be targeted at deprived communities. By integrating traditional, local and scientific knowledge, NbS can enable eco-innovation, and drive the transition to a clean and efficient circular economy, with high economic multipliers spreading benefits throughout economies. The evidence underscores the need to incorporate NbS in investment programs to concurrently address economic, environmental, and societal challenges. However, improved monitoring of economic, social and ecological outcomes and the development of comprehensive accounting systems are needed to better track public and private investments in NbS.

An Analysis of Policy Frameworks on Business Formulization and Disaster Management to Mitigate Flood Loss and Damage Among Informal Businesses in Sri Lanka

The 27th Conference of the Parties to the United Nations Framework Convention on Climate Change in Egypt made a historical decision on disaster loss and damage for vulnerable countries. Even though parties agreed to salvage vulnerable nations with generous support, a fundamental question remains as to the extent to which these vulnerable countries can accurately identify the most vulnerable communities/areas. In Sri Lanka, informal businesses are particularly vulnerable to floods, but their informal status has limited the extent to which they could receive flood protection, including disaster-resilient infrastructure developments. The main objective of this paper, therefore, is to identify challenges that informal businesses have experienced in dealing with flood disaster risks. In doing so, we analyzed government policies and laws that are related to business formalization and disaster management. We also conducted interviews with key informants to verify our data. Our analysis found that the Sri Lankan government requires informal business owners to follow complicated rules to register their businesses. For these owners, who are not highly educated, these processes and fear of high tax rates discouraged registering their businesses. The central government tends to prioritize flood mitigation actions for formalized business areas. Informal businesses are not usually covered by flood insurance and compensation. In conclusion, we emphasize the need to establish widely available legal and administrative support for informal businesses to register. Adopting business continuity plans (BCPs) and keeping standardized business records also help businesses minimize flood loss and damage.

NATECH POTENTIAL DUE TO EMERGING CLIMATE HAZARDS AND AWARENESS OF THE LOCAL STAKEHOLDERS IN THE COASTAL INDUSTRIAL SITE OF KUALA SELANGOR, MALAYSIA

Climate change may put more industrial sites at risk of Natech incidents, particularly in coastal areas due to the compounding effects of climate hazards. This study investigates industrial facilities with potential for Natech due to emerging floods and delineates awareness of the exposed stakeholders, using the best available information, to strengthen local level climate change adaptation and disaster resilience in IKS Kuala Selangor, Malaysia. Two major methods were employed, conceptual site modelling using the source-pathway-receptor-consequence approach and semi-structured interviews to get insights from the local stakeholders. Findings reveal that in the worst-case scenario, manufacturing industries are exposed to floods, have limited flood protection and unknown containment and storage measures of hazardous materials within their facilities. While the high concentration of total metals in the surrounding topsoil has not been linked directly to the manufacturing industries, they have potential for Natech in future flood events. An area with environmentally available lead and arsenic accumulation linked to agricultural activities is also a potential point source for pollution during flood events in the worst-case scenario. Although most of the exposed local stakeholders are aware of climate hazards, they are not prepared for the risks of Natech. The local adaptation plan should include awareness building on Natech targeting the exposed local stakeholders as well as adequate flood protection and updated guidance on managing the safety of hazardous materials at manufacturing industry facilities.

Analisis Tingkat Kerawanan Banjir di Sub Daerah Aliran Sungai (DAS) Kampar Kiri di Kecamatan Kampar Kiri

This study aims to describe and analyze the flood vulnerability level in the Kampar Kiri Sub-Watershed, Kampar Kiri District, as well as the extent of flood-prone areas impacting settlements in the region. The primary focus of this research is to understand the flood risk of the area and its effects on the existing settlements. The method applied in this study is Multi-Criteria Evaluation (MCE) using a Geographic Information System (GIS) approach. MCE is used to determine the weights of parameters affecting flood vulnerability and to select appropriate methods for analysis. This approach has proven effective and efficient in flood risk analysis, as demonstrated in previous studies. The parameters analyzed include slope, elevation, rainfall, soil type, land use, and distance from rivers, which are calculated using scoring methods and overlaid to produce a flood vulnerability map. The results indicate that the flood vulnerability level in the Kampar Kiri Sub-Watershed is categorized into three classes: not vulnerable, vulnerable, and highly vulnerable. The areas for each class are: not vulnerable with 16,854 hectares, vulnerable with 58,543 hectares, and highly vulnerable with 11,506 hectares. The extent of settlements in the vulnerability zones includes: vulnerable zone with an area of 277 hectares (approximately 20.83%), and highly vulnerable zone with an area of 1,054 hectares (approximately 79.17%). Based on these findings, it is recommended that the Kampar Kiri District government enhance land use planning to reduce flood risks, collaborate with the Kampar Public Works and Spatial Planning Office, and improve infrastructure such as drainage channels and flood protection embankments.

Comparison of UAV Orthophoto and Ground Survey at a Flood Protection Embankment

In the study, I compare the elevation data of points obtained from an orthophoto taken from a drone with the heights of points measured from the area by ground survey procedure and measuring station. I examine the usability of the points determined from the orthophoto for flood protection and for assessing flood protection embankments. I present the difficulties of assessing floodplains. The taking of orthophotographs and the data obtained from them may be important in determining the conditions after the floods have subsided and in detecting sediment deposition. My aim is to examine to what extent orthophotographs can be used to determine embankment heights in case of flooding, in order to avoid water overtopping of protective embankments.

Factors influencing farmers' willingness to provide private land for a coordinated flood mitigation scheme in the Drin basin

AbstractFlooding poses a significant and recurring threat in numerous regions. The adverse impacts of flooding can be mitigated through risk sharing, such as insurance or risk reduction. However, insurance might not be accessible in underdeveloped markets or in instances where floods are too frequent. Similarly, the necessary funding or land for structural measures might not be available. Alternatively, measures could be implemented on private land, either through individual initiatives or as part of a coordinated effort. This approach was explored in the flood‐prone regions of Albania and North Macedonia. A survey conducted among 124 farmers revealed that 73% of them are willing to allocate land for flood mitigation, provided they receive adequate compensation. Furthermore, certain factors increase farmers' willingness to cooperate. A logit model indicated a positive correlation between expectations of future floods (increased severity and frequency), receipt of ex‐ante financial support, positive perception of the effectiveness of agricultural flood mitigation measures, and age. Those who view flood protection as personal responsibility and those more inclined to pay for flood insurance are less likely to cooperate. The findings could be utilized to identify farmers who are likely to contribute to establishing a coordinated effort on a stable basis.

Chiefs and floods: hybrid governance and co-production of flood risk adaptation in Tamale, Ghana1

ABSTRACT Climate change is changing physical and social risks facing people in African cities. Emerging awareness is beginning to stimulate a wide range of adaptive responses. These responses are playing out in a complex institutional and governance context which shape their effectiveness and legitimacy. Employing a hybrid governance approach, we investigate the development of flooding and flood protection in the context of urban development in Tamale, Ghana. We argue that the interplay between traditional and state-based authority shapes the market for land, the regulation of land use and the provision of urban services, including flood protection. Hybrid governance influences the types of knowledge applied to urban problem-solving, the legitimacy of choices made, the human and other resources that can be deployed in building community resilience and the willingness to act in the provision of public goods by communities. We suggest how the existing hybrid governance setting could be strengthened to achieve more effective and legitimate adaptation to dynamic flood risks under climate change in Tamale, with lessons for other West African contexts.

The Flood Protection Issues in the National Crisis Management Plan 2021/2022

The Flood Protection Issues in the National Crisis Management Plan 2021/2022

Green spaces and flood vulnerability in urbanising regions: a case study in the Philadelphia metropolitan area

ABSTRACT Flooding continues to be one of the most significant natural hazards, disproportionately impacting vulnerable populations in urbanising regions. This study aims to examine the relationship between green space density and flood vulnerability in the Philadelphia Metropolitan Area by integrating social and geophysical data. The research focuses on identifying areas where high flood vulnerability coincides with low green space availability, as these are critical regions for targeted intervention. Using social vulnerability indicators such as income, age, and housing characteristics, combined with geophysical factors like soil permeability and drainage density, the study assesses flood vulnerability across census block groups. Local Indicators of Spatial Association (LISA) and discriminant analysis were employed to detect spatial clusters with elevated flood risks and low green space density. Results reveal that these high-risk clusters are concentrated in densely urbanised areas such as Norristown, where lower-income and elderly populations are overrepresented. These findings reinforce broader environmental justice concerns, as socially vulnerable communities face compounded risks from both inadequate flood protection and limited access to green spaces. The study emphasises the need for integrated flood management, combining green infrastructure with structural interventions, to guide urban planners and policymakers in reducing flood risks and promoting environmental equity.

Research on Internal Flooding Analysis of Small Modular Reactors Based on Particle Method

Abstract The analysis of internal water flooding in nuclear power plants is a necessary part of safety review in the approval process of nuclear power plant construction projects. According to relevant regulations, it is necessary to conduct water flooding spread analysis on pipelines, water tanks, or pools filled with liquid in nuclear power plant buildings, analyze the spread path and water flooding height. This article analyzes and calculates the flow characteristics of water in a nuclear power plant building using a fluid calculation method based on the Lagrangian method (particle method). Taking the small modular reactor JR building as a case study, it analyzes the spread and height of four water flooding sources inside the building. According to the simulation time of 1800S, the results show that the flooding caused by the No. 2 water source is the most severe, with a flooding height of 1.367m. Drainage or preventive measures need to be taken to prevent the pipeline from breaking accidents; The flooding sources 1, 2, and 4 have a relatively mild impact, resulting in a lower flooding height and will not have a significant impact on important safety equipment, with little impact on the safety of nuclear power plants. The CFD analysis method was used to conduct water flooding analysis for nuclear power plants, which has the characteristics of strong adaptability and good visualization. It can dynamically simulate the entire process of water flooding analysis and better guide the design of water flooding protection for nuclear power plants.

Channel restoration in urbanized systems: Guiding design using ecological flow targets and future management scenarios

AbstractRestoration of urban rivers must simultaneously design for ecological habitat while accounting for altered flow regimes associated with urban runoff, flood protection, and industrial/wastewater discharge. The goal of this study was to use ecological flow targets to guide channel restoration of the Los Angeles (LA) River across potential future flow regimes. Using a one‐dimensional hydraulic model, we simulated a range of channel cross section configurations subject to different flow management decisions (wastewater reuse, low‐flow [LF] treatment, and baseflow augmentation). Hydraulic results were assessed relative to ecohydraulic targets for desirable aquatic species in the LA River (willow, steelhead trout, and Santa Ana sucker). Results suggest that, along the mainstem of the LA River, restoration designs that include narrow LF channels may support Santa Ana sucker habitat and steelhead migration if management decisions decrease instream flows (e.g., by reusing treated wastewater). However, the same channel design and management decisions may not provide conditions needed to propagate floodplain vegetation such as willows. In tributary reaches, flows are too low to support habitat conditions for Santa Ana sucker or steelhead but may be able to support riparian habitat if a soft‐bottom LF channel and active floodplain are present. In general, results illustrate the trade‐offs between water management goals and habitat requirements for target species.

Using ARIMA and ETS models for forecasting water level changes for sustainable environmental management

It is vital to provide useful hydrological forecasts for urban and agricultural water management, hydropower generation, flood protection and management, drought mitigation and alleviation, and river basin planning and management, among other things. This paper introduces a simple and flexible hydrological time series forecasting framework. Predicting water levels is crucial, given the need for sustainable environmental management. The prognosis should be reasonable to persuade individuals to take proper precautions. While many methods have been developed to predict water levels, here the effectiveness of two approaches to predicting river water levels was assessed. For this purpose, nine years of data were used, which were divided into input data (2014–2021) and validation data (2022), on water levels in the Morava e Binçës river for the Vitia station, in the form of monthly time series records, to identify the best model among those used and to identify the information necessary for water resource management and hazard control. Models Autoregressive Integrated Moving Average(ARIMA) and Error Trend and Seasonality, or Exponential Smoothing (ETS), were examined using the R package to determine the most accurate. The results indicate the applicability of both models, as evidenced by the Root Mean Square Error (RMSE) and the Mean Absolute Error (MAE). The predictive analysis based on historical water levels allowed the identification of distinct periods characterized by high and low water levels between 2022 and 2024, which is important for the area in question due to the numerous flood events occurring here.

Dredged Canals, Wetland Loss, and Legacy

AbstractThe direct effects of converting coastal wetlands to open water by dredging them can be magnified by indirect effects. For example, dredged canals allow for recovery of mineral fluids 1000 s of m belowground which may induce geological subsidence or faulting; the dredged material deposited at the surface creates levees that redirect overland water flows. These indirect factors may stress wetland plants enough so that additional wetland habitat is converted to open water as a result of longer intervals of wetland soil waterlogging and drying, sulfide toxicity, less organic matter and sediment accumulation, and greater erosion. We quantified the indirect effects by demonstrating a robust dose–response relationship between coastal land loss and canal density in the Mississippi and Niger river deltas over 5 decades. Importantly, the ratio of land loss to canal area increases with time—a legacy effect. Surface impediments to water movements rather than belowground subsidence are the dominant causal factor. We also found that flood protection levees on the main river channel did not significantly magnify the effect of dredging on wetland loss. The cumulative effect of these direct and indirect consequences in coastal Louisiana is enormous and continuing, equaling many tens of billions dollars annually. Understanding these effects supports the rejection of a hypothesis that regional river channel flood protection levees or fluid withdrawal is of greater importance than the local changes in wetland hydrology. Wetland restoration/mitigation of dredging impacts on these two coasts can be implemented at a relatively low cost and quickly if this paradigm of the causes of coastal wetland losses is adopted.

Adaptive Operating Rules for Flood Control of a Multi-Purpose Reservoir

Almost all multipurpose reservoirs in Romania were put into operation 30–50 years ago or even earlier. Meanwhile, a large volume of hydrologic data has been collected, and the initial design flood should be reconsidered. Consequently, the operating rules of flow control structures (bottom gates and weir gates) should be re-examined, mainly for medium and low-frequency floods. The design flood is not unique, being characterized by different shapes and time to peak, which has consequences for flood mitigation rules. Identifying the critical design flood is an important preliminary step, although it is usually neglected in flood management. Simulating the operation of the Stânca–Costești reservoir on the Prut River, it was found that the design flood corresponding to the maximum value of the compactness coefficient is the most difficult to mitigate considering the specific conditions of the dam and the reservoir: the prescribed conservation level in the reservoir, and the design flood volume of medium and rare floods that far exceeds the flood control volume. These conditions can jeopardize both dam safety and downstream flood protection. The main steps of the proposed approach are as follows: (1) developing the hydraulic model; (2) statistical processing of the registered floods and defining critical design floods for different AEPs (Annual Exceedance Probabilities); (3) deriving optimal operation rules based on a simulation-optimization model; (4) implementing real-time adaptive operation of the mechanical outlets; and (5) critically assessing the operating rules after the event. Based on the hydrological forecast, if necessary, new outlets are put into operation while keeping the ones already activated. Based on the hydrological forecast and properly operated, the safety of the Stânca–Costești dam is guaranteed even in the event of a 0.1% CC (Climate Change) flood. However, for floods greater than 1% magnitude, the carrying capacity of the downstream riverbed is exceeded. The main gaps addressed in this paper are the following: (1) the establishment of critical design floods, and (2) the adaptive operating rules of outlet devices aimed at optimizing flood control results, using short-term flood forecasts.

ANALISIS HUJAN MAKSIMUM PADA DAERAH ALIRAN SUNGAI BABAK KABUPATEN LOMBOK BARAT

Hydrological analysis is the most important measurement in determining runoff in order to find ways to overcome flooding. The flow rate that is the basis for calculating flood control and protection is the planned flood flow rate obtained from the sum of the volume of rain runoff and the flow rate of the water catchment area in question during a certain return period. This research is a case study using rainfall data for 10 years, namely 2014-2023. Rainfall prediction is an estimate of the amount of rain that will fall in a river basin. There are several methods for determining annual rainfall, the Gumbel distribution method, Pearson log type III, and the normal method. After analyzing the annual rainfall data obtained at the West Lombok Regency Meteorology, Climatology and Geophysics Agency office, using three methods, namely the EJ Gumbel method, the Log Person Type III method and the Normal method, where from the three methods the maximum rainfall difference was quite large, In the following table you can see the difference in the amount of maximum rainfall in the return period T years.

Managing stakeholders for implementing innovations: The case of a flood protection project in Kenya

Innovative projects, such as those for flood protection in developing countries, are urgent, stakeholder intense, and need to be carried out even in contexts where sufficient governance frameworks are not in place. This research seeks to understand how innovative projects can be implemented in weak institutional contexts by focusing on managing stakeholders in the single in-depth case study of the implementation of the SLAMDAM innovative project in the Isiolo County in Kenya. Following the analysis of 12 semi-structured interviews with 27 different stakeholders and 7 observations of stakeholder interactions, we answer the following questions: 1) what are the challenges during implementation of the innovation projects in weak-institutional contexts? 2) how are these challenges addressed through strategies? 3) how can we theorize the relationship between challenges and strategies in weak institutional contexts? The challenges include community resistance, information fragmentation, disjoined efforts, and governance inefficiency. Theoretically, we highlight how ad-hoc workarounds are operationalized in weak-institutional contexts and how they can lead to lasting changes by building governance frameworks in the long term. Practically, this research offer valuable guidance for practitioners involved in innovative projects, particularly in developing countries with weak institutional frameworks.

Designing Post-Fire Flood Protection Techniques for a Real Event in Central Greece

Designing Post-Fire Flood Protection Techniques for a Real Event in Central Greece

Global estimates of 100-year return values of daily precipitation from ensemble weather prediction data

Abstract. High-impact river floods are often caused by very extreme precipitation events with return periods of several decades or centuries, and the design of flood protection measures thus relies on reliable estimates of the corresponding return values. However, calculating such return values from observations is associated with large statistical uncertainties due to the limited length of observational time series, uneven spatial distributions of rain gauges and trends associated with anthropogenic climate change. Here, 100-year return values of daily precipitation are estimated on a global grid based on a large data set of model-generated precipitation events from ensemble weather prediction. In this way, the statistical uncertainties in the return values can be substantially reduced compared to observational estimates due to the substantially longer time series. In spite of a general agreement in spatial patterns, the model-generated data set leads to systematically higher return values than the observations in many regions, with statistically significant differences, for instance, over the Amazon, western Africa, the Arabian Peninsula and India. This might be linked to an overestimation of tropical extreme precipitation in the model or an underestimation of extreme precipitation events in observations, which, if true, would have important consequences for practical water management.

“We live here because of nature”: transformation towards better flood resilience on small Danish islands

Climate change is increasing the threat of flooding on small Danish islands. This article presents the results of a qualitative case study of flood risk perceptions and adaptive actions on three small Danish islands. The study explores how an empirical study of the islanders’ sense of place can contribute to a transformation towards better flood resilience. It finds that sense of place is closely connected to living close to nature, but also it highlights that the meaning given to ‘nature’ varies among the islanders. For some, nature is an uncultivated, wild landscape; for others, it is the present, cultural landscape. Another difference concerns whether the islands are described as a place to make a living or as a place to get away from everyday life. For some, farming and grazing are central to how they make a living on the islands; for others, these activities belong to the past. This insight into differences in the islanders’ sense of place contributes to understanding different perspectives regarding what is worth protecting, and what it is possible to protect from flooding, as well as why it is difficult for the islanders to reach agreement on the subject. This understanding has transformative potential, as it can give the islanders themselves, as well as authorities responsible for flood protection, a valuable insight into what drives and hinders actions to manage or reduce flood risk on small islands.