Community Flood Research Articles

Analysis of Flood Evacuation Process in Vulnerable Community with Mutual Aid Mechanism: An Agent-Based Simulation Framework

Timely and secure evacuation of residents during flood disasters or other emergency events is an important issue in urban community flood risk management, especially in vulnerable communities. An agent-based modeling framework was proposed in order to indicate how the community properties (e.g., community density and percentage of vulnerable residents), residents’ psychological attributes (e.g., flood risk tolerance threshold) and mutual aid mechanism affect the flood evacuation process. Results indicated that: (1) The community density negatively affected the flood evacuation efficiency. The greater the density of the community, the longer the evacuation time. (2) There was a negative correlation between the flood risk tolerance threshold of residents and evacuation efficiency. (3) The proportion of vulnerable resident agents had opposite effects on the evacuation efficiency of different types of communities, which was to negatively affect low-density communities and positively affect high-density communities. (4) Mutual aid mechanism can reduce evacuation time in low-density communities, and the effect was more pronounced with a higher proportion of vulnerable resident agents in the community. These findings can help managers to develop better emergency evacuation management for urban communities.

Community flood resilience assessment frameworks: a review

In response to the inadequacy of flood control infrastructures under uncertainties, building community resilience has become a vital concern in modern flood risk management for flood mitigation and recovery options. Relatedly, there has been growing recognition of the importance of community flood resilience measurement, and several tools to measure resilience have been introduced since the turn of this century. However, overall yield from resilience works can be compromised if the measurements do not conform to theoretical basis. By identifying evaluation methodology which takes the multifaceted nature of resilience into account, this study analyzed existing community flood resilience measurement tools. The results show that the importance of assessing and enhancing community competence in flood resilience building is unnoticed by the majority of the analyzed frameworks. Adopting a participatory approach and measurement under uncertainties are overlooked by a significant proportion of the frameworks. Moreover, issues of spatial and temporal interdependencies have received less attention. Consequently, the multi faceted nature of resilience appears inadequately addressed in existing frameworks, and measurements of community flood resilience tend to be inconsistent. The study would support efforts being made to improve consistency and effectiveness community flood resilience measurements and to operationalize the concept of resilience in flood disaster management.

“Garbage in, Garbage Out” Does Not Hold True for Indigenous Community Flood Extent Modeling in the Prairie Pothole Region

Extensive land use changes and uncertainties arising from climate change in recent years have contributed to increased flood magnitudes in the Canadian Prairies and threatened the vulnerabilities of many small and indigenous communities. There is, thus, a need to create modernized flood risk management tools to support small and rural communities’ preparations for future extreme events. In this study, we developed spatial flood information for an indigenous community in Central Saskatchewan using LiDAR based DEM and a spatial modeling tool, the wetland DEM ponding model (WDPM). A crucial element of flood mapping in this study was community engagement in data collection, scenario description for WDPM, and flood map validation. Community feedback was also used to evaluate the utility of the modelled flood outputs. The results showed the accuracy of WDPM outputs could be improved not only with the quality of DEM but also with additional community-held information on contributing areas (watershed information). Based on community feedback, this accessible, spatially-focused modeling approach can provide relevant information for community spatial planning and developing risk management strategies. Our study found community engagement to be valuable in flood modeling and mapping by: providing necessary data, validating input data through lived experiences, and providing alternate scenarios to be used in future work. This research demonstrates the suitability and utility of LiDAR and WDPM complemented by community participation for improving flood mapping in the Prairie Pothole Region (PPR). The approach used in the study also serves as an important guide for applying transdisciplinary tools and methods for establishing good practice in research and helping build resilient communities in the Prairies.

Simulating Behavioral Influences on Community Flood Risk under Future Climate Scenarios.

Flood risk is a function of both climate and human behavior, including individual and societal actions. For this reason, there is a need to incorporate both human and climatic components in models of flood risk. This study simulates behavioral influences on the evolution of community flood risk under different future climate scenarios using an agent-based model (ABM). The objective is to understand better the ways, sometimes unexpected, that human behavior, stochastic floods, and community interventions interact to influence the evolution of flood risk. One historic climate scenario and three future climate scenarios are simulated using a case study location in Fargo, North Dakota. Individual agents can mitigate flood risk via household mitigation or by moving, based on decision rules that consider risk perception and coping perception. The community can mitigate or disseminate information to reduce flood risk. Results show that agent behavior and community action have a significant impact on the evolution of flood risk under different climate scenarios. In all scenarios, individual and community action generally result in a decline in damages over time. In a lower flood risk scenario, the decline is primarily due to agent mitigation, while in a high flood risk scenario, community mitigation and agent relocation are primary drivers of the decline. Adaptive behaviors offset some of the increase in flood risk associated with climate change, and under an extreme climate scenario, our model indicates that many agents relocate.

Evidence from Measuring Community Flood Resilience in Asia

Disaster risk and subsequent loss and damage in Asia are increasing at an alarming rate, threatening socioeconomic gains. Arresting this rapid increase in exposure requires risk-informed development and urban planning—a challenging proposition complicated by multiple economic and political incentives. To reduce these risks, action at the national and regional levels must be complemented by action at the community level. Measuring community disaster resilience can help lead to novel and systemic investments that build community resilience. Our analysis of community flood resilience data finds deficiencies and potential for substantial improvements in community flood resilience investment across the region, with different recommendations for urban, peri-urban, and rural locations. Our evidence from case studies shows that interventions prioritized by the measurement-informed process are more likely to succeed and be sustainable and have cobenefits for community development.

First insights from the Flood Resilience Measurement Tool: A large-scale community flood resilience analysis

A major gap in understanding community flood resilience is a lack of an empirically validated measure of it. To fill this gap, the Zurich Flood Resilience Alliance developed an approach to test and validate a measure of community flood resilience. The approach holistically measures a set of sources of community flood resilience and, when floods occur, it also measures resilient outcomes (level of loss and recovery time). The data is collected and assessed via a web and mobile based measurement tool. Here we report results from data collected in 118 communities across 9 countries using mixed method data collection approaches. This study represents the first large scale analysis of systemic and replicable flood resilience baseline data. The learnings from the analysis provide insights into sources of community flood resilience as a first step to building an evidence based approach to building effective flood resilience capacity.

Indigenous knowledge for enhancing community resilience: An experience from the south-western coastal region of Bangladesh

Traditional lifestyle of depending on the natural process, without trying to altering it, is close to the recent idea of sustainability which refers to an attempt to interlink and emulate natural processes with human activities. The Western-Euro-centric notions of science and scientific knowledge and technologies usually open opportunities to control natural processes with infrastructures to maximize economic benefits. Emphasis on short-term economic growth through the option of controlling or altering natural processes may hinder community resilience, referred as ability to resist, adapt with and recover from negative and devastating impacts of any natural process.Through employing oral history methodology in a case from Bangladesh, this article investigate the consequences of incorporating Western-Euro-centric scientific knowledge and traditional practices based on indigenous knowledge for managing water resources and resulted impacts on community flood resilience. In this case, to protect the lands from seasonal inundation, structural interventions were implemented and it resulted an environmental disaster, where cultivable lands and settlements got suffered from prolonged drainage congestion and water-logging problem. The problem was resulted due to some donor funded interventions on the river system since sixties with construction of polders/enclosures, utilizing Western-Euro-centric knowledge, which de-linked the floodplain wetlands from rivers. Whereas, indigenous approach of managing the tidal waves with temporary structures was scientifically proved its suitability to make those areas free from drainage congestion and water-logging problem. The article ends with a conclusion that, to get a resilient community, we need to combine the benefits of indigenous knowledge and modern technological solutions.

A review of the community flood risk management literature in the USA: lessons for improving community resilience to floods

This study systematically reviews the diverse body of research on community flood risk management in the USA to identify knowledge gaps and develop innovative and practical lessons to aid flood management decision-makers in their efforts to reduce flood losses. The authors discovered and reviewed 60 studies that met the selection criteria (e.g., study is written in English, is empirical, focuses on flood risk management at the community level in the USA, etc.). Upon reviewing the major findings from each study, the authors identified seven practical lessons that, if implemented, could not only help flood management decision-makers better understand communities’ flood risks, but could also reduce the impacts of flood disasters and improve communities’ resilience to future flood disasters. These seven lessons include: (1) recognizing that acquiring open space and conserving wetlands are some of the most effective approaches to reducing flood losses; (2) recognizing that, depending on a community’s flood risks, different development patterns are more effective at reducing flood losses; (3) considering the costs and benefits of participating in FEMA’s Community Rating System program; (4) engaging community members in the flood planning and recovery processes; (5) considering socially vulnerable populations in flood risk management programs; (6) relying on a variety of floodplain management tools to delineate flood risk; and (7) ensuring that flood mitigation plans are fully implemented and continually revised.

Heading for the Hills? Effects of Community Flood Management on Local Adaptation to Flood Risks

The Community Rating System (CRS) program was implemented by the U.S. Federal Emergency Management Agency (FEMA) in 1990 as an optional program to encourage communities to voluntarily engage in flood mitigation initiatives. This article uses national census tract‐level data from 1980 to 2010 to estimate whether CRS participation and flood risk affect a community's local patterns of population change. We employ an instrumental‐variables strategy to address the potential endogeneity of CRS participation, based on community‐scale demographic factors that predict when a tract's host community joins the CRS. The results find significant effects of the CRS program and flood risk on population change. Taken together, the findings point to greater propensity for community‐scale flood management in areas with more newcomers and programs such as CRS stabilizing population, though not especially in flood‐prone areas. We observe the CRS neither displacing population toward lower‐risk areas nor attracting more people to flood‐prone areas.

A multi-criteria approach for assessing urban flood resilience in Tehran, Iran

Operationalizing the concept of urban disaster resilience is a major milestone toward understanding both the characteristics that contribute to the resilience of cities to natural hazards and the interactions required to build and sustain it. While the measurement of urban disaster resilience has recently gained much attention, there is so far no optimal approach for operationalizing this concept and therefore there is a need to conduct more empirical studies on what constitutes disaster resilience and how to assess it. In this study, a resilience assessment focuses on the inherent characteristics and capacities of Tehran in the context of flash floods from surface water or from the overflow of rivers. The measurement approach is based on constructing a composite index based on six resilience dimensions social, economic, institutional, infrastructural, community capital and environmental of community flood resilience. This follows by developing a hybrid multi-criteria decision-making method. The applied method is a combination of the AHP for prioritizing the selected indicators and the TOPSIS tools in order to get Tehran's urban districts ranked based on their resilience levels. Data were mostly from the Statistical Center of Iran and Tehran Municipality's accessible data sources. The results clarify that Districts 6 and 22 are comparatively the most resilient districts, while District 1 is the only district with the lowest level of resilience. Such place-based assessments have an opportunity to track community performance over time and provide the tool to decision-makers in order to integrate resilience thinking into urban development and resilience-oriented urban planning.

Flood insurance rate map for non-structural mitigation

December 2014 flooding in Kelantan river basin caused severe damage to economic and social infrastructure and dealt a serious blow to Kelantan state economies. Mitigation of flood disaster can be successful only when detailed knowledge is obtained about the vulnerability of the people, buildings, infrastructure and economic activities in a flood risk area. Therefore, to identify a community's flood risk, pre-disaster financial instrument will be introduced as non-structural mitigation measures know as flood insurance rate map. This instrument will be developed based on geospatial technology using satellite images, topographic surveys, cadastral map, type of community building such as residential or commercial and households’ income. Flood hazard maps and flood insurance rate map will provide the flood risk zone and flood insurance rate and premium coverage for the affected community. In additions it helps to determine the type of flood insurance coverage is needed since standard homeowners’ insurance doesn't cover flooding. Flood insurance rate map will provide affordable insurance for property owners, based on the lower the degree of risk state in flood hazard map, the lower the flood insurance premium. These insurance rate map are valuable to communities because it creates safer environments by reducing loss of life and decreasing property damage, allows individuals to minimize post-flood disaster disruptions and to recover quicker.

Factors and actors for enhancing community flood resilience

PurposeEnhancing community flood resilience is a critical aspect of flood risk management that requires a systematic process of capacity building through incorporating mitigation measures. The inhabitants of South Rishipara, a riverside settlement of Bangladesh, are accommodating themselves in a flood-prone location through modifying their built environment. The purpose of this study is to conduct a detailed investigation regarding the built environment development and find out roles of different actors and contributing factors for enhancing community flood resilience.Design/methodology/approachThis case study-based post-positivist research uses multiple lines of inquiries, which include focus group discussions, transect walks, in-depth semi-structured interviews, pair-wise comparisons and a questionnaire survey, mostly in a participatory appraisal manner to obtain data about community experiences and perceptions.FindingsAbout 66.7 per cent of respondents identified themselves as severely affected by flood before the recent development with increased elevation of land, flood protection walls, reclaimed land from the river, underground drainage system, a new layout of plots and houses of better quality. In the post-development situation, not a single respondent identified him/ her in that condition. “Coordination and cooperation among GOs, NGOs and donor agency” (GO: governmental organization; NGO: nongovernmental organization) and “awareness about the flood vulnerability” were identified as key factors and the NGO was identified as the key actor for enhancing community flood resilience by the survey participants.Originality/valueThis research, through exploring the nuanced relationship between built environment development and community resilience, will contribute to address uncertainties associated with community capacities to respond to risks.

Effects of Flood Control Strategies on Flood Resilience Under Sociohydrological Disturbances

AbstractA community capacity to cope with flood hazards, or community flood resilience, emerges from the interplay of hydrological and social processes. This interplay can be significantly influenced by the flood control strategy adopted by a society, i.e., how a society sets its desired flood protection level and strives to achieve this goal. And this interplay can be further complicated by rising land‐sea level differences, seasonal water level fluctuations, and economic change. But not much research has been done on how various forms of flood control strategies affect human‐flood interactions under these disturbances and therefore flood resilience in the long run. The current study is an effort to address these issues by developing a conceptual model of human‐flood interaction mediated by flood control strategies. Our model extends the existing model of Yu et al. (2017), who investigated the flood resilience of a community‐based flood protection system in coastal Bangladesh. The major extensions made in this study are inclusions of various forms of flood control strategies (both adaptive and nonadaptive ones), the challenge of rising land‐sea level differences, and various high tide level scenarios generated from modifying the statistical variances and averages. Our results show that adaptive forms of flood control strategies tend to outperform nonadaptive ones for maintaining the model community's flood protection system. Adaptive strategies that dynamically adjust target flood protection levels through close monitoring of flood damages and social memories of flood risk can help the model community deal with various disturbances.

Psychosocial Factors and Quality of Life Among Flood Victims in Malaysia

Objective - The study seeks to determine the relationship between psychosocial factors, namely social support, impression management and emotional factors (stress, anxiety and depression), with quality of life among flood victims. The Conservation of Resources Stress Approach Model and The Social Support Deterioration Model suggest that quality of life is dependent upon these psychosocial factors. Methodology/Technique - The cross-sectional study examined 1300 flood victims in flood prone areas in Malaysia. The Multidimensional Scale of Perceived Social Support, The Bolino and Turnley Impression Management Scale and Depression, Anxiety and Stress Scale questionnaires were used to measure the psychosocial factors, while The WHO Quality of Life instrument was used to measure quality of life. The results were analysed using Pearson Correlations. Findings - The findings demonstrate that, in general, psychosocial factors are associated with quality of life. Social support dimensions and emotional factor dimensions were significantly correlated with quality of life. In addition, two dimensions of impression management were correlated with quality of life. The findings are consistent with the psychosocial theory that implies an overall relationship between the variables studied. Novelty – This study suggests that there is much to be done in terms of community flood education in Malaysia, as well as training for emergency aid providers to decrease the likelihood of negative effects of psychosocial factors on individuals' quality of life. A psychosocial support programme is recommended to enhance overall quality of life for flood victims. Type of Paper - Empirical Keywords: Psychosocial; Social Support; Impression Management; Stress; Anxiety; Depression; Quality of Life. JEL Classification: I30, I31.

An Agent‐Based Model of Evolving Community Flood Risk

Although individual behavior plays a major role in community flood risk, traditional flood risk models generally do not capture information on how community policies and individual decisions impact the evolution of flood risk over time. The purpose of this study is to improve the understanding of the temporal aspects of flood risk through a combined analysis of the behavioral, engineering, and physical hazard aspects of flood risk. Additionally, the study aims to develop a new modeling approach for integrating behavior, policy, flood hazards, and engineering interventions. An agent-based model (ABM) is used to analyze the influence of flood protection measures, individual behavior, and the occurrence of floods and near-miss flood events on community flood risk. The ABM focuses on the following decisions and behaviors: dissemination of flood management information, installation of community flood protection, elevation of household mechanical equipment, and elevation of homes. The approach is place based, with a case study area in Fargo, North Dakota, but is focused on generalizable insights. Generally, community mitigation results in reduced future damage, and individual action, including mitigation and movement into and out of high-risk areas, can have a significant influence on community flood risk. The results of this study provide useful insights into the interplay between individual and community actions and how it affects the evolution of flood risk. This study lends insight into priorities for future work, including the development of more in-depth behavioral and decision rules at the individual and community level.

Erratum to: Assessment of coastal communities’ vulnerability to floods using indicator-based approach: a case study of Greater Accra Metropolitan Area, Ghana

Coastal towns along the coast of Africa are among the most vulnerable to climate change impacts such as flooding and sea level rise. Yet, because coastal conditions in many parts of the region are poorly understood, knowledge on which population groups are at the most risk is less known, particularly in the Greater Accra Metropolitan Area (GAMA) of Ghana, where the capital city Accra is located. Without adequate information about the risk levels and why, the implementation of locally appropriate adaptation plans may be less effective. This study enriches our understanding of the levels of flood risks along the coast of GAMA and contributes knowledge to improve understanding of place-specific adaptation plans. The study uses data from a 300-household survey, stakeholder meetings, and interviews with local community leaders to construct an integrated vulnerability index. The index includes seven components made up of: dwelling type; house and house environment; household socioeconomic characteristics; experience and perception of flood risk; household and community flood adaptation strategies; house location, and physical characteristics. Our findings show that exposure to floods, particularly from local flash floods is relatively high in all communities. However, significant differences in sensitivity and adaptive capacity of the communities were observed due to differences in location, socioeconomic characteristics, and perception of risks to flooding and sea level rise. The complexity of factors involved in the determination of local-level vulnerability requires that the implementation of adaptation strategies needs to involve cross-sectorial partnerships, involving local communities, in building a comprehensive multi-risk adaptation strategy.

Development and testing of a community flood resilience measurement tool

Abstract. Given the increased attention on resilience strengthening in international humanitarian and development work, there is a growing need to invest in its measurement and the overall accountability of resilience strengthening initiatives. The purpose of this article is to present our framework and tool for measuring community-level resilience to flooding and generating empirical evidence and to share our experience in the application of the resilience concept. At the time of writing the tool is being tested in 75 communities across eight countries. Currently 88 potential sources of resilience are measured at the baseline (initial state) and end line (final state) approximately 2 years later. If a flood occurs in the community during the study period, resilience outcome measures are recorded. By comparing pre-flood characteristics to post-flood outcomes, we aim to empirically verify sources of resilience, something which has never been done in this field. There is an urgent need for the continued development of theoretically anchored, empirically verified, and practically applicable disaster resilience measurement frameworks and tools so that the field may (a) deepen understanding of the key components of disaster resilience in order to better target resilience-enhancing initiatives, and (b) enhance our ability to benchmark and measure disaster resilience over time, and (c) compare how resilience changes as a result of different capacities, actions and hazards.

Sustainable flood memories, lay knowledges and the development of community resilience to future flood risk

The paradigm shift to more distributed flood risk management strategies in the UK involves devolved responsibilities to the local, and the need to enhance risk ownership by communities. This poses questions about how communities build resilience to future flood risk, and how agencies support these processes. This paper explores results from interdisciplinary research on ‘sustainable flood memory’ in the context of effective flood risk management as a conceptual contribution to a global priority. The project aimed to increase understanding of how flood memories provide a platform for developing and sharing lay knowledges, creating social learning opportunities to increase communities’ adaptive capacities for resilience. The paper starts by conceptually framing resilience, community, lay knowledge and flood memory. It then explores key themes drawn from semi‐structured interviews with floodplain residents affected by the UK summer 2007 floods in four different settings, which contrasted in terms of their flood histories, experiences and kinds of ‘communities’. Sustainable flood memories were found to be associated with relational ways of knowing, situated in emotions, changing materiality and community tensions. These all influenced active remembering and active forgetting. The paper reflects on varying integrations of memory, lay knowledges and resilience, and critically evaluates implications of the sustainable flood memory concept for the strategy, process and practice of developing community flood resilience. Given the concept's value and importance of ‘memory work’, the paper proposes a framework to translate the concept practically into community resilience initiatives, and to inform how risk and flood experiences are communicated within communities.

Technologies to Support Community Flood Disaster Risk Reduction

Floods affect more people globally than any other type of natural hazard. Great potential exists for new technologies to support flood disaster risk reduction. In addition to existing expert-based data collection and analysis, direct input from communities and citizens across the globe may also be used to monitor, validate, and reduce flood risk. New technologies have already been proven to effectively aid in humanitarian response and recovery. However, while ex-ante technologies are increasingly utilized to collect information on exposure, efforts directed towards assessing and monitoring hazards and vulnerability remain limited. Hazard model validation and social vulnerability assessment deserve particular attention. New technologies offer great potential for engaging people and facilitating the coproduction of knowledge.

Scenario-based community flood risk assessment: a case study of Taining county town, Fujian province, China

Community-based flood risk assessment has gained increasing attention as communities are the first responder to disasters and thus the key player of disaster risk reduction. In this study, using a scenario-based risk model and the combination of 1D/2D hydrodynamic model and participatory geographic information system, a methodology for flood risk assessment at the community level is put forward, including flood hazard assessment, exposure analysis, vulnerability assessment, and loss estimation and risk profiling. With this methodology, a set of potential damage/loss scenarios with various probabilities of flood occurrence can be established, and the spatial distribution of the loss in different probabilities can be mapped as well. It is proved that the proposed methodology is effective in flood risk assessment at the community level. The case study of Taining county town shows that the threats and impacts of flood disaster on the community are significant, and it is necessary to take structural and non-structural measures to reduce the flood risk.