Bottom-up approach for flood-risk management in developing countries: a case study in the Gianh River watershed of Vietnam

Abstract

Flood effects are very serious, especially in developing countries where they are at high risk due to urbanization and socio-economic development. Reliable information is crucial to support decisionmakers or planners to develop appropriate strategies to reduce ood risk. This article aims to develop a theoretical framework for assessing ood risk and adaptive capacity based on a bottom-up approach, in the Gianh River watershed of Vietnam, considered a very important task for ood risk management. Flood risk was computed by combining hazard, exposure, and vulnerability using hydrodynamic modeling and the Analytic Hierarchy Process method. The adaptive capacity of the population was assessed via interviews with 298 inhabitants. The results show that ood risk is high in areas with high population and construction density. Both the ability to access resources and communities' perceptions are important factors in improving the capacity to adapt. This study can provide an important theoretical framework complementing the existing literature and supporting studies related to ood risk management in the context of climate change and urbanization in other regions. Besides, the study lls in a gap in the knowledge of negative ood effects, providing important inputs for decision-makers to develop appropriate strategies for reducing damage in Vietnam and other countries in the world. From a methodological start point, this study underlines the importance of using hydraulic models and socioeconomic surveys in ood risk management.

Flood Impacts on Household Livelihoods and Its Mitigation Strategies: Focus of Gelana Woreda, Oromia, Ethiopia

“…According to Gashaw & Legesse (2011) and Nguyen et al (2023), the most common natural disasters are oods, which are caused by the effects of climate change on both excessively high precipitation and rising sea levels. In the same way, a disaster requires a "cause event" to occur, even while a population remains at risk for a long period.…”

“…The ability of various soil types to absorb water varies. ''In ltration is a fundamental component that greatly in uences the rainfall-runoff process and plays a vital role in determining the amount of water that will be available for surface runoff after a rainstorm event,'' emphasizes (Nguyen et al, 2023). The total number of pores (soil porosity), grain size distribution and particle size distribution, size distribution and aggregate structure of the soil, and amount of organic matter in the soil are the soil factors that affect the in ltration rate (Cassol et al, 2018; Corral-Pazos-de-Provens et al, 2023).…”

“…A number of catchment area features must be analyzed to determine hazards, which include identifying ood zones, evaluating the return period associated with being submerged, determining the depth and length of submergence, and determining the speed of the current. Drainage is formed by vegetation, land use, and rainfall patterns; its concentration is in uenced by topographical, geological, and physical factors (Nguyen et al, 2023).…”

A Novel Flood Risk Analysis Framework Based on Earth Observation Data to Retrieve Historical Inundations and Future Scenarios

“…A good alternative is represented by data-driven models, which attempt to identify potential flood areas and risk by defining functional relationships between hydro-morphological variables and the presence or absence of inundations [18]. Hybrid models integrating a data-driven risk framework and hydraulic variables are emerging as a new beneficial approach; for instance, Nguyen et al [20,21] combined machine learning and hydrodynamic modeling for assessing risk and predicting risk development.…”

“…Most importantly, there is an urgent need for extensive flood education and knowledge dissemination in communities to foster risk awareness among residents, which is currently lacking due to infrequent floods catching them off guard. Accordingly, a bottom-up risk management approach combined with socio-economic surveys aimed at improving the adaptive capacity of residents could be implemented, especially in developing countries [20].…”