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

The effects of flooding can be very serious, especially in developing countries, where rapid urbanization and socio-economic development increases risk. Reliable information is crucial to support decision-makers develop appropriate strategies to reduce flood risk. This article aims to develop a framework for assessing flood risk and adaptive capacity, based on a bottom-up approach, in Vietnam’s Gianh River watershed. 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 flood risk is high in areas with high population and construction density. Both the ability to access resources and communities' flood-risk 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 flood-risk management in the context of climate change and urbanization in other regions. The study also fills a gap in the knowledge of the negative effects of flooding. From a methodological standpoint, this study underlines the importance of using hydraulic models and socio-economic surveys in flood-risk management.