Flood risk assessment and coping capacity with flood in Central Vietnam

As the socio-economic conditions are developing and living standards are improving in several countries which are heavily affected by flood hazard, including Vietnam, to help decision-makers in examining the potential risks and damages associated with uncertain future flood hazards and identifying the most appropriate structural and nonstructural risk prevention measures, it is necessary to apply appropriate risk assessment methodologies. This study starts from flood hazard maps estimated in Quang Ngai province, in central Vietnam, for different return periods in terms of depth, duration and velocity using the Flo-2D hydrodynamic model. Then, for vulnerability assessment and exposure estimation, direct tangible and intangible costs are estimated, based on more than 386 responses of local people to 35 questions in a questionnaire directly related to flood risk and preparedness, including socioeconomic and cultural aspects. Field surveys and technical reports were used for a better understanding of the questionnaire responses. In this way damage functions for residential area, paddy rice, road network, death and injured people are fitted to local conditions providing some results which differ, in part, from those found in the technical literature showing how local communities and people developed adaptive and coping capacity strategies. Finally, the total tangible and intangible damages at each point of a 90 m x 90 m resolution grid in the study area are mapped, indicating the risk levels. In this way, a more comprehensive knowledge on negative effects of floods is carried out, providing an important input to flood management plans in order to mitigate flood damages.