Exposure to Floods, Climate Change, and Poverty in Vietnam

Abstract. With 70 percent of its population living in coastal areas and low-lying deltas, Vietnam is highly exposed to riverine and coastal flooding. This paper examines the exposure of the population and poor people in particular to current and future flooding in Vietnam and specifically in Ho Chi Minh City, using new high-resolution flood hazard maps and spatial socioeconomic data. The national-level analysis finds that a third of today’s population is already exposed to a flood, which occurs once every 25 years, assuming no protection. For the same return period flood under current socioeconomic conditions, climate change may increase the number exposed to 38 to 46 percent of the population. Climate change impacts can make frequent events as important as rare ones: the estimates suggest a 25-year flood under future conditions can expose more people than a 200-year flood under current conditions. Although poor districts are not found to be more exposed to floods at the national level, the city-level analysis of Ho Chi Minh City provides evidence that slum areas are highly exposed. The results of this paper show the benefits of investing today in flood risk management, and can provide guidance as to where future investments may be targeted.