Risk assessment of rainstorm disasters under different return periods: A case study of Bohai Rim, China

Rainstorms are extreme events that have a serious impact on the safety of people's lives and property, and on socioeconomic development. Coastal areas have a large population and a high urban concentration tend to be areas that experience high levels risk of extreme precipitation. The present study uses the Bohai Rim, China, as a case study, and applies the copula joint function to daily precipitation data to calculate the probability of rainstorms under different return periods such that the hazard presented by each rainstorm disaster could be analyzed. Grid data of gross domestic product (GDP) per land area (km(2)) and population density were selected to calculate and assess the associated respectively levels of exposure and vulnerability. The risk of occurrence of a rainstorm disaster was analyzed according to the disaster risk assessment paradigm of the United Nations Office for Disaster Risk Reduction (UNDRR). The results showed that the risk of a rainstorm disaster under different return periods in the Bohai Rim gradually decreased from the southeast coastal region towards the northwest inland area. Our study provides a scientific basis for governments to improve disaster prevention and reduction, and can assist in the formulation of emergency management countermeasures.