Flood risk assessment combining the historical disaster statistics method with the index system method

Abstract

ABSTRACT Flood risk assessment is an important aspect of flood management, and we combined the historical disaster statistics method with the index system method to assess the flood risk in Hubei Province, China. Our methodology includes collecting historical flood disaster data to assess the flood hazard by calculating degree and trend of disaster from flood disasters in each geographical unit. Meanwhile, we selected relevant indicators such as elevation difference, distance to the water body, gross domestic product (GDP), population, and proportion of the construction land to measure flood susceptibility, and the weights for these indicators are determined combining the analytic hierarchy process (AHP) and the entropy weight method (AHP_entropy). Then, a risk assessment model is developed by integrating the hazard and susceptibility at a high-resolution grid scale of 1 km×1 km. The results show that about 55.6% of the area of Hubei Province falls into the medium-high risk category.