Flood damage assessments based on entropy weight - grey relational analyses

Flooding can cause extensive damage. Accurate flood damage assessments are needed to formulate effective prevention and mitigation measures. A flood damage assessment index was established based on such factors from the Chinese Flood Damage Assessment Standard (SL579-2012) as the death toll, affected population, crop damage area, direct economic loss, house damage, and economic losses of water conservancy facilities. The grey relational analysis and entropy weight methods were used to develop a damage assessment method that assessed and classified rainstorm and flood damage in China using annual flood data from 2014 to 2018. The assessment results and actual evaluations were combined to develop ways to mitigate and prevent rainstorm and flood damage. The results show that national rainstorm disasters with high entropy weight - grey relational degrees have been concentrated in the southeast and northwest regions and that flood prevention and control should focus on urban and desert flood control. The national rainstorm disaster entropy weight - grey relational degree was highest in 2016 which saw many serious floods. © 2022, Tsinghua University Press. All right reserved.