Research on Chongqing Mountain Flood Disaster Risk Assessment System Based on AHP-GIS

Abstract The risk of mountain flood disasters is the fundamental factor restricting the occurrence of disasters. The analysis and assessment of disaster risks is the basis for disaster risk management. Through the investigation of mountain flood disasters from 2013 to 2015, the basic information such as hydrometeorology, topography, socio-economic and mountain flood disaster prevention and control situation in mountain flood disaster prevention and control areas were found out. Taking the city of mountains-Chongqing as an ex-ample, this paper considered the results of mountain flood disaster investigation and evaluation in recent years, and divided the risk evaluation indicators into two types of first-level indicators: rainfall and under-lying surface, and the secondary indicators were subdivided into comprehensive rainstorm indicators, critical rainfall, topographic relief, land use convergence capacity, soil texture and river network density. Using AHP to set the weight coefficient of each level indicators, those showed that heavy rain conditions, critical rainfall and topographic relief were important factors impacting the mountain flood disasters, and the land use convergence capacity had the minimum weight coefficient. Through GIS superposition analysis, the risk index of mountain flood disasters in the region were obtained. The western, southeastern and northeastern Chongqing were high risk areas for mountain flood disasters, which provided decision-making basis for mountain flood disaster risk management.