Hazard Assessment of Geological Disaster in Nanning City Based on Factor Contribution Rate Mode

Taking geological disasters in Nanning as a case study, 6 factors including geological lithology, slope, elevation, aspect, NDVI and land use are selected to construct the index system of geological hazard zoning. The factor contribution rate model is used to calculate the self-weight and interweigh of each factors, and the geological disaster risk evaluation model is established finally. Based on GIS platform, after obtaining each indicator analysis data, the comprehensive indexes for geological disaster risk zonings in each grid are calculated, and then the risk zonings of geological disaster in Nanning are divided into different zones according to calculated indexes. The results show that the comprehensive indexes of geological disaster risk zonings range from 1.18368 to 19.8259, and the risk zonings of geological disaster in Nanning can be divided into five: safety area, low dangerous area, moderate dangerous area, high dangerous area and extremely high dangerous area. The extremely high dangerous area is mainly distributed in the central of Nanning, human activity is relatively strong, and the area is 5274.189 km2 accounting for 6.84% of the total. The high dangerous area is mainly distributed in the south and south-east of Nanning and the area is 9859.604 km2 accounting for 12.79% of the total area. The moderate dangerous area is mainly distributed in the southwest and north of Nanning and the area is 12358.724 km2, accounting for 16.04% of the total area. The low dangerous area is mainly distributed in the east of Nanning and the area is 16198.205 km 2 , accounting for 21.02% of the total. The safety area is large and the area is about 33379.713 km 2 , accounting for 43.31% of the total area. Research results can provide the basis for geological disaster prevention and mitigation of Nanning, which is of great significance for reducing and preventing geological disasters. * 通讯作者。