Landslide Susceptibility Assessment of Longchuan County Based on GIS and Information Value Model

The geological environment of Longchuan County, Yunnan Province, is fragile and vulnerable to landslides. Analyzing the susceptibility of regional landslide hazards is of great significance to prevent and control the landslides in this area. Ten evaluation factors are established. They are elevation, slope, slope direction, section curvature, plane curvature, normalized vegetation index, distance from water system, fault distance, lithology and road distance. Landslide susceptibility evaluation is assessed by using information value model and Geographic Information System(GIS). The results show that the high landslide susceptibility zones are mainly located in the north, southeast and southwest of the study area; the moderate landslide susceptibility zones are mainly in the central, eastern and western parts of the study area; the low landslide susceptibility zones are mainly in Longba Township, most of Chengzizhen and northwest of Hu Sa Achang; the extremely low landslide susceptibility zones are mainly located in the central and urban areas of Qingping,part of the central part of Chenzi and most of Zhangfeng. 83.56% of the landslide hazards are in the middle and high susceptible zones, and the area of landslide increases with the increase of the susceptibility grade. The area of the middle and the high landslides susceptible zones accounts for 22.79% and 58.13% respectively of the total study area.The results are consistent with the actual distribution of landslide hazards, which can provide theoretical reference for disaster prevention and mitigation in the study area.