SPATIOTEMPORAL DISTRIBUTION AND INFLUENCING FACTORS OF GEOLOGICAL DISASTERS IN MOUNTAINOUS AREAS: A Case Study of Mabian County in Sichuan Province

To reduce the occurrence of geological disasters, minimize the loss of human life and property and the destruction of environment, and improve the ability of disaster prevention and reduction in geological disaster area, through field survey, data statistics and GIS spatial analysis, the qualitative and quantitative combination method is used to study the relationship between the spatiotemporal distribution of geological disasters and three categories of factors, i.e. landform, geological structure and rainfall, as well as eight subcategories such as elevation, slope aspect, slope gradient, slope type, lithology, fault, rainfall and human activities. The results indicate that the geological disasters in Mabian County are mainly landslides, followed by collapses, and least debris flows, showing uneven spatial and temporal distribution. The sensitive intervals of topographic factors include the elevation of 700-900 m, slope aspect of east and southeast, slope gradient of 20-25° and slope type of mainly convex slope. The sensitive geological structural factors include the lithology of mainly mudstone, and tectonic zones less than 1 km away from the fault centerline. The sensitive interval of rainfall is 1100-1300 mm in low mountain area and 1300-1500 mm in middle and high mountain areas. Human activity is also a nonnegligible factor.