Analysis Of Cause And Study On Liability Assessment Of Landslide And Debris Flow Hazards In Yunnan Province

Yunnan province is located in the plate boundary. Tectonic movement is changeful, earthquake activity is frequent, and terrain is very steep, cutting and broken. Stratigraphic lithology is complex, climate types are variety, unique local heavy rain is frequent, ecological environment is fragile. Landslide and debris flow have large number and wide area, the activity is intense and abruptness is strong. They are the dominant hazards for leading to the life and property lost and economic and social development restricted. And the study on subsequently factors of landslides and debris flows in Yunnan province has a very important significance in terms of disaster forecast and disaster reduction. Based on this, this paper is taking Yunnan province as the study area and landslide and debris flow as the research object, based on the project of “Remote sensing and geological comprehensive interpretation on disaster in prone areas”. 1:500,000 geological map and high resolution DEM data interpretation, and finishing 11596 landslides, 2841 debris flow data. Subsequently factors of geological disasters’ characteristic have carried on the qualitative and quantitative analysis. And the liability of landslides and debris flows in Yunnan province has evaluated. The following results:1. The preliminary quantitative analysis of the distribution characteristics and regulars of geological disasters.Geological disasters in Yunnan province are given priority to with landslide, debris flow follow. Landslide sliding, traction type landslide and goes on to landslide are given priority to; Debris flow is given priority to with mud-rock flow and water-stone flow. Mainly distributed regions include Zhao tong, Pu er, Chuxiong, honghe and Dali. The relative number density, relative area density, the relative volume density and comprehensive strength index distribution in different geological disasters area has different distribution state.2. The influences on disasters of main factors are analyzed subsequentlyThe influences of main factors controlling landslides and debris flows occurred in the province including topography(height, slope, and aspect), the types of slope structure, stratum lithology, geological structure, water system, vegetation coverage, etc are analyzed. Main inducing factors of landslide and debris flow in Yunnan province are rainfall(short-term rainfall), human activities(vegetation destruction, building roads, etc.).3. Set up a systematic evaluation index system of geological disasters in Yunnan province, through qualitative and quantitative method to analyze the relationship between the geological disasters and subsequently factors. Using the ATP and expert scoring method generalized classification and assignment of evaluation factors, and calculate the weight of each factor. Based on GIS raster superimposed calculation, layer overlay, various factors are prone to partition map. Disasters in Yunnan province were analyzed, and disaster prone was divided four partitions: high, medium, low and extremely low.