The Development Characteristics Of Landslides And The Disaster Pregnant Environment Of The High Incidence Area In Yunnan Province

Yunnan Province,located in the southwest of China,has a fragile ecological geological environment,and is one of the areas with the most serious landslide geological disasters.Based on the analysis of the characteristics of landslide development and the disaster pregnant environment of the high-risk area in Yunnan Province,the paper has provided theoretical reference for the prevention and control of landslide geological disasters in Yunnan Province.This paper discusses the development trend,spatial distribution pattern and spatial density characteristics of landslides in Yunnan Province by using three methods: trend surface analysis,nearest neighbor analysis and nuclear density analysis.On the basis of these three methods,the high-risk areas of landslides in Yunnan Province are delineated,and the soft GIS is used.The sensitivity of hazard factors in the high-risk areas has been analyzed with the deterministic coefficient model,and the hazard environment in the high-risk areas has been summarized.The following achievements and understandings have been achieved:(1)The development characteristics of landslide geological hazards in the whole province are summarized.Qujing City has the largest number of landslides in Yunnan Province,and Xishuangbanna has the least.The number of landslides is relatively large in the northeast and northwest of Yunnan,but less in the southwest of Yunnan.The geological hazards of landslides in Yunnan Province are mainly small-scale,and the number of small-scale landslides in each state and city is far more than that of medium-sized,large-scale and extra large-scale landslides.(2)The spatial distribution characteristics of landslide geological hazards in the whole province are analyzed.The landslide geological hazards in the whole province are strong in the north and weak in the south,which are developed in all counties of the province.The number and total damage area of landslide geological hazards in each county are gradually decreasing from the north to the south.From the perspective of the whole province,the spatial distribution of geological hazards of landslides in Yunnan Province is of aggregation type;from the perspective of Prefecture,the spatial distribution of geological hazards of landslides in Lincang City is of uniform type,and the spatial distribution of geological hazards of landslides in the remaining 15 prefectures and cities is of aggregation type.(3)Five high-risk areas of landslides in Yunnan Province are delineated based on the comprehensive comparative analysis of the distribution map,core density map,three-dimensional perspective map of landslides number,total failure area trend of each county in Yunnan Province and the results obtained by the nearest neighbor analysis method.(4)The sensitivity of disaster pregnant factors and the characteristics of disaster pregnant environment in the high incidence area of landslides in Yunnan Province are systematically analyzed.Nine factors,such as elevation,gradient,slope direction,curvature,annual average rainfall,rock hardness,distance from river,distance from fault and distance from road,are selected to analyze the sensitivity of the disaster pregnant environment factors,and the characteristics of the disaster pregnant environment in each high-risk area are preliminarily summarized in combination with the geographical and geological environment,social and economic status and other factors.