Analysis On Influencing Factors And Causes Of Landslide And Debris Flow In Guizhou Province

In order to improve the economic development of Guizhou,Guizhou province follows the development goal of“Clear waters and lush mountains are invaluable assets”,and has successively established the national big data industry center,cultural tourism and health care industry,and promoted the economic development by creating a green ecological and economic mode.However,the complex geological environment of Guizhou province leads to frequent soil erosion in this area,which brings certain challenges to the economic and social stability of Guizhou Province.In many soil erosion,landslide and debris flow are the most prominent problems.Therefore,how to effectively carry out soil erosion control,strengthen soil and water conservation and ecological environment construction,has important guiding significance for the development of disaster prevention and reduction in the next step of Guizhou Province.As the systematically studying the characteristics of soil erosion in Guizhou,landslide and debris flow as the research object,in full after the help of the predecessors’research ideas and methods,selection of Geological petrofabric,Slope,Rainfall,Fault zone,Elevation,NDVI,Slope to seven evaluation factors,using the analytic hierarchy process(AHP),the optimal sequence diagram method to determine the weights,hazard-formative factors Finally,the evaluation model of landslide debris flow susceptibility is established and the zoning map of landslide debris flow susceptibility is obtained.It provides basic data for soil and water conservation,soil erosion and disaster prevention and mitigation in the study area.The following results were obtained through systematic analysis:(1)By analyzing the influencing factors and causes of landslide and debris flow in Guizhou province,the prone areas of landslide and debris flow in Guizhou province are divided into four types:extremely low-prone area,low-prone area,medium-prone area and high-prone area,which reflects the regional distribution law of potential areas of landslide and debris flow in Guizhou Province.(2)The weight of each influence factor of landslide and debris flow in Guizhou province is calculated by using analytic hierarchy process and sequence diagram method,so as to make the evaluation more scientific and reliable through comparison.The results show that there is a certain difference between the two methods in susceptibility analysis,indicating that the scoring method has a certain degree of subjectivity.Although the specific values vary,the overall scale is consistent.(3)In terms of weight comparison of each factor,the weight ranking obtained by the two methods of comprehensive analytic hierarchy process(AHP)and order diagram method is the same.The order of importance sensitivity of landslide factors is Slope>Geological rock group>Rainfall>Fault zone>Elevation>NDVI>Slope aspect.The order of importance sensitivity of debris flow factors is Rainfall>Slope>Geological rock group>Elevation>NDVI>Fault zone>Slope aspect.(4)The area of extremely low landslide prone area is 37449.60 km~2,accounting for21.25%of the whole region;The low-risk area covers 64141.84 km~2,accounting for 36.40%of the total area of Guizhou Province.The area of medium-susceptible area is 51357.84 km~2,accounting for 29.15%of the total area of the province.The area of high susceptibility area is23255.60 km~2,accounting for 13.20%of the whole region of Guizhou Province.The area of very low risk area of debris flow is 10753.60 km~2,accounting for 6.11%of the whole region.The low-risk area covers 76,546.08 km~2,accounting for 43.44%of the total area of Guizhou Province.The area of medium-prone area is 78482.48 km~2,accounting for 44.54%of the province.The area of high susceptibility area is 10422.73 km~2,accounting for 5.91%of the whole region of Guizhou Province.(5)The area of extremely low landslide prone area is 35134.28 km~2,accounting for19.94%of the whole region;The area of low-risk area is 65159.76 km~2,accounting for 36.98%of the total area of Guizhou Province.The area of medium-prone area is 64,489.20 km~2,accounting for 36.60%of the province;The area of high susceptibility area is 21989.76 km~2,accounting for 12.48%of the whole region of Guizhou Province.The area of very low risk area of debris flow is 10554.38 km~2,accounting for 5.99%of the whole region.The area of low risk area is 73581.12 km~2,accounting for 41.76%of the total area of Guizhou Province.The area of medium-susceptible area is 81210.58 km~2,accounting for 46.09%of the province.The area of high susceptibility area is 10853.92 km~2,accounting for 6.16%of the whole region of Guizhou Province.(6)In terms of analysis and discussion,no matter how high the single disaster factor is,it will not induce disasters,and the occurrence of landslide and debris flow is jointly affected by multiple effects.In the analysis of disaster causing factors,the number and density of existing disasters and disaster breeding factors are comprehensively analyzed.Combined with analytic hierarchy process(AHP)and sequence diagram method,it can be seen that the potential landslide inducing areas of Guizhou province are mainly located in the southeastern part of Guizhou province,the northern and western mountainous areas of Guizhou Province.The potential inducing areas of debris flow are mainly west Guizhou and southeast Guizhou.