| Geological disasters seriously threaten the safety of human life and property and social and economic development.In September 2018 to May 2019,the project based on detailed investigation of geological disasters in Xifeng county of Liaoning province,type,distribution,characteristics of the geological disaster in Xifeng county,etc.A detailed field investigation,based on the geological and geological disasters in the study area the comprehensive analysis of the relevant information,Xifeng county geological disaster of the distribution and forming conditions.Will pick the amount of information method,to determine the coefficient method,and combined with AHP(analytic hierarchy process),and other mathematical method,Xifeng county geological disaster assessment information model,deterministic coefficient model,information model based on AHP,the deterministic coefficient model based on AHP model,combined with the platform of Arc GIS,degree of geological disasters in sexual division and analysis.The main research contents and conclusions are as follows:(1)There are 32 geological disasters in Xifeng county,including 5 landslides,accounting for 15.62% of the total.24 collapses,accounting for 75% of the total;1 debris flow,accounting for 3.13% of the total disaster;Two ground collapses accounted for 6.25 percent of the total.Based on Arc GIS platform,8 evaluation factors such as slope,slope direction,topographic relief,lithology degree of soft and hard,distance from the river,annual precipitation,land use type,distance from the road,etc.were extracted to establish the evaluation system of geological disaster in Xifeng county.Geological disasters mainly occured in low hills,where lithology is hard or semi-hard rock formations,and near rivers and roads,mainly occured in rainy and rainstorm days.(2)Based on Arc GIS platform,8 evaluation factors such as slope,slope direction,topographic relief,lithology degree of soft and hard,distance from the river,annual precipitation,land use type,distance from the road,etc.were extracted to establish the evaluation system of geological disaster in Xifeng county.(2)The geological hazard prone area of Xifeng county is divided into three levels,among which the area of high risk area is 458.26km2,accounting for 17.69% of the total area.There are 9 developed disaster spots in the area,accounting for 28.13% of the total disasters.The disaster spot density is 0.0196.The area of the medium-prone area is 1064.94km2,accounting for 41.12% of the total area.There are 12 disaster spots in the area,accounting for 37.50% of the total disasters.The density of disaster spots is 0.0113.The low-risk area was 1066.78km2,accounting for 41.19% of the total area,and there were 11 disaster spots,accounting for 34.37% of the total disasters.The density of disaster spots was 0.0103.(3)The method of information quantity,the method of certainty coefficient,the method of information quantity based on AHP and the method of certainty coefficient based on AHP were used as the evaluation model respectively,and the spatial analysis function of Arc GIS platform was used to carry out the geological disaster prone zoning in Xifeng county,and the results shows the highly vulnerable areas are distributed in all the towns and townships,mainly in the south of Xifeng county.The highly vulnerable areas are highly consistent with the distribution of rivers and roads.The geological environment in this area is complex,with the ups and downs of the hills on both sides of the mountain.Under the influence of rivers,rainfall and human engineering activities represented by roads,geological disasters are prone to occur.The middle and low vulnerable areas are distributed along the periphery of the high vulnerable areas.The topographic relief in the region is relatively flat,the lithology is relatively hard,the joints and fissures are weak,the weathering degree is weak,or the rocks are not exposed,the vegetation cover is good,and it is relatively far from the rivers and roads. |
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