| Landslide is the most frequent type of geological disaster in China,which has the characteristics of concealment,suddenness and strong destructiveness.It causes serious harm to the construction of transportation,urban construction,water conservancy and hydropower projects and the safety of human life and property.It is of great significance for the prevention and mitigation of landslide geological disasters and the development of local society and economy to study the susceptibility of landslide disaster in key areas.Based on digital elevation model(DEM),Landsat 8 remote sensing(RS)images and1:200000 geological map,Arc GIS platform was used to extract nine evaluation factors which are closely related to landslide such as the elevation,slope,aspect,topographic relief,land-use types,normalized difference vegetation index,roads,river system and faults,taking Xunwu County,Jiangxi Province for example.Combined with the landslide geological disaster data in the study area,the analytic hierarchy process(AHP)and the weighted information model are used to calculate the weight of each factor and construct the evaluation index system,so as to conduct the partition and evaluation of landslide disaster susceptibility in Xunwu area.The main contents and conclusions of the study are as follows:(1)The AHP and the weighted information model are used to evaluate the landslide susceptibility of study area.The results showed that four grades were divided:high susceptibility area,medium susceptibility,low susceptibility and non-susceptibility area.The zoning results from AHP method showed that the high susceptibility area of landslide disaster is 291.29 km~2,accounting for 12.39%of the total area of the county.The landslide disaster prone area is 524.74 km~2,accounting for 22.32%.The low susceptibility area of landslide disaster is 837.19 km~2,accounting for 35.61%.The non-susceptibility area of landslide disaster is 697.31 km~2,accounting for 29.66%.The zoning results based on the weighted information model showed that the landslide disaster prone area is 552.72 km~2,accounting for 23.51%of the total area of the county.The prone area of landslide disaster is 259.08 km~2,accounting for 11.02%.The low susceptibility area of landslide disaster is752.79 km~2,accounting for 32.02%.The none susceptibility area of landslide disaster is786.41 km~2,accounting for 33.45%.The results of the two evaluation methods are basically consistent with the zoning of the geological disaster prevention plan of Ganzhou.The distribution of landslide geological disasters and the key ranges of prevention and control in Xunwu County were identified and clarified.(2)The characteristics of landslide distribution and the causes of landslide analysis study area showed that landslides are mainly distributed in elevation of 200?600 m,slope of 10?30°,aspect of 202.5?247.5°,337.5?360°and 0?22.5°,relief of 0?40 m area.These areas are prone to landslides due to the development of faults and frequent huam activities.Based on the analysis of the regions of landslide susceptibility,it was found that the high susceptibility areas are mainly concentrated in the faults,roads,water systems and their surrounding areas.The controlling degree of the induced factors to the occurrence of landslide in the study area is relatively high.(3)The rationality test results of the vulnerability zonations obtained by the AHP and the weighted information model showed that two methods are consistent with the test that the number of landslides,proportion and disaster density of landslides decrease with the lower vulnerability.The landslides were concentrated in the areas of high vulnerability and moderate vulnerability and the evaluation results were relatively reliable.The evaluation results showed that the area of the highly vulnerable areas was too large due to the difference of information quantity and the disaster density from…method was lower than that of the AHP method.Hence,the evaluation accuracy of the AHP is more reasonable in the study area. |
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