Research On Assessment Of Landslide Vulnerability Based On Remote Sensing And Extension Theory

The central mountain of Sri Lanka is located in the south-central part of the country.The climate is affected by the southwest monsoon and northeast monsoon.The precipitation is rich,the complex geological features and high-intensity rainfall and other factors have caused frequent landslides,debris flows and other geological disasters,and people ’s lives and property losses huge.Identifying and carrying out the assessment of the susceptibility of landslide disasters in the region through scientific methods is of great significance for disaster prevention and mitigation and land planning.In view of the above,in view of the problems that the existing landslide susceptibility evaluation model in the past cannot fully meet the actual situation,combined with remote sensing technology to identify landslides in the study area,the study area landslide types are divided into two types of soil and rock landslides.Based on the analysis of the formation conditions of landslide development,the extension comprehensive evaluation model method was tried to be used in landslide susceptibility evaluation and prediction to construct an evaluation system.The applicability of the model and the accuracy of the evaluation were discussed.The main research results are as follows:(1)Based on the analysis of the geological mechanism of landslide formation,by using satellite remote sensing technology and man-machine interactive interpretation method,the historical landslide disasters in the study area were extracted,and the main spatial distribution and development rules of landslide disasters were mastered.A total of 754 landslides are distributed in the study area.Among them,soil landslides occupy the majority,with a total of 493,and the remaining 261 are rock landslides.The development of landslides is largely controlled by factors such as rainfall,topography and landform.(2)Based on the study of landslide disaster in the area of remote sensing interpretation results and the analysis of the spatial development law,from the material conditions,the space condition,structure condition and induced condition,selection of stratigraphic lithology,geological structure,elevation,slope,the surface fluctuation degree,the strength of runoff,profile curvature,slope direction and rainfall,a total of nine factors,this paper establish a landslide liability evaluation index system,use fuzzy analytic hierarchy process(FAHP)and entropy value method combining subjective and objective weight method to determine index weight,and comprehensively reflect the subjective intention of objective information to decision-makers.(3)The extension comprehensive evaluation method is used to effectively evaluate and predict the landslide vulnerability in the study area.According to the landslide susceptibility,the whole area is divided into five levels: high susceptibility,higher susceptibility,medium susceptibility,lower susceptibility and low susceptibility,and the final vulnerability zone map is obtained based on GIS analysis.(4)The prediction accuracy of the extension comprehensive evaluation model is tested by using the ROC comparison test and the overall prediction accuracy test method.the results of the two kinds of inspection methods integrated display landslide liability prediction results are basically consistent with the actual development situation,indicating that the extension comprehensive evaluation method has certain suitability and high prediction accuracy in the evaluation of landslide susceptibility in the study area.