Study On The Geographical Units Classification Research Of Rocky Desertification Evaluation In Karst Mountain Area Based On Multi-source Data

Rocky desertification is not only influence human survival environment,caused a series of natural disasters,and restricted economic development in the region.Over the years,as the rocky desertification in southwest areas,some experts and scholars had made a large study,and had achieved a large number of research results about Rocky desertification evaluation and comprehensive treatment.In terms of rocky desertification evaluation unit,The present study is limited to administrative region and grid,to better evaluate rocky desertification,paper main line is divide the Rocky desertification evaluation geographic unit,study on the rocky desertification is more serious in southwest GuanLing County,to use the "3S" technology mainstream,Analytic hierarchy process(AHP),the methods of comparative analysis,object-oriented classification method and so on.Extract the high precision land use data use the Object-oriented classification method on karst mountainous area.Based on multi-factor coupling relation space clustering analysis technology;Comprehensive analysis they relationship: the land use data,the lithology data,the rainfall data and gradient data,divide the Rocky desertification evaluation geographical unit.The main research contents and results are as follows:(1)Based on the high resolution remote sensing image,use the Object-oriented classification method,extract the high precision land use data,by analyzing field validation,the classification accuracy reached 86.69%.(2)Using the analytic hierarchy process(AHP),build the corresponding hierarchy model for each relevant units,through the judgment matrix to analyze the relations between the two factors,and judge the feasibility of the model.Giving the various factors different weights in each category,based on multi-factor coupling relationship the spatial clustering analysis technology.(3)Dividing the rocky desertification evaluation geographical units into Relevant units and related units in the study area,the relevant units be further divided based on land use and score range.Based on the land use,the unit is classified into forest land cell division,cell division,the grass dry cell division,garden land zoning districts and bare land units;based on the score range,the unit is classified into Level 1 to 5 five levels.(4)Evaluating the rocky desertification evaluation based on the geographical unit,the study area is divided into no obvious rocky desertification,potential rocky desertification,mild rocky desertification,moderate rocky desertification and intensity rocky desertification.The evaluation results show: GuanLing County rocky desertification degree mainly mild rocky desertification and moderate rocky desertification,wide distribution and mainly distributed in the west of GuanLing County.