Study On Soil Salinization In The Western Plain Of Jilin Province Based On GIS

After taking part in many projects about Jilin west plain, the author discovered that soil salinization is leading problem of eco-geo-environment in Jilin west plain, and vast salinized land resource is not availably exploited. So the soil salinization has been chose as research direction of the doctor's degree thesis. Soil salinization was studied in the eco-geo-environmental system by technical means of GIS and RS coupling mathematical model.The process of soil salinization in Jilin west plain is a synthetical result that irrational human activity overlaps on vulnerable eco-geo-environment. The vulnerable eco-geo-environment established the base of soil salinization; the irrational human activity triggered off and accelerated the process.By way of providing scientific basis for comprehensive development of salinized land resource and quantificational forecasting the soil salinization, the author brings forward the new concept of "risk level of soil salinization", and appraises the risk level of soil salinization in Jilin west plain quantificationally.Making a comprehensive view of soil salinization study at home and abroad, the formers mostly analyzed single factor of soil salinization with qualitative method. Traditional study methods can't fulfil the need of quantificational appraising the risk level of soil salinization, so the advanced methods must be introduced into the study of soil salinization. It is an innovative attempt that soil salinization is studied by technical means of GIS and RS coupling mathematical model. RS afforded the spacial distribution and types of soil salinization; the spaceorientation and quantification of the factors of eco-geo-environment were completed by GIS. The quantificational relation of the eco-geo-environmental factors and the soil salinization were obtained by the spatial analysis function of GIS. After GIS coupling with mathematical models, the dominating contributory factors were ascertained by Grey Relating Model: the training samples were picked by Fuzzy Clustering Model: the risk level of soil salinization were appraised by ANN Model. The appraised result indicated that the background of eco-geo-environment in Jilin west plain is very fragile, the risk level of soil salinization is very high. The land that can't salt-alkalize merely account for 22.12% of Jilin west plain, they mainly distribute on foothill-highland and top of sand dunes. The land that salt-alkalize very easily is as high as 53.97% of the total area, they distribute in the central section of Jilin west plain, Da'an, Qian'an, Zhenlai county with low-lying surface relief and high groundwater elevation. The land with secondary risk level takes up 23.92% of the total area, they distribute in Fuyu, Taonan and Qianguo county.