关键词: 荒漠化, 人文因子

Abstract: This thesis takes four typical areas as examples to study the function of human factors in desertification process by means of qualitative and quantitative methods on the basis of other experts study.The four typical areas are Xijingzi,Naritu,baiyintala and Jiangjia Ravine.By means of the comparative analysis of desertification criteria and quantitative study of recent desertification process,it is found that the influences of human factors on desertification have the comprehensive,dominant and special functions.In the historical desertification process,desertification was mainly controllde by natural factors,especially by climate change.The dry climate made environment change into desert,and the unstable society and economy resulted from the ecological environment change caused environmental degradation and led to the appearance of large area of shifting dunes.In recent times,the cause of desertification is that human activities extremely intensified the natural environmental degradation process on the basis of natural evolution due to increasingly dry climate.The area and degree of desertification is enlarged or extended with the increase of population and livestock pressure.Therefore,recent desertification is known as man-made process.But,there is also natural process at present,for example,Naritu.All in all,it is found that the function of human factors occupies 60.0% while the natural factors accounts for 40% based on the principal components analysis.The speed difference between natural and man-made desertificaiton process is big,the development speed of man-made desertification process is about ten times as big as that of natural process.