| Abstract Analysis of dynamic change of desertification is the foundation of desertification control.Based on the multi temporal TM image data in recent years of study areas,by the interpretation of the images,using RS & GIS soft,desertification grade distribution maps of different periods have been obtained.Dynamic change process of desertification was discussed in terms of desertification area change,spatial changes of desertification grades.The results show an obvious downward trend of total desertification area since 1989.In view of the spatial variations of desertification grades,the desertification is controlled in most areas along the main course of Yellow River,but the desertification area is increased in southeastern,southern desert hinterland,as well as the surrounding of lakes.In addition to general engineering,biological measures,the irrational human activities should be eliminated in order to maintenan dynamic balance of ecological systems and human environment. |
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2010, Vol. 8 