Integrated assessment and changes of ecological environment in the Daning River Watershed

Based on Remote Sensing (RS),Geographical Information Systems (GIS),and the Spatial Principal Component Analysis (SPCA) method,the integrated assessment and changes in the ecological environment of Daning River Watershed are studied in this paper.The watershed is located in the Three Gorge Area in China.The result of the integrated assessment showed that level 9 had the biggest proportion in the year 1990,which was about 40%.In the year 2000,however,there were no levels with a proportion significantly bigger than the others.By comparing the assessment results in 1990 and 2000,it is discovered that the ecological environment in Daning River Watershed in 1990 was better than that in 2000.