Evaluation Of Eco-environment Quality Based On RS And GIS

"South-to-North Water Transfer"is an important and strategic project in our country. while the West Route Project of South to North Water Transfer can ultimately solves water shortage_for the six provinces in West China, with importance for the Development of the West Regions. In this paper, Yalongjiang River is selected, which is one of the improtant rivers in the West Route Scheme of South to North Water Transfer Project. Then use an integrated model of eco-environment quality to evaluate the Eco-environment quality of Yalongjiang River.Through investigating and collecting datum, five significant indices are abstracted, includeing vegetation coverage degree, altitude, land coverage, annual accumulated temperature and annual rainfall. When selecting the indeces, RS and GIS are made full use, and PCA is used to calculate the weight of every index. Based on these indices, an integrated evaluation model of eco-environment quality is builded. With the model, the study region is evaluated and divided into three grades. the results are :(1)The study region is dominated by second grade, the eco-environment quality is good. The altitude is between 3800m and 4300m; High vegetation coverage is prevailed; Annual accumulated temperature is between 2457 and 3284℃; Annual average rain is dispersed, becoming fewer and fewer form South to North ; Grass and Mesdow is the important land coverage.(2) The horiziontal distribution of the eco-enviroment quality showes evident regional difference, the best is in the south of this region,the second is the middle, the worst is in the north, which has the same changing trend with annual average rain, annual accumulated temperature and vegetation coverage. (3) The vertical difference of eco-enviroment quality is evident, the middle altitude region is dominated, eco-environment quality is good ; the low altitude region is distributed along the Yalongjiang River, eco-environment quality is the best, the high altitude region accounts for less than 10%, eco-environment quality is the worst.The study region―YaLongjiang River, has vast area, hight altiude, dangerous hypsography and inconvenient traffic, therefore, the traditional method for evaluation of Eco-environment quality needs plenty of manpower, materials and money .In this paper, RS is used to get new datum timely, while GIS to do spatial analysis. a qucik and exact method is bulided for evaluating the Eco-environment quality and theoretical foundation for the implement of the West Route Project of South to North Water Transfer .