南水北调雅砻江工程区自然环境评价

在南水北调工程实施前，认清工程区的环境现状，对正确地评价南水北调工程对环境的影响有重要的意义。在RS和GIS支持下，提取海拔高度、植被覆盖、土地利用、年积温和年降水量等5项指标，用于评价研究区的自然环境，评价结果和实际情况基本一致。结果表明:（1）研究区的自然生态环境以二级区为主，自然生态环境质量较好；（2）自然生态环境空间分布有明显的差异，南部最好，中间段次之，北部最差。（3）自然生态环境的垂直分异明显，中海拔为主，环境质量较好；低海拔分布在雅砻江沿岸，环境质量最好；高海拔环境占研究区的20％左右，环境质量最差。

ECO-ENVIRONMENT EVALUATION OF YALONGJIANG RIVER OF SOUTH-TO-NORTH WATER TRANSFER PROJECT

In order to evaluate the impact of South to North Water Transfer Project on environment，it is necessary to understand the existing status of environment before the beginning of the project.Based on RS and GIS technology，five indices，including vegetation index，altitude，land using，accumulated temperature and annual rainfall，were drawn and applied to evaluate natural environment of the research region.The calculation results were in accordance with the existence.The results showed that:（1）the eco environment quality is good in the research region with the second grade region being dominant;(2)the horizontal distribution of the eco environment quality reveals evident regional diversity—the south of the region is the best，the middle is the second，and the north is the worst;(3)the vertical diversity of eco environment quality is evident—the middle altitude region with good eco environment quality is dominant，the low altitude region locating along the Yalongjiang River is the best in eco environment quality，and the high altitude region occupying less than 20% of the research region is the worst in eco environment quality.