四川与长江四川地处长江上游,位于青藏高原东南缘,处于第一级青藏高原和第三级长江中下游平源的过渡带,面积48.5万km2,约占长江上游地区面积的一半。四川省水资源丰富,总量共计约为3489.7亿立方米,以河川径流最为丰富,其中,多年平均天然河川径流量为2547.5亿立方米,占水资源总量的 Sichuan and the Yangtze River Sichuan is located in the upper reaches of the Yangtze River and is located in the southeastern margin of the Qinghai-Tibet Plateau. It is located in the transition zone between the first-level Qinghai-Tibet Plateau and the third-level Pingyuan, the middle and lower reaches of the Yangtze River, with an area of ​​485,000 km2, accounting for about half of the area in the upper reaches of the Yangtze River. Sichuan Province is rich in water resources with a total amount of about 348.97 billion cubic meters and the most abundant river runoff. Among them, the annual average natural river runoff is 254.75 billion cubic meters, accounting for the total amount of water resources