Fuxian Lake, whose water is crystal clear and crystal clear, was called "Liuli Wanqing" by the ancients. It is located between Chengjiang City, Jiangchuan District and Huaning County of Yuxi City, and its Hubei end is 52 kilometers away from Kunming. It is an important leisure, tourism and holiday destination in the whole province. Fuxian Lake is the largest water storage lake, the largest plateau deep water lake and the second deep fresh water lake in China. It belongs to Nanpanjiang River system. The lake level is gourd-shaped in the north-south direction, and the runoff area of the basin is 1053km (including Xingyun Lake 378 km). When the elevation of Fuxian Lake is 1722.5 m, the water area is about 216.6 km ², the lake length is about 31.4 km, and the widest part of the lake is about 11.8 km; The total length of the lake shoreline is about 100.8 km, the maximum water depth is about 158.9 m, the average water depth is about 95.2 m, the corresponding lake capacity is about 20.62 billion m, and the water quality is Class I. There are 52 rivers entering the lake, such as Liangwang River, Dongda River and Maliao River, and 53 intermittent rivers and agricultural irrigation ditches, with an average annual runoff of 167.23 million m, and the only outlet of Haikou River is about 95.72 million m. After the completion of Fuxian Lake-Xingyun Lake outflow diversion project, the highest water level of Fuxian Lake is 1722.00 m and the lowest water level is 1720.50 m; Fuxian Lake delivers water to Xingyun Lake from February to May every year. The two lakes operate independently in the rest of the year and discharge to Haikou River in case of major floods. The vegetation in Fuxian Lake Basin is mainly secondary vegetation such as grass, shrub and coniferous forest, with a forest coverage rate of 27.03%. The qualified area for afforestation in the basin is about 164,000 mu, the area for returning farmland to forest is about 96,000 mu, and the area for controlling soil erosion is about 96.2 km ². The existing soil erosion area in runoff area is 208.8 km ², accounting for 30.94% of the total area, and the annual amount of sediment lost into the lake reaches 345,600 tons. The water storage capacity is equivalent to 15 Dianchi Lake and 6 Erhai Lake, accounting for 68.8% of the total water storage capacity of the nine plateau lakes in Yunnan. The beauty of Fuxian Lake cannot be separated from the clear water of Fuxian Lake. As early as the late Ming Dynasty, traveler Xu Xiake wrote in his Travels of Xu Xiake that "Yunnan Mountain is only rich in soil, so it flows into the sea, while the flow is turbid, but Fuxian Lake is the clearest".