Geography

　　Qinghai Lake area is surrounded by Riyue Mount, South of Qinghai Mount, Xiangpi Mount and Datong Mount. The average altitude is 3194m. Gangcha, Haiyan and Gonghe County also belong to this area.

　　About two million years ago, Qinghai Lake was connected with ancient Huang River. 130,000 years ago, the entrance of Qinghai Lake rose due to strong earth movement, which cut the lake and river. From then on, Daotang River was formed and Qinghai Lake became an inland lake. At that period, the climate was quite wet and rainfall was enough. The area of lake was one third larger than nowadays and the depth was 100m higher.

　　10,000 years ago, the local climate began to deteriorate, which resulted in the smaller lake area and more salty water. Islands emerged in the middle of the lake. Nowadays, Qinghai Lake is the largest inland salty lake on highland in China with acreage of 4580 sq.km and perimeter of 360km. The lake can hold 74 billion cubic meters of water in all.