Abstract: The lakes on the Qinghai-Tibet Plateau are sensitive indicators of global climate change and have a strong feedback effect on global climate change. Due to the breakwater of Zhuonai Lake, the Yanhu Lake of Hoh Xil, located in the hinterland of the Qinghai-Tibet Plateau, is expanding rapidly, which not only harms the surrounding grassland vegetation and the permafrost flowing through, but also interferes with the normal operation of the Qinghai-Tibet railway and the Qinghai-Tibet highway. In this paper, multi-source remote sensing monitoring means are used to monitor the Yanhu Lake in Hoh Xil area in recent 30 years, and the dynamic changes of the area of the Yanhu Lake are extracted from the trend of temporal and spatial changes, and the causes are analyzed. The results show that: ① The collapse of Zhuonai Lake in September 2011 increased the Yanhu Lake of Hoh Xil by 178.535 km² from 1990 to 2020.② Since the completion of the diversion project of Yanhu Lake in Hoh Xil area in 2020, the area of the Yanhu Lake has been effectively contained and will be reduced to 191.145 km² in 2021. ③ The shoreline of the Yanhu Lake has expanded significantly in the southeast and southwest from 1990 to 2020, and the biggest change is that the eastern part of the Yanhu Lake has become an island from the peninsula that once stretched into the center of the lake. ④ The area has a significant correlation with precipitation and temperature, and a weak correlation with sunshine duration and glacial melt water.

Key words: Qinghai-Tibet Plateau, Hoh Xil, Yanhu Lake, water model, lake change, cause analysis