Abstract:
Due to the impact of global warming, lakes on the Qinghai-Tibet Plateau have begun to gradually expand, posing a threat to the natural environment and field infrastructure. In order to study the impact of climate change on lake water volume, based on CryoSat-2 satellite altimetry data and Landsat remote sensing image data of the 68 Daoban Salt Lake (Salt Lake) in the hinterland of Hoh Xil, Qinghai Province from 2010 to 2018, we extracted the water level and area of the Salt Lake respectively, and combined with the measured underwater topographic data to construct a water level-area-volume relationship curve. Based on the characteristics of climate change, we analyze the driving force of Salt Lake variation. The results showed that: ① from 2010 to 2011, the water volume of the lake increased by 20 million cubic meters, and the Salt Lake was still an independent lake at this stage. After that, the water from the three upstream lakes, Zhuonai Lake, Kusai Lake and Haidingnuoer Lake began to inject into the Salt Lake, then the Salt Lake became the "receiver" of water in the basin, and the water volume began to increase rapidly, rising by nearly 1.2 billion cubic meters in just one year. In 2016, the water volume started to rise at an average rate of about 550 million cubic meters per year. In the past 9 years, the water volume of Salt Lake increased by nearly 3.3 billion cubic meters, and as the "receiver" of water in the basin, Salt Lake continued to expand. ② Increasing rainfall is the main factors for the expansion of the Salt Lake. Melting glaciers and permafrost meltwater caused by increasing temperature may be another climatic factor for lake changes, but not the decisive one.