Hydrological Characteristics and Key Influencing Factors of Typical Lakes in the Qinghai Tibet Plateau from 1985 to 2021

Abstract

[Objective] The lakes of the Tibetan Plateau are important indicators of climate change, and their expansion or contraction also have an important impact on the natural environment of the Tibetan Plateau. [Methods] Three typical lakes located in different climatic sub-regions of the Qinghai-Tibet Plateau (Qinghai Lake, Yangzhuo Yongcuo, and Ulan Ula Lake) were selected to study the temporal and spatial variation of the hydrological characteristics of the three typical lakes from 1985 to 2021 by remote sensing monitoring methods, to reveal the role of key climatic factors, and to further explore the influence of glaciers and permafrost on the typical lakes. [Results] The area and water level of Qinghai Lake showed a significant upward trend, with an area increase of 238.68 km2 and a water level increase of 1.32 m. In space, it showed a trend of expansion in the east-west direction. The area and water level of Yangzhuo Yongcuo Lake first fluctuated and then decreased, decreasing by 16.31 km2 and 3.25 m respectively. In space, the overall area showed a shrinking trend from the surrounding to the center. The area and water level of Ulan Ula Lake showed a significant upward trend, increasing by 125.57 km2 and 8.12 m, respectively, and the expansion area was mainly concentrated in the south. [Conclusion] The analysis of key climate factors shows that the lake expansion caused by the increase of precipitation and the accelerated melting of glacial permafrost in the warm and humid environment is the most prominent environmental change characteristics of the Qinghai-Tibet Plateau. The main reason for the rise in the water level of Ulan Ula Lake is the seasonal thaw of permafrost caused by rising temperatures. Exploring the changes in lake area on the Tibetan Plateau is of great guiding significance for in-depth research on global climate change and surface water resource assessment.

Keywords

• qinghai-tibet plateau
• lakes
• area change
• water level
• glacial permafrost