The consecutive lake group water storage variations and their dynamic response to climate change in the central Tibetan Plateau

Abstract

Lakes on the Tibetan Plateau (TP) are a reliable indicator of local and global climate changes. Surveying lake water storage (LWS) and understanding the causes of lake variations are crucial to regulate water resources and protect local ecology. However, the lake bathymetric survey and the analysis of consecutive lake changes were absent on the TP. In this study, we investigated the LWS for seven lakes in the central TP and estimated their water storage variations during the period of 1976–2018 by utilizing long-term time series Landsat images and bathymetric data. Then, the driving factors of lake water storage variations were also analyzed based on the data of the meteorological station. The results suggested that the LWS of the seven lakes (Co Nag, Daru Co, Dung Co, Pung Co, Co Ngoin, Bam Co, and Neri Punco) in the central TP expanded by 2.54 km3 (22.12%) from 1976 to 2018, with total lake area increased by 183.42 km2 (22.73%), especially experienced obviously increasing trend between 1997 and 2006. The growth of LWS between 1997 and 2006 explained 70.63% of the net increase during the whole period. While the correlation analysis of LWS and climate change revealed that temperature, precipitation, and evaporation all had impacts on the changes of LWS, temperature and precipitation dominated the main role for the expansion of these lakes during the period of 1997–2006, and LWS had approximately 3 years of lag time in response to precipitation. We also found that the time of the abrupt increase of LWS was probably associated with the step change point of annual precipitation.