Thermokarst lake changes between 1969 and 2010 in the Beilu River Basin, Qinghai-Tibet Plateau, China

This work presents changes of thermokarst lakes from Beilu River Basin on the Qinghai-Tibet Plateau over the past four decades (1969-2010) using aerial and satellite image interpretation. The results indicated that thermokarst lake activity had generally increased rapidly between 1969 and 2010. The number of thermokarst lakes had increased by approximately 534, and their coverage expanded by about 410 ha. The two main changes observed were an increase in the number of small lakes and the expansion of larger lakes. These changes are likely the result of persistent climate warming and a gradually increasing imbalance between precipitation and evapotranspiration (P-ET). However, some non-climatic factors, such as the lake-bottom substrate and local engineering activities, have also influenced the lake changes. If air temperature and P-ET continue to rise, the number of thermokarst lakes and the area they cover may continue to increase in the future.