1969～2010年青藏高原北麓河盆地热喀斯特湖塘演化过程

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

青藏高原多年冻土在过去40~50年中经历了显著的退化过程,热喀斯特湖作为冻土退化最直观的表现,其发生和发展直接影响区域水量平衡及生态环境.此外,热喀斯特湖塘在形成过程中还会释放存储于多年冻土层中的碳,影响区域碳循环.因此,青藏高原热喀斯特湖数量和面积演化过程研究对区域水资源、地球化学循环以及气候变化评估具有重要的意义.

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.