Heterogeneity of glacial lake expansion and its contrasting signals with climate change in Tarim Basin, Central Asia

Abstract

On the basis of Landsat TM/ETM +/OLI imagery in the years 1990, 2000 and 2013, changes of lake area were detected and its contrasting signals with climate change are addressed for Tarim Basin in Central Asia. During the past 23 years, the lake area has expanded at an average rate of 0.67 %/a, with the fastest rates in Altun Shan and Tian Shan mountains and slower rates in the Karakoram and Pamir, which indicates spatially heterogeneous warmer and wetter climatic signals in the basin. Examining decades, the average expansion rate of lake area (0.98 %/a) over 2000–2013 was about four times that (0.23 %/a) of 1990–2000, indicating accelerated warmer–wetter trends around the transition year 2000 in the mountain areas. Discrepant area expansion of different types of glacial lake implies contrasting signals of climate change in the Tarim Basin. Fewer direct climatic signals can be inferred from changes of supraglacial lakes. Ice-contacting lakes characterized by the fastest expansion rate (3.35 %/a) depict accelerated glacier shrinkage caused by climate warming. Non-glacier-fed lakes expansion at the rate of 0.57 %/a reflect an apparent increase of precipitation in the mountains of Tarim Basin.