Expansion of Glacial Lakes and Its Implication for Climate Changes in the Chinese Himalaya

The Himalayas has drawn a wide attention in the context of the changing climate.The expansion of glacial lakes shows the variation of climate changes and is of importance to understand the risks of glacial lake outburst flood.On the basis of large scale topographical maps,DEMs,ASTER,images,glacial lake area variation against elevation and the changes of distance between glacial lake and its parent glacier were analyzed and the climatic implications were discussed in the Chinese Himalaya.The results show that,in the past 30 years,(1) the survived glacial lake expansion was a dominant contributor to the increase of glacial lake area,accounting for about 67%,and new formed lakes contributed to the rest 33% of area increment;(2) glacial lake area was averagely increasing in all 100-m-elevation bands where the largest growth occurred at elevations of 5000-5300 m,indicating a vertical variety of climate changes;(3) the more closer the glacial lake is to its parent glacier,the greater the area increasing rate of the glacial lakes,and among 15 types of glacial lake-glacier distance variation,60% of net lake area increment was due to the lakes directly connected with parent glaciers in the 2000s in Chinese Himalaya.