Glacier shrinkage in the Ebinur lake basin, Tien Shan, China, during the past 40 years

The Ebinur lake basin, Tien Shan, China, was described in the early 20th century as the 'Green Labyrinth'. This relatively productive area supports agriculture and stands in contrast to the regional aridity. Glacier melt runoff is an important source of water for this arid region and has played a significant role in its economic development. However, over the past 40 years the ecology and environment of the region have seriously degenerated due to human activity and climate change. To investigate changes in glacier water supply, measurements from two reference glaciers were performed and used to validate satellite data and historical data for glaciers in the water catchment. Variability in regional glacier total area and volume over the past 40 years was reconstructed from historical documents, aerial photographs and remote-sensing data. Our investigations of 446 glaciers showed that from 1964 to 2004 the total glacier area decreased by 14.7% (0.4% a(-1)), corresponding to an estimated volume change of 20.5%. During this period, the most dramatic decrease in glacier area corresponded to a rapid rise in temperature. This reduction in glacier area is accelerating and impacting the future sustainability of the region's water resources.