STUDY ON RECENT GLACIER CHANGES AND THEIR IMPACT ON WATER RESOURCES IN XINJIANG, NORTH WESTERN CHINA
新疆冰川近期变化及其对水资源的影响研究

Xinjiang,the Uyger Autonomous Region in North Western China,possesses the biggest ice volume of the glaciers in China,which plays an extremely important role both on water resource and stabilization of river runoff in this vast arid and semi-arid region.During the past several decades,due to climate warming,the most glaciers in Xinjiang are in a state of rapid retreating.Therefore,the impact of the glacier recession on water resource has drawn a wide attention.Based on field observation and remote sensing data,this study has revealed the variations of 1800 glaciers during the past four decades and analyzed the potential influence of the glacier variations on the water resource in Xinjiang.As a result,the total area of the investigated glaciers has reduced 11.7%.The average area of individual glaciers has reduced by 0.243km~2,and the average retreat rate of that is 5.8m/a.The glacier area reductions in different drainage areas range between 8.8%～34.2% for the total area,and 0.092～0.415km~2 for the individual glacier.The potential impact of the glacier recession on water resource in future is spatially different.For the Tarim River,the glacier runoff is estimated to maintain its current level in next 30～50 years if the air temperature continually increases.Because the glacial runoff accounts for a large amount of the river's runoff,at the beginning,the increasing in glacier melt would enrich the river runoff.However,once the ice volume reduced to a certain value,a shortage of water resource in Tarim River Basin is inevitable.In the north slop of Tianshan,the glaciers with a size smaller than 1 km~2 are most likely to be melted away in next 20～40 years,and tht～se larger than 5km~2 are melting intensively.The impact of which on different river basins in this region would be different depending on the proportion of glacial runoff to the river runoff.In Eastern Xinjiang,because the number of the glaciers is small and also because the climate is extremely dry,the glacier retreating are causing the water shortage problem.For Ili River and Irtysh River,because the river runoff are dominant by snow melt runoff,the impact of the glacier shrinkage and temperature rise would be limited with respect to the quantity of the river runoff,but significant on the annual distribution of the river runoff.The snow melt is important for these two river systems and needed to be particularly study.