新疆冰川近期变化及其对水资源的影响研究

新疆的冰川水资源居全国第一，在新疆水资源构成和河川径流调节方面占有重要地位。最近30多年来，随着气温升高，冰川出现了剧烈的消融退缩，冰川融水径流量普遍增加，并对气温的依赖性增强。文章基于最新冰川观测研究资料，阐述新疆冰川的近期变化，分析对水资源的影响。研究表明，所研究的1800条冰川，在过去26～44年间，总面积缩小了11.7％，平均每条冰川缩小0.243km2，末端退缩速率5.8m/a。冰川在不同区域的缩小比率为8.8％～34.2％，单条冰川的平均缩小量为0.092～0.415km²，末端平均后退量为 3.5～10.5m/a。由于新疆各流域中冰川的分布、变化特征，以及融水所占河川径流的比例不同，因此，未来气候变化对新疆各个区域水资源的影响程度和表现形式是不同的。分析表明，在塔里木河流域，冰川水资源具有举足轻重的作用，但是，一旦冰川消融殆尽，对该地区将产生灾难性影响，现今该区冰川消融正盛，估计在今后30～50年，只要保持升温，冰川融水量仍会维持。未来20～40年，天山北麓水系中，1km²左右的小冰川趋于消失，大于5km²冰川消融强烈，因此，以小冰川居多的河流受冰川变化的影响较大。东疆盆地水系中的冰川数量少，并处在加速消融状态，河川径流对冰川的依赖性强，冰川的变化已经对水资源量及年内分配产生影响，水资源已经处在不断恶化之中。对于伊犁河与额尔齐斯河流域，未来冰川变化对水资源的影响在数量上可能有限，但会大大削弱冰川融水径流的调节功能。而气候变化对积雪水资源的影响和可能造成的后果应该予以特别关注。

STUDY ON RECENT GLACIER CHANGES AND THEIR IMPACT ON WATER RESOURCES IN XINJIANG, NORTH WESTERN CHINA

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.