萨吾尔山冰川现状及演化过程

Glaciers in Saur Mountains:Current situation and evolutionary process

萨吾尔山是中国西部14座冰川分布的山系之一,横跨中国和哈萨克斯坦两国,尽管冰川规模不大,但因二元政治主体割裂了科学研究的完整性,同时萨吾尔山冰川水资源对于新疆阿勒泰地区吉木乃县可持续发展具有重要意义,为此结合航摄地形图、Landsat及Sentinel卫星遥感影像,并参考已有冰川编目和Google Earth高分辨率历史图像等数据资料,在野外台站现场观测验证基础上对萨吾尔山冰川当前现状和过去30多年间的变化进行了详细研究。结果表明:(1)截止2022年,萨吾尔山共分布冰川31条,总面积11.47 km^(2),新疆吉木乃县境内的木斯岛冰川为最大规模冰川,面积2.95 km^(2),其余90%的冰川其面积不足1 km^(2)。(2)过去30多年来,萨吾尔山冰川变化的总体趋势是冰川分裂、面积减小和末端后退持续增加。冰川数量从12条分裂成31条,1989-2022年冰川面积减少8.11 km^(2),退缩率达41.42%,冰川末端退缩11.30 m。气温升高、冰川反照率降低和冰川破碎程度加大是引起萨吾尔山冰川退缩的主要原因。(3)相较于我国其他13座高大山系,萨吾尔山在过去半个多世纪中冰川面积相对退缩幅度最大。未来在全球气候变暖背景下萨吾尔山冰川极大可能会基本消融殆尽,这对本就干旱贫水的吉木乃县可持续发展将产生重要影响,需提早统筹谋划以应对未来的水资源危机。

The Saur Mountains,one of the 14 mountain ranges with glaciers in western China,span across China and Kazakhstan.Although the glaciers are relatively small,scientific research is challenged by the division between two political entities.The water resources from the Saur Mountains’glaciers are crucial for the development of Jeminay County,Xinjiang,China.This study integrates aerial topographic maps,Landsat and Sentinel satellite remote sensing images,existing glacier inventories,Google Earth high-resolution historical images,and other data.Remote sensing observations were verified on-site,and a detailed study on the current status and historical evolution of the Saur Mountains’glaciers over the past 30 years was conducted.The results indicate that:(1)As of 2022,there are 31 glaciers in the Saur Mountains,covering a total area of 11.47 km^(2).The Muz Taw glacier,the largest in the range,is located in Jeminay County with an area of 2.95 km^(2).The remaining 90%of glaciers are each less than 1 km^(2),but collectively account for 54.55%of the total glacier area.The latitude height and lower altitude limit of glacier distribution in the Saur Mountains are second only to those in the Altay Mountains,making the Saur Mountains a typical high-latitude,low-altitude glacier distribution region in China.(2)Over the past 30 years,the glaciers in the Saur Mountains have experienced increased splitting,area shrinkage,and terminal retreat.The number of glaciers increased from 12 to 31,while the total glacier area decreased by 8.11 km^(2),a retreat rate of 41.42%.During the same period,the length of each glacier retreated by 373 m,with an average annual retreat of 11.30 m.Rising temperatures,reduced glacier albedo,and increased glacier fragmentation are the primary reasons for this retreat.(3)Compared to the other 13 mountain ranges in western China,the Saur Mountains have experienced the largest relative retreat in glacier area over the past half-century.With global warming,the glaciers in the Saur Mountains are likely to completely melt,significantly impacting the sustainable development of Jeminay County,which is already dry and water-poor.Early planning is essential to address the impending water resource crisis in Jeminay County.