昆仑山北坡冰川湖变化及其溃决风险评估

Changes in glacial lakes on the northern slope of Kunlun Mountains and assessment of their outburst risks

探究昆仑山北坡冰川湖时空变化及冰川湖溃决洪水(Glacier lake outburst flood,GLOF)风险评估对区域水资源安全和生态发展具有重要意义。基于Google Earth Engine(GEE)遥感计算平台分析昆仑山北坡冰川湖近30 a的变化特征和GLOF风险评估模型对当前的冰碛湖进行灾害与风险评估。结果表明:(1)1990—2023年昆仑山北坡冰川湖呈显著增长趋势,冰川湖的数量从1990年的248个增加到2023年的925个(增加了2.73倍),面积从1990年的14.99 km^(2)增加到2023年的54.83 km^(2)(增加了2.66倍),冰川湖在昆仑山北坡西部高海拔山区增加显著。(2)通过对2023年GLOF风险评估分析得出,灾害水平在叶尔羌河流域最高(约占47.2%),其次是和田河流域(约占15.7%)。风险水平较高是叶尔羌河流域(约占50.8%),叶尔羌河流域高风险冰川湖占整个昆仑山北坡高风险冰川湖的60.7%。(3)1990—2023年冰川湖的增长趋势与区域气候变化相关,山区降水增加和冰川积雪消融是冰川湖扩张的主要原因。开展冰川湖溃决洪水风险评估可为干旱区水资源可持续利用,为下游地区防灾预警提供科学依据和支撑。

The exploration of spatiotemporal changes in glacial lakes on the northern slope of Kunlun Mountains and the risk assessment of glacier lake outburst floods(GLOF)are of great significance for regional water resource security and ecological development.Using the Google Earth Engine(GEE)remote sensing platform,this study analyzed changes in glacial lakes on the northern slope of Kunlun Mountains over the past 30 years and applied a GLOF risk assessment model to evaluate current moraine lakes for disaster risk.The results indicate the following:(1)From 1990 to 2023,the number and area of glacial lakes on the northern slope of Kunlun Mountains increased significantly.By 2023,the number of glacial lakes had risen to 925,marking a 2.73-fold increase from 248 in 1990.Similarly,the area of glacial lakes expanded to 54.83 km^(2),a 2.66-fold increase from 14.99 km^(2) in 1990.This growth was particularly notable in the high-altitude mountainous regions of the western part of the northern slope.(2)The 2023 GLOF risk assessment indicates that the Yarkant River Basin poses the highest disaster risk,accounting for approximately 47.2%of the assessed area,followed by the Hotan River Basin at 15.7%.In terms of risk levels,the Yarkant River Basin shows a relatively high-risk,accounting for about 50.8%,and high-risk glacial lakes in the Yarkant River Basin glacial lakes account for 60.7%of the high-risk glacial lakes on the entire northern slope of the Kunlun Mountains.(3)The increasing trend in glacial lakes from 1990 to 2023 is closely related to regional climate change.Rising temperatures have led to increased precipitation in mountainous areas and accelerated the melting of glaciers and snow,which are the primary drivers of glacial lake expansion.The GLOF risk assessment contributes to the sustainable management of water resources in arid regions and provides a scientific basis for disaster prevention and early warning systems in downstream areas.