近30年各拉丹东冰川变化及对径流的影响

Glacier variations in Geladandong and its impact on the runoff in recent 30 years

冰川作为研究气候变化的因子,冰川变化对揭示地区水文和气候变化至关重要。本研究利用1989—2019年的7景遥感数据和DEM对各拉丹东冰川地貌进行研究,从而探讨在气候变化背景下冰川的变化及对径流的影响。结果表明:(1)1989—2019年有69条冰舌消退,平均消退约236 m,最大消退区位于岗加曲巴,消退距离为3305 m。(2)冰川面积从982.46 km2减少到821.15 km^(2),冰储量从1721.21 km^(3)减少到1213.43 km^(3)。引起冰川消退的主要原因是温度升高。(3)沱沱河流域径流量总体上增加,冰川融水是主要补给形式。本研究认为,各拉丹东地区温度升高导致的冰川消退现象仍在持续,冰川融水增加了流域径流量。

Since glaciers are the factors to study climatic change,the variations of glaciers are important to reveal the regional hydrological and climatic change.Seven remote sensing data and DEM from 1989 to 2019 are used in this study to explore the glacial landforms of Geladandong so as to research the variations of glaciers and its impact on the runoff with climatic change.The results show that:(1)A total of 69 glacier tongues have receded with an average ablation speed of about 236 m from 1989 to 2019.The maximum regression zone is located in Gangjiaquba with a regression distance of 3305 m.(2)The area of the glacier decreased from 982.46 km^(2)to 821.15 km^(2),and the ice volume decreased from 1721.21 km^(3)to 1213.43 km^(3).The receding of glaciers was mainly caused by the increase of temperature.(3)The runoff of the basin of Tuotuo river increased as a whole,and the glacier melt water was the main form of recharge.The results show that the glacier receding caused by temperature rise in Geladandong is still continuing,and the glacier melt water increases the runoff of the basin.