中国-巴基斯坦喀喇昆仑公路Ghulkin冰川百年进退变化

巴基斯坦喀喇昆仑山的Ghulkin冰川是距离中国-巴基斯坦喀喇昆仑公路最近的典型冰川之一,其冰川的进退变化影响着喀喇昆仑公路改建工程的线路设计与工程施工.为了追溯Ghulkin冰川的活动历史和查明近期进退变化,对过去200 a的相关文献和记录进行统计分析,并开展了2008-2011年野外定点观测,总结与分析了Ghulkin冰川冰舌的活动历史与近期变化.研究表明：Ghulkin冰川在1885-1980年近百年间经历了3次前进和3次后退,在此期间冰川波动了625 m;1913-1925年冰川处于显著的前进状态,1966-1978年冰川有小段距离的前进;2008-2011年K676+660处泥石流沟道逐年抬升,2011年南坡冰川融水由K676+660改道至K676+450;2010年的南坡冰舌较1994年后退了300余米,2011年的南坡冰舌较2010年后退了15.066 m,可见在2010-2011年期间冰川处于局部短期后退状态. 中巴公路冰川泥石流等灾害不但受区域气候的影响,而且还受冰川变化的影响.未来气候变暖将会导致冰川的强烈消融和后退,冰川融水携带大量冰碛体,形成大型的冰川泥石流,对公路的安全运营造成严重威胁.

Advance and Retreat Fluctuation of the Ghulkin Glacier Along the Karakoram Highway over Hundred Years

The Ghulkin Glacier is one of the most typical active glaciers, which threats the Karakoram Highway (KKH) with its nearest snout position variation. The glacier fluctuation significantly influences the design and construction of the Improvement Project of KKH. In order to trace the movement history of the Ghulkin Glacier and understand its recent behavior, in this paper, literatures dated as old as from the past two hundred years were analyzed and then a consecutive three year field surveys had been made from 2008 to 2011. Distances from the south and north glacier tongues of the Ghulkin Glacier to the left bank of Hunza River in the period of 1885-1994 were sketched in this paper. The field survey of the snout position was made and compared with history records. It is found that the snout position had fluctuated by 625 m during the period of 1885-1980, with three retreats and three advances, respectively, and a notable advance from 1913 to 1925 and a small advance from 1966 to 1978; The debris flow gouge of K676+660 rises year after year and the channel of meltwater of south glacier tongue has changed from K676+660 to K676+450 since 2011; The south glacier tongue in 2010 retreated approximately 3 hundred meters as compared with that in 1994, and it retreated approximately 15 meters from 2010 to 2011. This research fills in the data gap of glacier along KKH in the latest thirty years. Glacial debris flow along KKH not only affected by regional climate, but also affected by glacier variation. Climate warming will lead to intense melting and retreat of glaciers, melting water mixing with moraine will induce large-scale glacial debris flow which poses a serious threat to KKH.