近50年冈底斯山冰川变化

摘要

Based on the revised First Chinese Glacier Inventory(FCGI),the Second Chinese Glacier Inventory(SCGI)and Landsat OLI images for 2015-2016,we analyzed the spatial-temporal variation characteristics of glaciers in the GangdisêMountains from 1970 to 2016.The results showed that there were 3953 glaciers with a total area of 1306.45 km 2 and ice volume of^58.16 km 3 in the GangdisêMountains in 2015-2016.Glaciers with sizes of 0.1-5 km^2 and<0.5 km^2 accounted for the largest area and the most amounts of glaciers in the GangdisêMountains,respectively.Over the past five decades,the area of glaciers in the GangdisêMountains decreased by 854.05 km^2(-1.09%·a^-1),accounting for 39.53%of the total glacier area in 1970.The increase in temperature during the ablation period was the most important cause for glacier retreat.Compared to other mountains in western China,the GangdisêMountains have experienced the strongest glacial retreat,and the rate of recession has increased in recent years.The decrease of glacier area was mainly concentrated at elevations of 5600-6100 m,and no change in glacier area was observed at elevations above 6500 m.The number and area of glaciers decreased in all orientations in the GangdisêMountains except for south-and southeast-oriented glaciers.Among them,north-oriented glaciers suffered the largest loss of glacier area,while glacier retreat saw the fastest in northwest-oriented glaciers.The rate of glacier retreat increased from west to east in the GangdisêMountains.The relative rate of glacier area change was the highest in the eastern section of the GangdisêMountains(-1.72%·a^-1),followed by the middle section(-1.67%·a^-1)and the western section(-0.83%·a^-1).