1900-2007年横断山区部分海洋型冰川变化

横断山区7条海洋型冰川近百年进退速度变化呈现出以退缩为总趋势的阶段性变化,具体表现为20世纪初至1930s的冰川稳定,1930s-1960s的冰川后退,1970s-1980s的冰川稳定或减速后退,20世纪80年代中期以来的冰川后退,这与我国、北半球及横断山区同期的气候变化呈明显对应,展现出冷干阶段冰川稳定或前进、暖湿阶段后退的态势,但各冰川的变化幅度因纬度位置、坡向、冰川规模、局地环境等而存在明显差异.1982/83年大、小贡巴冰川、海螺沟冰川冰舌段的消融水当量分别为2710mm、3139 mm和5281 mm,1990/91-97/98期间海螺沟冰川冰舌段的年均消融水当量为6157 mm,比1982/83年增加了876 mm.2002年夏季白水1号冰川的积雪消融量由于表碛覆盖较少表现出明显的随海拔升高而降低的特征,平均消融水当量为1086.25 mm,2008.9-19.10.13期间白水1号冰川物质平衡花竿的观测表明,花竿布设区域10月6号左右转入物质积累期.期间日均积累深为1cm,折合水当量5mm.

Changes of Some Monsoonal Temperate Glaciers in Hengduan Mountains Region during 1900-2007

Since the early 1900s, a tendency for some monsoonal temperate glaciers retreat has been observed in the Hengduan Mountains region. Against the background of climate change, 7 monsoonal temperate glaciers were in a stationary or an advancing state between the 1900s-1930s and the 1960s-1980s, and they were in a retreat state during the 1930s-1960s and from the 1980s to the present, which is consistent with the climatic fluctuations of China, the Northern Hemisphere and Hengduan Mountains region, and these glaciers were steady or advanced when the climate was characterised by cold-dry and vice versa. The variational extent is different among 7 glaciers owing to the locations and scales. The ablation water equivalent of glacier tongue in Dagongba Glacier, Xiaogongba Glacier and Hailuogou Glacier is 2710 mm, 3139 mm and 5281 mm in 1982/83, respectively, and the mean value in Hailuogou Glacier is 6157 mm during 1990/91-97/98, which is 876 mm more than that in 1982/83. The ablation of Baishui Glacier No.1 was in decline with the rise of altitude owing to the less debris cover in the summer of 2002. Based on the mass observation during 2008.9.19-30, the glacier started to accumulate after October 6, and the accumulation depth is 1 cm equal to 5 mm water equivalent per day during 9.30-10.13.