1988-2013年布加岗日地区冰川变化及其对气候变化的响应

基于Landsat TM/ETM+/OLI遥感影像，采用比值阈值和目视解译相结合的方法提取分析了唐古拉山东段布加岗日地区近25 a来冰川现状及其变化，对比研究了四个时段的冰川变化特征及其对气候变化的响应。结果表明:1988—2013年研究区冰川退缩比较严重，面积退缩34.25 km²，占1988年冰川面积的18.67%，且不同时段冰川退缩速率不同，1988—1994—1999—2006—2013年冰川退缩表现为:慢—最快—中等—快的特点，冰储量预测减少15.38%。夏季气温升高很可能是造成冰川加速退缩的主因，冰川变化对气候变化的响应更好地体现在长时段的气候变化上，而短时段气候变化对冰川总体变化趋势有一定的作用，这是造成各个时段冰川变化差异性的原因。研究区北坡冰川退缩明显快于南坡，这种变化的差异性一方面可能是由研究区季风气候特征和水汽来源对不同朝向冰川的影响造成的，另一方面也受冰川发育规模、分布海拔的影响。

Variation of Glacier and Its Response to Climate Change in the Bujiagangri Region From 1988 to 2013

We used the ratio threshold and visual interpretation to extract and analyze the glacier change and variation in the Bujiagangri region in the last 25 years based on Landsat data (TM/ETM+/OLI). Comparedto the variations of glacier in the four periods and its response to climate change, the result demonstrated that the glacial retreat was serious from 1988 to 2013 where 34.25 km² (18.67%) of glacier area had been retreated. In addition, the rates of glacier decline in 1988—1994—1999—2006—2013 appeared to be slowest, fastest, medium, and then faster, respectively. Generally, the volume of the glacier was decreased by 15.38% at the end of year 2013. The increase of temperature in the summer was likely to be the main reason for this phenomenon. Moreover, glacial change response was significant in the long-term climate change, while the short-term climate change was significant only in the overall trend of the glacier change. Generally, glaciers in the northern area declined quickly than that of the southern area due to the monsoon climate variations, the water vapor sources differences and variations in the scale and the elevation of the glacier areas.