近40a来天山台兰河流域冰川资源变化分析

Glaciers Change in the Tailan River Watershed in the Last 40 Years

台兰河流域作为阿克苏河的支流，是以冰川融水补给为主的河流，流域面积为l324krn2。结合1：5万地形图、LandsatETM＋遥感影像及数字高程模型数据，通过综合计算机自动解译及目视解译的方法，将面向对象图像特征提取方法应用到该流域冰川信息提取中，并以影像叠加数字高程模型来提取表碛覆盖区的冰川末端边界，最后参照专家指导意见进行边界的再次修订，得到1972～2011年该流域的冰川变化数据，并分析了过去近40a来冰川变化特征及其对气候变化的响应过程。结果表明：1972～2011年，台兰河流域冰川退缩明显，冰川总面积从435．44km。退缩到385．38krn。，减少了50．06km。，退缩率为11．50％，年均减少约1．25km2，平均单条冰川面积减小0．31km。；冰川总条数从113条减少到109条，消失冰川10条，有3条冰川分离成了9条，其余100条冰川都呈减小趋势。结合阿克苏和拜城气象站气象资料分析认为，台兰河流域冰川萎缩与该地区气温快速上升关系密切，气温上升导致的冰川消融在一定程度上抵消了降水增加对冰川的补给。

The Tailan River Watershed, a branch of the Aksu River Basin, is a glacier-melt runoff river and has a drainage area of 1 324 km2. So far, there is still no detailed assessment of changes of the characteristics of the glaciers. Therefore, timely and correct assessment of glacier changes in the Tailan River to fill gaps in this re- gion is urgent, and it has an extremely important significance for the Tailan River Watershed＇s economic devel- opment and people＇s livelihood. 1 ： 50 000 topographic map data, Landsat ETM＋ remote sensing images and digital elevation model data were used in this research. Through integrated computer automatic interpretation and visual interpretation methods, the object-oriented image feature extraction method is applied to extract gla- cier information. And the images overlying digital elevation model was used to extract the debris- covered gla- cier terminal in this region. At last, the expert guidance was referenced to revise the glacier outline again. Gla- cier change data in 1972-2011 were derived from this research, and analyses the glacier variation characteris- tics and its response to climate change in the past nearly 40 a. The results show that： between 1972 and 2011, the Tailan River watershed rs glaciers had an evident retreat trend, the total area of glaciers was from 435.44 km2 to 385.38 km2; shrinking at a rate of 11.50%, with the average annual decrease was approximately 1.25 km2 and the average single glacier area decrease was 0.31 km2. Glacier total number decreased from 113 to 109, 10 glaciers were disappeared and three glaciers separated into nine remaining. Other 100 glaciers were presenting decreasing trend. In 2011, according to the results of object-oriented image feature extraction meth- od of glacier distribution and temporal variation, glaciers in this basin are mainly distributed in an elevation of 3 900-4 200 m range, and aspect of the glacier terminal toward the east occupy the vast majority in this basin. By analyzing Aksu and Baicheng weather stations＇ annual average temperature and precipitation data from 1960 to 2010, the mean annual temperature increased significantly and the annual precipitation also showed an increasing trend. The study concluded that glacier shrinkage is closely related with temperature rising and gla- cier melting caused by rising temperatures offsets the supply by increased precipitation to some extent.