| Resources and environment problems caused by global climate change have drawn widespread attention in the global scope increasingly. As the most sensitive and direct carrier of the information on climate change, glacier is not only an important driving factor of climate change, but also play an important role in the utilization of water resources, sea level rise, glacial disaster prevention and so on. Kuytun River Basin is located in the north slope of the central Tianshan Mountains, the southwest margin of Junggar Basin, which is the main water source of the northern slope of Tianshan economic belt. Due to the Kuytun River is mainly supplied by glacial meltwater and precipitation, so strengthen glacier change monitoring and study is of great significance to the sustainable utilization of water resources, development of social economy, reduction and prevention of natural calamity and so on in the downstream area.Glaciers in Kuytun River Basin of Tianshan Mountains were chosen as research object, based on the GIS and RS technology, the variation characteristics of glaciers were analyzed,using field measured data, topographic data, remote sensing data, meteorological data, etc. The main results are as follows:(1) The total area of the glaciers in Kuytun River Basin reduced by 64.1 km2 from 1964 to 2014. The ratio of reduction was about 31.9%. In addition to the glaciers whose area<0.1 km2, the number and area of the glaciers whose area was 0.1~0.5 km2,0.5~1 km2,1~2 km2,2~5 km2 and 5~10 km2 have reduced all in different degree. The glaciers whose area was 5~10 km2 lost most, area was 1~2 km2 lost least, which indicated that glaciers has shrunk generally in the context of climate warming, and some large glaciers decomposed into medium or smaller glaciers, making the number and area of small glaciers increased.During the investigation of First Glacier Inventory and Second Glacier Inventory of China, the rate of area reduction in different aspect from high to low was NW, SE, SW, W, E, S, N and NE from 1964 to 2009. The number of the glaciers only in the north and northeast aspect was increased, the other aspects were all decreased in different degree, but the glaciers in the South aspect changed slightly. Through the statistics of the glacier terminal elevation, the terminus of glaciers in Kuytun River Basin was mainly distributed in the elevation of 3200~3800 m. With the melting and retreat of glaciers, glacier terminal elevation rose on the whole. The total ice volume of the glaciers in Kuytun River Basin reduced by 4.11 km3 with annual loss of 0.082 km3, and the ratio of loss was about 37.2% from 1964 to 2014.(2) The area of Haxilegen Glacier No. 51 totally reduced by 0.32 km2, the ratio of reduction was 21.6% from 1964 to 2014, showing obviously accelerated melting trend. The average ice-thickness of Haxilegen Glacier No.51 thinned about 10 m with annual reduction of 0.22 m; ice volume decreased by 0.024 km3, the ratio of loss was 14.4% during the years of 1964~2010. From 1964 to 2014, the area of Haxilegen Glacier No. 48 totally reduced by 0.88 km2, the ratio of reduction was 14.4%; ice volume decreased by 0.085 km3, and the ratio of loss was 18.2%. And the fieldwork found that its ice temperature has increased in recent years. By comparison, the ablation rate of Haxilegen Glacier No.51 was higher than Haxilegen Glacier No.48, influenced by type and volume of the glacier under the same background of climate warming.(3) In order to study the relationship between glacier area and perimeter, fractal theory was applied. And based on the stability analysis on spatial structure of the glaciers in Kuytun River Basin, we found that the spatial structure stability of glaciers tended to decline in 50 years, showing that its ablation rate was likely to remain high in future. According to the analysis of meteorological data, the glacial mass loss caused by temperature rise was greater than the recharge from precipitation was the main reason of glacier retreat.(4) Compared with the other monitoring glaciers in Tianshan Mountains, the ablation of Haxilegen Glacier No. 51 was relatively slow. After the analysis found that the causes of regional differences in the variation characteristics of single monitoring glacier was complex. In addition to the affection from regional differences in climate and environment, the volume, type, shape characteristics of glaciers and other factors also have impacts on the ablation. Compared with the related studies in other areas of Tianshan Mountains, we found that Kuytun River Basin belonged to the zone in which the ablation of glaciers was relatively fast, and the rate of area and volume change were both higher than the whole level of Tianshan Mountains.Through the comparison of meteorological data found that the annual average temperature in Kuytun River Basin was relatively high, but the average annual precipitation was relatively less. Therefore the regional difference in climate change was also the main reason for the relative fast ablation of the glaciers in Kuytun River Basin. Besides, its average area of the glaciers was smaller, below the average of Tianshan Mountains, and small and hanging glacier existed numerously also had impacts on it.(5) Affected by rising temperatures, the glacier ablation in the Kuytun River Basin making its glacial meltwater increased by about 0.9×108 m3 during the years of 1987~2009, and its proportion in the annual average runoff rose 13.7%. Therefore, under the background of climate warming, the regulation of glacial meltwater on runoff has been enhanced. |
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