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1、念青唐古拉峰地区冰川变化及其对气候变化的响应-RS与GIS的应用摘要：念青唐古拉峰（念峰）地区现代冰川较为集中，冰川类型复杂，伴随着全球变暖，该地区冰川退缩幅度较大。我们选取该区域现代冰川作为研究对象，通过地形图数据、卫星遥感数据、野外实测数据，借助GIS对研究区的冰川37年来在冰川规模参数、地形参数和类型参数的变化进行了详细分析。高分辨率光学遥感影像ASTER为获取念峰地区2007年的冰川特征参数提供了较好的数据源，同时，ASTER同轨立体像对为研究该地区长时间段内冰面高程的变化信息提供了条件。念峰地区冰川从我国第一次系统的冰川调查起到目前已经发生了较大的变化，迫切需要进行冰川各项参数的更新
2、以及冰川变化的详细研究。GIS为进行冰川各项参数的快速提取以及冰川各项属性信息的集成分析提供了技术基础。通过1970地形图数据与2007年ASTER遥感影像数据对念峰地区现代冰川详细的参数化分析，我们获取了以下几点认识：念峰地区现代冰川自1970年到2007年37年的时间里，冰川数量增加，冰川面积却减少了121.93 km2，总的面积退缩率为17.6%。冰川个体规模进一步缩小，冰川平均面积降到了1.0 km2以下。小冰川数目增加迅速，预示着该地区即使在未来气温维持不变的情景下，也将会出现更大的冰川退缩速率。对选取的面积为315.61 km2冰川体积遥感监测表明，19702007年37年的时间段
3、内，冰川厚度有明显的减薄趋势。冰川面积 0.5 km2 的冰川，其相对面积损失比率较大，超过28%。小冰川相对面积损失比率明显高于较大冰川，证明研究区面积 0.5 km2小冰川对于气候变化极为敏感。同时，面积 20%），面积的相对缩减变化总体上来说要快于冰川长度的退缩。研究区平均气温在过去近37年里呈现上升趋势，特别是念峰北部地区。该地区降水变化较小。区域气温升高是该地区整体冰川退缩的主要原因。另外，根据念峰地区主山脊西北坡和东南坡的冰川变化差异与气温和降水的变化差异对比，同时，考虑到该地区冰川朝向对于冰川变化的巨大影响作用，认为该地区局地地形因子对于西北坡和东南坡冰川变化的差异性起着决定性的
4、作用。Abstract：Modern glaciers are well developed in the Mt.Nyainqntanglha region with diverse glacier types. Under the background of global warming, glaciers have been shrinking in the region. A detailed study was then carried out to understand the glacier changes based on various parameters of glacie
5、r, such as dimension, topography and typology, combining the satellite data, topographic data and field survey data with GIS technology in the last 37 years.The ASTER satellite images which are high-resolution optical remote sensing data facilitate accessing the detailed glacier parameters. In addit
6、ion, the along-track stereo pairs of ASTER can provide a new DEM which enable the glacier surface elevation in 2007 compare with the old topographic data (1970) during the last 37 years. Glaciers in the Mt Nyainqntanglha region have been changed greatly since the first systematic glacier survey by C
7、GI. There is an urgent need to update the glacier parameters and conduct a detailed glacier change research. GIS makes the rapid automatic extraction of glacier parameters and an integrated analysis of glacier property information possible. With the parametric analysis on topographic data of 1970 an
8、d ASTER data in 2007, we obtain a well understanding of glacier changes in the Mt.Nyainqntanglha region.The main results of the glacier change analysis are:(1) The relative loss in glacier area from 1970 to 2007 is about -17.6% in the Mt.Nyainqntanglha region. The glaciers increase in the number, wh
9、ile decreasing by 121.93 km2 in the glacier area. The average glacier area is smaller than 1.0 km2. The smaller glaciers lost proportionally more area than the larger glaciers. Glaciers smaller than 1 km2 contribute about 32% to the total loss although they cover only 23.7% of the area. There is an
10、even higher relative area loss ratio for the glaciers smaller than 0.5 km2 which is over 28%. With the growing number of small glaciers, a greater retreating rate of glaciers in the area can be expected even if the climate condition remains unchanged in the coming future. A selected spatial domain w
11、ith glacier area of 315.61 km2 shows a notable wastedown tendency. The average annual rate of volume loss is 0.16 km3a-1.(2) No significant correlations were found between magnitude of glacier shrinkage and topographic characteristics of glacier median elevation, slope or minimum elevation. However,
12、 there is a notable shift in glacier ice area to glacier aspect. The largest relative area loss ratio happened in the glaciers with W aspect which is more than 25% and followed by NE aspect. Glaciers with NW aspect show the weakest retreating rate. The glacier length change has a similar retreat ten
13、dency with glacier area when the relative area loss is below 20%.（3）Mean temperature increases over the past 37 years with little change in precipitation in the Mt.Nyainqntanglha region. Regional warming is the main reason for the overall glacier retreat. The glacier change has a relative difference
14、 with temperature and precipitation changes on both sides of Mt.Nyainqntanglha region. In addition, the glacier aspect has a great influence on its change. Taking these two factors into account, we draw a conclusion that the local topographic parameters play a crutial role in the glacier change differences on the north-west and south-east slopes.
念青唐古拉峰地区冰川变化及其对气候变化的响应-RS与GIS
