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地球科学(中国地质大学学报) 2016
萨吾尔山木斯岛冰川厚度特征及冰储量估算
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Abstract:
冰下地形与冰川体积的估算对冰川水资源研究具有重要意义.以萨吾尔山木斯岛冰川为研究对象,利用Landsat影像数据、探地雷达(ground penetrating radar,简称GPR)冰川厚度数据以及差分GPS数据,分析模拟了萨吾尔山木斯岛冰川横纵剖面的厚度分布特征,采用多种插值方法比较分析,得到木斯岛冰川冰舌区的厚度分布图,初步估算了该冰川的冰储量.结合数字高程模型数据及冰川厚度分布图,绘制了木斯岛冰川冰舌区冰床地形图.研究表明,两个横剖面的冰川槽谷形态存在较大的差异.横剖面B1-B2有典型的“U”型地形发育,冰川厚度可达116.4m;C1-C2横剖面底部地形比较平缓,冰川厚度分布较均匀,平均在70~90m.纵测线A1-A2冰下地形成阶梯状分布,纵剖面冰体平均厚度约为80.89m,最大冰体厚度为122.67m.木斯岛冰川的冰床地形图与该冰川的冰厚度等值线图形成明显对比.在海拔3240m和3280m处存在明显的冰斗地形地貌.初步估算木斯岛冰川冰舌区的平均厚度和冰储量分别为60.5m和0.195km3.与传统计算冰储量的方法相比,利用GPR测量得到的冰川厚度数据来插值计算冰储量的方法,具有更高的准确性.
Ice bedrock topographic map and ice volume estimation play very important parts in glacier melt water research. Muz Taw glacier in Sawir Mountains was explored in this study by means of Landsat remote sensing image, digital elevation model data, ground penetrating radar (GPR) data and GPS positioning data. Its terminus thickness distribution was obtained by analysis and simulation of thickness distribution of its transverse and vertical sections, combined with a variety of interpolation methods, on basis of which the ice volume was estimated. Results show obvious differences between the two transverse profiles. Crosssection B1-B2 has typical “U”type terrain, with maximum glacier thickness of up to 116.4m; crosssection C1-C2 is relatively flat, and glacier thickness distribution is more uniform, with an average of about 70-90m. In longitudinal profile,A1-A2 forms a ladderlike distribution, with an obvious depression in the middle of the ice bed topography. The average ice thickness in longitudinal profile is about 80.89m, with maximum ice thickness of 122.67m. The ice bed topographic map is in sharp contrast with the thickness contour map of the glacier. In addition, there is obvious cirque terrain at an altitude of 3240m and 3280m. The preliminary estimation of the average thickness and total terminus ice volume are approximately 60.5m and 0.195km3, respectively. It is concluded that GPR method has higher accuracy compared with the traditional ice volume estimation method, but it has restrictions because of measurement difficulties