高亚洲冰川区SRTM C-波段DEM数据透射深度研究

Study of penetration depth for the SRTM C-band DEM in the glacier area over the High Mountain Asia

SRTM数据是研究冰量变化的重要数据之一。基于SRTM C-波段和X-波段的高程数据,对高亚洲不同冰川区SRTM C-波段数据的透射深度进行了研究。结果表明:高亚洲地区SRTMC透射深度的空间分布特征存在较大差异,其中藏色岗日地区的透射深度最大为(5.3±2.1)m,中天山和念青唐古拉西段地区的透射深度最小仅为(0.8±0.6)m。透射深度整体空间分布呈由高亚洲边缘地区向青藏高原内陆先减小后增大,到羌塘高原地区SRTMC的透射深度最大的趋势。气温和降水量的空间差异共同作用是导致SRTMC透射深度呈上述分布状况的主要因素。此外,SRTM X-波段数据的覆盖状况和冰川样本数量的选择会导致不同研究估算出的SRTMC透射深度存在不确定性。

The Shuttle Radar Topography Mission（ SRTM） DEM is the most valuable resources to evaluate glacier volume change. The penetration depth of SRTM C-band digital elevation model（ DEM） in different glacial regions over the High Mountain Asia（ HMA） was calculated and compared with the SRTM X-band DEM. The results showed that the spatial patterns of SRTMC DEMs were various,with the maximum penetration depth of（ 5. 3 ± 2. 1） m in the Zangser Kangri and the minimum depth of（ 0. 8 ± 0. 6） m in the central Tianshan Mountains and western Nyainqentanglha Range. The spatial distribution of penetration depth gradually decreases and then increases from the marginal areas of HMA to the inner Tibetan Plateau with a maximum in Qiangtang Plateau. It is mainly due to the difference in spatial patterns of temperature and precipitation. Additionally,the coverage condition of SRTM X-band and the sampling number of glaciers might cause the uncertainties of penetration depth calculation in different study areas.