1970—2000年青藏高原内流区冰川储量变化的初探

A preliminary study of the volume variation of the glaciers in the Qinghai-Tibetan Plateau Interior Area between 1970and 2000

青藏高原内流区特殊的地理位置和自然环境使得对本区域冰川体积变化的研究相比中国西部其他冰川发育区难度大很多.而作为本区域重要水源补给,同时又是区域气候变化重要指示器的冰川,其储量的变化又是迫切需要获知的信息.在此前提下,本文基于RS、GIS技术平台提取了本区域冰川面积变化数据,并结合冰川目录数据、本区域冰川面积变化的研究资料,采用冰川体积与面积之间的统计关系模型,探讨了本区域冰川自1970年至2000年的体积变化.结果表明在这30年间,区域内冰川体积大约减少了36.25亿m3,相比整个高亚洲区域的冰川退缩速度,本区域冰川的退缩表现的更缓慢.然后,对内流区6个二级流域的冰川体积变化做了详细的对比分析,发现整个内流区冰川体积变化有较大的区域差别:其中5Z3流域冰川体积的退缩率最大,年均退缩率达-11.19%,而变化最小的5Z1流域年均变化率仅为-0.79%.各二级流域在体积变化方面的相同点是,体积退缩率均大于面积退缩率.通过对冰川面积、体积变化特点及其原因的分析,认为气候变化的区域差异是该区域内各二级流域冰川变化存在差异的主要原因.最后根据本文得到的结果,讨论了冰川体积变化对本区域的生态环境造成的影响.

The special geographic position and natural environment make it more difficult to explore the glacial volume variation in Qinghai-Tibetan Plateau Interior Area than in the other glaciated regions. However, glaciers are one of the most important sources of water and one of the key indicators of climate changes, whose volume change information is pressing to know. In this paper, we make a preliminary study on the glacial volume variation from 1970 to 2000 in the Qinghai-Tibetan Plateau Interior Area, applying the statistical model between glacier volume and area and the data of glacier catalogue, existing research output about glacier area change and the extracted glacier variation information based RS and GIS by ourselves. The result shows that glacier volume has lost about 36.25 km3 in the past 30 years since 1970 in the Qinghai-Tibetan Plateau Interior Area, hut it decreases more slowly than the average shrinking of the glaciers in the whole High-Asia. Then we analyze the characteristics of glacial volume change for 6 subcatchments, and it is found that there are some large regional disparities. Among the 6 subcatchments, the 5Z3 area has the largest glacier volume loss, and the percentage of area changes is -11.19%, while the least loss area is 5Zl and its retreat rate is only -0.79% . The similar changes among all the 6 sub-catchments are that the volume shrink rate is greater than the area shrinking rate. The temperature and precipitation are considered to play main role in the change of glaciers for each sub-catchment. Finally, we discuss the ecological environment impact caused by the glacial volume change.