摘要
以西藏南部外流水系冰川系统结构为基础 ,应用冰川消融与夏季气温的关系、冰川径流变化规律、平衡线的代表性特征及其上升的降温效应 ,提出冰川系统变化的功能模型 .结果表明 :在持续升温的情景下 ,海洋型冰川对径流变化响应迅速 ,且退缩快、寿命短 ,而增流率不大 ,增流期短 ,在本世纪内径流将全面衰减 ;大陆型冰川对径流变化响应迟钝 ,且退缩慢、寿命长 ,而增流率大 ,增流期长 ,下世纪以后径流才将衰退 ;规模大及高差大的冰川比规模小及高差小的冰川退缩慢 ,寿命长 ,而增流率大 。
In the basins of the Ganges, Yarlung Zangbo and Indus there are 19 575 km 2 of glaciers, accounting for one-third of the total glacier area in China. On the basis of the structure of the glacier system and the nature of the equilibrium line altitudes at the steady state, functional model of the variation of glacier system are established, using Kotlyakov-Krenke's equation relating annual ablation of glacier and mean summer temperature. The models are applied to the study of the response of glacial runoff to climatic change. The effect of decreasing air temperature due to rising of %ELA% and reduction of glacier area is considered in these model simultaneously. The modeling results under the climatic scenarios with temperature increasing rates of 0^01, 0^03 and 0^05 K·a -1 indicate that the glacial runoff fed by the marine-type glaciers with high levels of mass balance are very sensitive to climate change, it will take 10～30 years to reach a climax, and go back to their initial state in less than 100 years. However, the increasing rate of glacial runoff is small. During a peak period, the discharge-increasing rate will range from 1^01 to 1^14. In contrast, the glacial runoff of the continental-type glaciers, characterized by lower level of mass balance smaller decreasing rate of glacier size, and longer life-span responds climate variation slowly; it will take over 100 years to a climax and hundreds of years to return to their initial state. During a peak period, the discharge-increasing rate will ranged between 1^6～4^0 for extrexly continental-type glaciers. The decreasing rate of size for the marine type glaciers has larger than the continental-type on in case of 0^05 K·a+{-1} and in 100 a, the former one is {-0.82} and the later one is {-1.8}. At the similar levels of mass balance, smaller glaciers respond quickly to the climate change and also retreat relatively fast. The glacier system with very large elevation difference have the longest life span. The life span of the Rongbuk Glacier on the n
出处
《冰川冻土》
CSCD
北大核心
2002年第1期16-27,共12页
Journal of Glaciology and Geocryology
基金
国家重点基础研究发展规划项目 (G19980 40 80 0 )
中国科学院知识创新工程重大项目 (KZCX2 30 1)
中国科学院天山冰川观测试验站基金 ( 990 1)资助
