青藏铁路路基表面温度及融冻指数预测  

A Prediction for Temperature and Thawing-Freezing Index of Roadbed along the Qinghai-Tibet Railway

作　　者：江灏[1] 王大勇[1,2] 程国栋[1] 王可丽[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000 [2]中国科学院研究生院,北京100049

出　　处：《冰川冻土》2008年第5期855-859,共5页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(40471005)资助

摘　　要：利用青藏铁路沿线沱沱河和那曲气象站的历史气温资料,采用趋势和波动外推方法预测2010年代两站气温,以此作为青藏铁路路基表面热力学模式的输入,计算输出路基表面辐射温度,然后采用年振幅方法计算2010年代融化指数和冻结指数及融冻比.结果表明:与1990年代相比,2010年代除沱沱河冬季月平均路基表面温度稍有下降外,沱沱河和那曲地区路基表面温度预测值都有较大幅度的上升.其中,沱沱河地区是夏季温度上升较大,升幅达到0.8℃;而那曲地区则是冬季温度上升较大,升幅达到0.6℃.沱沱河夏季路基表面融化指数明显增大,冬季冻结指数略有减小,预测融冻比的升幅在8%以上,达到0.85;融冻比目前仍然保持在1以下,表明其冻结能力依然占优势,但其优势已经在明显减弱,即多年冻土在向退化的方向发展.那曲路基表面融化指数增大而冻结指数减小,使得融冻比大幅度跃升,融冻比的升幅超过10%,达到1.79.总之,与1990年代相比,2010年代沱沱河和那曲地区路基冻土有明显向融化方向发展的趋势.First, the air temperatures in Tuotuohe and Nagqu Stations along the Qinghai-Tibet Railway in the 2010s are predicted by using the extrapolation of tend and wave from the observation data of air temperature. And then, the surface radiation temperatures of the embankment are calculated by using the embankment surface thermodynamic model with the predicted air temperatures as input. On this base, the thawing indexes and freezing indexes in the 2010s are calculated by using the annual amplitude method from the embankment surface temperatures. The research results show that, as compared with those in the 1990s, the embankment surface temperatures at Tuotuohe andNagqu in the 2010s would increase with a greater extent, about 0.8 ℃ at Tuotuohe in summer and over 0.6℃ at Naqu in winter. At Tuotuohe, the thawing index in summer would increase and the freezing index in winter would decrease, and so the thawing-freezing ratio would be 0.85 with an increasing over 8%. Although the thawing-freezing ratio is kept under 1.0 still now, the freezing ability is in the ascendant, but the ascendant begin to fail in, which means the perennial frozen soil is degenerating. In Naqu, the thawing index would increase and the freezing index would decrease, so the thawing-freezing ratio would be 1.79 with an increasing over 10%.

关 键 词：青藏铁路 温度预测 融冻指数预测 

分 类 号：P642.14[天文地球—工程地质学]