The Qinghai–Tibet Railroad: A milestone project and its environmental impact

After six years construction, the Qinghai–Tibet Railroad (QTR) was completed in 2006 and it has been successfully operational for two years. QTR crosses about 632 km of permafrost regions. A large fraction of the permafrost region is warm, ice-rich permafrost, which makes it much more difficult to construct any infrastructure system on it. Permafrost scientists and engineers have utilized the state-of the-art technology to actively cool the permafrost under the railroad embankment and to ensure stability of railroad embankment. For the first time, a crushed rock layer was used to cool the permafrost under the embankment in such a huge project. This paper provides an overview of these measures used to cool the permafrost and discusses potential long-term problems. Although the Qinghai–Tibet Railroad is referred as a “green” project, potential long-term environmental impacts should not be underestimated.