000032435 001__ 32435
000032435 041__ $$aEnglish
000032435 100__ $$aWu, Q.
000032435 245__ $$aThermal Impacts of Engineering Activities and Vegetation Layer on Permafrost in Different Alpine Ecosystems of the Qinghai–Tibet Plateau, China
000032435 260__ $$c2016
000032435 300__ $$a1695-1706
000032435 520__ $$aClimate warming and engineering activities have various impacts on the thermal regime of permafrost in alpine ecosystems of the Qinghai–Tibet Plateau. Using recent observations of permafrost thermal regimes along the Qinghai–Tibet highway and railway, the changes of such regimes beneath embankments constructed in alpine meadows and steppes are studied. The results show that alpine meadows on the Qinghai–Tibet Plateau can have a controlling role among engineering construction effects on permafrost beneath embankments. As before railway construction, the artificial permafrost table (APT) beneath embankments is not only affected by climate change and engineering activities but is also controlled by alpine ecosystems. However, the change rate of APT is not dependent on ecosystem type, which is predominantly affected by climate change and engineering activities. Instead, the rate is mainly related to cooling effects of railway ballast and heat absorption effects of asphalt pavement. No large difference between alpine and steppe can be identified regarding the variation of soil temperature beneath embankments, but this difference is readily identified in the variation of mean annual soil temperature with depth. The vegetation layer in alpine meadows has an insulation role among engineering activity effects on permafrost beneath embankments, but this insulation gradually disappears because the layer decays and compresses over time. On the whole, this layer is advantageous for alleviating permafrost temperature rise in the short term, but its effect gradually weakens in the long term.
000032435 700__ $$aZhang, Z.
000032435 700__ $$aGao, S.
000032435 700__ $$aMa, W.
000032435 773__ $$pThe Cryosphere
000032435 773__ $$v10 (4)
000032435 773__ $$a10.5194/tc-10-1695-2016
000032435 8564_ $$uhttp://www.the-cryosphere.net/10/1695/2016/$$yExternal link (open access)
000032435 980__ $$aARTICLE