Changes in permafrost environments along the Qinghai-Tibet engineering corridor induced by anthropogenic activities and climate warming

摘要

The sensitive permafrost environments along the Qinghai-Tibet Engineering Corridor (QTEC) from Golmud to Lhasa are controlled by periglacial processes, geography, geocryology and the local climate. During the past 50 years, permafrost has been degrading at a rapid rate due to the combined influences of steadily increasing human activities and persistent climatic warming, and extensive accelerated degradation has been observed along the QTEC. In many locations, the surface vegetation and the top soils have been completely removed, or destroyed, and have led to significantly increased water and soil erosion, with extensive and serious environmental and engineering impacts. The vegetation along the QTEC is dominated by alpine grasslands and meadows. The alpine grasslands have a better capability for recovery from the damages than the meadows. At sections where the vegetation and soils were severely damaged, it will take 20-30 years for alpine grasslands to recover their ecological structures and biodiversity similar to that of the original conditions, whereas it will take 45-60 years for the alpine meadows. The environmental management and protection along the QTEC are urgent and important for the long-term stability of engineering foundations, and for the sustainable development on the Qinghai-Tibet Plateau (QTP). The proper protection and management requires the development of a non-interference plan and acceleration in the enactment and enforcement of environmental protection (laws, regulations and stipulations) based on an extensive and thorough understanding and practical rehabilitation techniques for disturbed or damaged permafrost environments.