Permafrost Thaw and Associated Settlement Hazard Onset Timing over the Qinghai-Tibet Engineering Corridor

Donglin Guo,Jianqi Sun

doi:10.1007/s13753-015-0072-3

Abstract

In permafrost areas, the timing of thermal surface settlement hazard onset is of great importance for the construction and maintenance of engineering facilities. Future permafrost thaw and the associated thermal settlement hazard onset timing in the Qinghai-Tibet engineering corridor (QTEC) were analyzed using high-resolution soil temperature data from the Community Land Model version 4 in combination with multiple model and scenario soil temperature data from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Compared to the standard frozen ground map for the Tibetan Plateau and ERA-Interim data, a multimodel ensemble reproduces the extent of permafrost and soil temperature change in the QTEC at a 1 m depth from 1986–2005. Soil temperature and active layer thickness increase markedly during 2006–2099 using CMIP5 scenarios. By 2099, the ensemble mean soil temperature at 15 m depth will increase between 1.0 and 3.6 °C in the QTEC. Using crushed-rock revetments can delay the onset of thermal settlement hazard for colder permafrost areas by approximately 17 years in the worst case scenario of RCP8.5. Nearly one-third of the area of the QTEC exhibits settlement hazard as early as 2050, and half of this one-third of the area is traversed by the Qinghai-Tibet highway/railway, a situation that requires more planning and remedial attention. Simulated onsets of thermal settlement hazard correspond well to the observed soil temperature at 15 m depth for seven grid areas in the QETC, which to some extent indicates that these timing estimates are reasonable. This study suggests that climate model-based timing estimation of thermal settlement hazard onset is a valuable method, and that the results are worthy of consideration in engineering design and evaluation.

Highlights

Permafrost regions occupy approximately one-quarter of the land of the Northern Hemisphere and are widely distributed at high latitudes and regions of high altitude (Zhang et al 1999)
This study suggests that climate model-based timing estimation of thermal settlement hazard onset is a valuable method, and that the results are worthy of consideration in engineering design and evaluation
5 of 41 simulated grid cells show disagreement with the map, and these are situated in the warm permafrost region in the southern Qinghai-Tibet engineering corridor (QTEC)

Summary

Introduction

Permafrost regions occupy approximately one-quarter of the land of the Northern Hemisphere and are widely distributed at high latitudes and regions of high altitude (Zhang et al 1999). Changes in permafrost are likely to have a great impact on hydrology and water resources, ecosystem structure, the stability of infrastructure, and climate change (Nelson et al 2002; Yang et al 2010; Guo et al 2011a, b; Koven et al 2011). In addition to the concerns about the climatic, hydrological, and ecological effects of permafrost thaw, there is growing concern with regard to the hazard to human-made infrastructure caused by severe permafrost thaw. This is because permafrost regions tend to contain abundant natural resources, attracting a large number of people and the associated infrastructure development to these regions. Other examples include the development of Prudhoe Bay in central Alaska’s North

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