Permafrost Thaw and Associated Settlement Hazard Onset Timing over the Qinghai-Tibet Engineering Corridor
Permafrost Thaw and Associated Settlement Hazard Onset Timing over the Qinghai-Tibet Engineering Corridor
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DOI：
10.1007/s13753-015-0072-3
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发表时间：
2015-12
影响因子：
4
通讯作者：
Donglin Guo;Jianqi Sun
中科院分区：
文献类型：
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作者：
Donglin Guo;Jianqi Sun
在多年冻土区，地表热沉降灾害发生的时间对工程设施的建设和维护具有重要意义。利用来自共同体陆地模型版本4的高分辨率土壤温度数据，结合耦合模式比对项目(CMIP5)第五阶段的多个模式和情景土壤温度数据，分析了青藏工程走廊(QTEC)未来的冻土融化和相关的热沉降灾害发生时间。与青藏高原标准冻土图和ERA中期数据相比，多模式集合再现了1986-2005年青藏高原1米深度的多年冻土和土壤温度变化的程度。在2006-2099年间，使用CMIP5情景，土壤温度和活动层厚度显著增加。到2099年，QTEC 15米深的总体平均土壤温度将增加1.0至3.6摄氏度。在RCP8.5的最坏情况下，使用碎石护岸可以将较冷的永久冻土区的热沉降灾害的发生推迟约1700年。早在2050年，青藏高原近三分之一的地区就出现了沉降风险，而这三分之一的地区有一半被青藏公路/铁路穿越，这种情况需要更多的规划和补救措施。模拟的热沉降场与QETC中7个网格区15m深度的地温观测结果吻合较好，这在一定程度上说明了时间估算的合理性。研究表明，基于气候模型的热沉陷灾害发生时间估计方法是一种有价值的方法，其结果值得在工程设计和评估中参考。
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.