Cryosphere Research Station on the Qinghai-Tibet Plateau, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Cryosphere Research Station on the Qinghai-Tibet Plateau, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China.
Sci Total Environ. 2021 Jul 1;776:145855. doi: 10.1016/j.scitotenv.2021.145855. Epub 2021 Feb 20.
Climate warming could exacerbate the occurrence of thaw settlement hazard in the permafrost regions of the Qinghai-Tibet Plateau (QTP), which would threaten the stability of engineering infrastructure in cold regions. The risk associated with permafrost settlement, valuable for the regional sustainable development, remains poorly assessed or understood on the QTP. In this study, three common Geo-hazard indices were used to assess the settlement risks in the permafrost regions of the QTP, including the settlement index, the risk zonation index, and the allowable bearing capacity index. However, large spatial differences existed in simulating the risk maps by using the abovementioned Geo-hazard indices. Hence, we developed a combined index (I) by integrating the three indices to reduce the uncertainty of the simulations. The results indicated that the ground ice is a critical factor for assessing the settlement risk in permafrost regions. We also applied the I to assess the settlement risk along the Qinghai-Tibet Railway (QTR). The proportion of low-risk area along the QTR would be the highest (45.38%) for the future periods 2061-2080 under Representative Concentration Pathway 4.5. The medium-risk area combined with the high-risk area would be accounted for more than 40%, which were located at the boundary of the present permafrost regions. Therefore, the corresponding adaptation measures should be taken to reduce the potential economic losses caused by the high-risk regions to the infrastructure. Overall, the results would present valuable references for engineering design, construction and maintenance, and provide insights for early warning and prevention of permafrost thaw settlement hazard on the QTP.
气候变暖可能会加剧青藏高原（QTP）多年冻土区融沉灾害的发生，从而威胁到寒区工程基础设施的稳定性。与多年冻土沉降相关的风险对该地区的可持续发展至关重要，但在 QTP 地区，其风险评估或认识仍很不完善。本研究采用三种常见的地质灾害指数来评估青藏高原多年冻土区的沉降风险，包括沉降指数、风险分区指数和容许承载力指数。然而，利用上述地质灾害指数模拟风险图时存在较大的空间差异。因此，我们通过整合这三个指数开发了一个综合指数（I），以降低模拟的不确定性。结果表明，地冰是评估多年冻土区沉降风险的关键因素。我们还应用 I 来评估青藏铁路（QTR）沿线的沉降风险。在代表性浓度路径 4.5 下，未来 2061-2080 年，QTR 沿线低风险区的比例将最高（45.38%）。中风险区和高风险区的总和将占 40%以上，这些地区位于现有多年冻土区的边界。因此，应采取相应的适应措施，以减少高风险地区对基础设施造成的潜在经济损失。总体而言，研究结果将为工程设计、施工和维护提供有价值的参考，并为 QTP 多年冻土融沉灾害的预警和预防提供新的思路。
