Institute for Disaster Risk Management, School of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
Institute for Earth Observation, Eurac Research, Viale Druso 1, Bolzano-Bozen 39100, Italy.
Sci Total Environ. 2022 Dec 1;850:158049. doi: 10.1016/j.scitotenv.2022.158049. Epub 2022 Aug 18.
Climate change can alter the frequency and intensity of extreme rainfall across the globe, leading to changes in hazards posed by rainfall-induced landslides. In recent decades, China suffered great human and economic losses due to rainfall-induced landslides. However, how the landslide hazard situation will evolve in the future is still unclear, also because of sparse comprehensive evaluations of potential changes in landslide susceptibility and landslide occurrence frequency under climate change. This study builds upon observed and modelled rainfall data from 24 bias-corrected Coupled Model Intercomparison Project Phase 6 (CMIP6) Global Climate Models (GCMs), a statistical landslide susceptibility model, and empirical rainfall thresholds for landslide initiation, to evaluate changes in landslide susceptibility and landslide occurrence frequency at national-scale. Based on four Shared Socioeconomic Pathways (SSP) scenarios, changes in the rainfall regime are projected and used to evaluate subsequent alterations in landslide susceptibility and in the frequency of rainfall events exceeding empirical rainfall thresholds. In general, the results indicate that the extend of landslide susceptible terrain and the frequency of landslide-triggering rainfall will increase under climate change. Nevertheless, a closer inspection provides a spatially heterogeneous picture on how these landslide occurrence indicators may evolve across China. Until the late 21st century (2080-2099) and depending on the SSP scenarios, the mean annual precipitation is projected to increase by 13.4 % to 28.6 %, inducing an 1.3 % to 2.7 % increase in the modelled areal extent of moderately to very highly susceptible terrain. Different SSP scenarios were associated with an increase in the frequency of landslide-triggering rainfall events by 10.3 % to 19.8 % with respect to historical baseline. Spatially, the southeastern Tibetan Plateau and the Tianshan Mountains in Northwestern Basins are projected to experience the largest increase in landslide susceptibility and frequency of landslide-triggering rainfall, especially under the high emission scenarios. Adaptation and mitigation methods should be prioritized for these future landslide hotspots. This work provides a better understanding of potential impacts of climate change on landslide hazard across China and represents a first step towards national-scale quantitative landslide exposure and risk assessment under climate change.
气候变化会改变全球极端降雨的频率和强度，从而导致降雨诱发滑坡的危害发生变化。近几十年来，中国因降雨诱发的滑坡遭受了巨大的人员和经济损失。然而，未来滑坡灾害情况将如何演变尚不清楚，这也是因为气候变化下滑坡易发性和滑坡发生频率的潜在变化缺乏综合评估。本研究基于观测和模拟的降雨数据，使用 24 个经过偏差校正的耦合模型比较计划第六阶段（CMIP6）全球气候模型（GCM）、统计滑坡易发性模型和经验性的滑坡启动降雨阈值，来评估国家尺度上滑坡易发性和滑坡发生频率的变化。基于四个共享社会经济路径（SSP）情景，预测了降雨模式的变化，并用于评估随后滑坡易发性和超过经验性降雨阈值的降雨事件频率的变化。一般来说，研究结果表明，在气候变化下，滑坡易发生地形的范围和引发滑坡的降雨频率将会增加。然而，更仔细的研究提供了一个关于这些滑坡发生指标如何在中国各地演变的空间异质图景。直到 21 世纪后期（2080-2099 年），并且取决于 SSP 情景，年平均降水量预计将增加 13.4%至 28.6%，导致模拟的中度至高度易发性地形面积增加 1.3%至 2.7%。不同的 SSP 情景与历史基准相比，引发滑坡的降雨事件频率增加了 10.3%至 19.8%。从空间上看，青藏高原东南部和西北盆地的天山山脉预计将经历最大的滑坡易发性和引发滑坡的降雨频率增加，尤其是在高排放情景下。适应和缓解方法应该优先考虑这些未来的滑坡热点地区。这项工作更好地理解了气候变化对中国滑坡灾害的潜在影响，是在气候变化下进行全国尺度定量滑坡暴露和风险评估的第一步。
