Effects of coastal erosion on landslide activity revealed by multi‐sensor observations
Effects of coastal erosion on landslide activity revealed by multi‐sensor observations
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DOI：
10.1002/esp.4880
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发表时间：
2020-06
影响因子：
3.3
通讯作者：
I. Doi;S. Matsuura;Hikaru Osawa;T. Shibasaki;S. Tosa
中科院分区：
文献类型：
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作者：
I. Doi;S. Matsuura;Hikaru Osawa;T. Shibasaki;S. Tosa
海岸侵蚀正成为气候变化的一个日益严重的后果。本研究在考虑海岸侵蚀量与孔隙水压力变化之同时，探讨海岸侵蚀对山崩活动之影响。为了确定与滑坡产生相关的因素，我们专门测量了日本东北部北海道沿海滑坡7个月的位移、变形、孔隙水压力和高时间分辨率（1 s-1 h）侵蚀量。已确定滑坡与高孔隙水压力同时发生。坡脚侵蚀事件也发生了几次，而滑坡表现出重大位移。由于脚趾侵蚀和孔隙水压力的增加同时发生，我们试图通过进行稳定性分析，结合这两个因素的影响，以确定这两个主要贡献的滑坡位移。从实际观测数据来看，坡脚侵蚀和孔隙水压力的增加对所研究滑坡的失稳具有可比性。具体而言，时间序列的安全系数表明，在坡脚侵蚀的情况下，滑坡失稳比在没有侵蚀的情况下，在安全系数的差异超过5%。考虑坡脚侵蚀的滑坡模型对滑坡位移有较好的解释。此外，倾斜数据表明，侵蚀发生至少1个月前的滑坡位移。这意味着海岸侵蚀在海岸滑坡的准备和持续位移中发挥了作用。由于河流下切或人工建筑物的下切作用，内陆滑坡的坡脚具有与所研究的滑坡相似的地貌环境。这里获得的知识可以有助于了解与此类滑坡有关的失稳机制和地形变化。© 2020约翰威利父子有限公司
Coastal erosion is becoming an increasingly serious consequence of climate change. This study demonstrates the effects of coastal erosion on landslide activity while considering the amount of erosion and changes in pore water pressure. To determine the factors related to landslide slip generation, we specifically measured the displacement, deformation, pore water pressure, and amount of erosion with high temporal resolution (1 s–1 h) for a coastal landslide in Hokkaido, north‐eastern Japan, for 7 months. It has been determined that landslides occur simultaneously with high pore water pressure. Toe erosion events also occurred several times, while the landslide exhibited major displacement. Because toe erosion and the increase in pore water pressure occurred simultaneously, we tried to determine which of the two contributed majorly to the landslide displacement by conducting a stability analysis that incorporates the effects of the two factors. From the actual observed data, toe erosion and the increase in pore water pressure had comparable effects on the destabilization of the studied landslide. Specifically, the time series for the safety factor shows that the landslide in the case with toe erosion was destabilized more than that in the case with no erosion, with a difference of more than 5% in the safety factor. The model with toe erosion provided a better explanation for the landslide displacement. Furthermore, the inclination data suggested that erosion took place at least 1 month before the landslide displacement. This implied that coastal erosion played a role in the preparation and ongoing displacement of the coastal landslide. Inland landslides with toes that are subject to undercutting due to river incision or artificial construction have geomorphological settings that are similar to those of the studied landslide. The knowledge obtained here can contribute to the understanding of destabilization mechanisms and terrain changes related to such landslides. © 2020 John Wiley & Sons, Ltd.