A PANORAMA OF LANDSLIDES TRIGGERED BY THE 8 AUGUST 2017 JIUZHAIGOU,SICHUAN MS7.0 EARTHQUAKE |
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| Authors: | XU Chong WANG Shi-yuan XU Xi-wei ZHANG He TIAN Ying-ying MA Si-yuan FANG Li-hua LU Ren-qi CHEN Li-chun TAN Xi-bin |
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| Affiliation: | 1. Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China;2. Sichuan Earthquake Agency, Sichuan Chengdu 610041, China;3. Hebei Earthquake Agency, Hebei Shijiazhuang 050021, China;4. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China |
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| Abstract: | The MS7.0 Jiuzhaigou earthquake in Sichuan Province of 8 August 2017 triggered a large number of landslides. A comprehensive and objective panorama of these landslides is of great significance for understanding the mechanism, intensity, spatial pattern and law of these coseismic landslides, recovery and reconstruction of earthquake affected area, as well as prevention and mitigation of landslide hazard. In this paper, we use the trinity method of space, sky and earth to create a panorama of the landslides triggered by this event. There are 4 roads in the distribution area of the coseismic landslides. The Jinglinghai-Xiamo and Jiudaoguai-Jiuzhaitiantang road sections register the most serious coseismic landslides. The landslides are mainly of moderate-and small-scales, and also with a few large landslides and avalanches. A detailed visual interpretation of the coseismic landslides is performed in two areas of Wuhuahai(11.84km2) and Zharusi-Shangsizhai village(47.07km2), respectively. The results show the overall intensity of landsliding(1088 landslides, a total area 1.514km2) in the Wuhuahai area is much higher than those in the Zharusi-Shangsizhai village area(528 landslides, a total area 0.415km2). On the basis of a scene of post-earthquake Geoeye -1 satellite images, we delineate more than 4 800 coseismic landslides with a total occupation area 9.6km2. The spatial pattern of these landslides is well related with the locations of the inferred seismogenic fault and aftershocks. Widely distributed earthquake-affected weakened slopes, residual loose materials staying at high-position slopes and in valleys have greater possibilities to fail again and generate new landslides or debris flows under the conditions of strong aftershocks or heavy rainfalls in the future. Geological hazard from these events will become one of the most serious problems in the recovery and reconstruction of the earthquake-affected area which should receive much attention. |
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| Keywords: | Jiuzhaigou MS7.0 earthquake landslide trinity of space remote sensing visual interpretation seismogenic fault |
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