Abstract:
Based on the field investigation of the Luding
MS6.8 earthquake occurred on September 5, 2022, combined with the remote sensing interpretation, the development characteristics and controlling factors of coseismic geohazards triggered by the Luding earthquake are summarized, and the evolution trend of coseismic geohazards is studied and judged. According to the different phases of prevention and mitigation of coseismic geohazards, corresponding suggestions are given in order to benefit the prevention and control of geohazards. The results show that the coseismic geohazards of the Luding earthquake are mainly small-medium-sized collapses and landslides, which are concentratedly distributed in three areas: Moxi town and Hailuogou valley, Wandong village of Detuo town and both banks of Daduhe river in Detuo town. Mainshock and aftershocks, Xianshuihe active fault, topography, special rock and sediment mass are the main controlling factors for spatial distribution of coseismic landslides triggered by the Luding earthquake. The geohazards after Luding earthquake will be extremely active in the next 10 years. It is necessary to pay close attention to the high-locality and steep slopes on both banks of the Moxihe river and its tributaries, the Daduhe river, the high-locality terrace along the Daduhe river, the edge area around the Moxi platform, and the debris flows in Moxi town and Detuo town where coseismic landslides are densely developed. Therefore, according to the management logic of emergency prevention of coseismic geohazards, it is suggested that local governments should follow the three phases of detailed investigation, restoration and reconstruction, and long-term planning to carry out geohazard prevention and mitigation work.