甘肃积石山Ms 6.2地震次生地质灾害分布规律与发育特征

Distribution patterns and development characteristics of secondary geological hazards caused by the Ms 6.2 earthquake in Jishishan,Gansu

地震是诱发山区地质灾害最主要的原因之一.受发震构造、岩体强度、地貌形态等的综合影响,地震诱发的次生地质灾害通常具有显著的分布规律和发育特征,揭示该规律对抗震救灾和风险评估具有极为重要的支撑作用.2023年12月18日23:59,甘肃省积石山保安族东乡族撒拉族自治县发生Ms 6.2级地震,在甘肃省和青海省造成严重的人员伤亡和财产损失,地震导致部分在册地质灾害隐患点危害加剧,同时诱发大量新生地质灾害,以崩塌、滑坡、泥石流为主要类型.震后,通过快速的遥感解译和实地调查,获取了此次地震次生地质灾害隐患数据集,结果显示地震导致新生崩塌灾害多于滑坡,而诱发滑坡数量相对较少,加剧泥石流的数量不多;空间特征表现为受逆冲构造“上下盘效应”和软弱黄土地质环境的显著控制;地貌条件,尤其是坡度、坡向和相对高差显著影响同震灾害的空间分布.

Earthquakes are one of the main causes of geological disasters in mountainous areas.Due to the comprehensive influence of seismic structures,rock mass strength,and geomorphic morphology,secondary geological disasters induced by earthquakes usually have significant distribution patterns and development characteristics.Revealing this pattern is extremely important for earthquake relief and risk assessment.On December 18,2023,at 23:59,an Ms 6.2 magnitude earthquake occurred in Jishishan County,Gansu Province,causing serious casualties and property damage in both Gansu and Qinghai Provinces.This earthquake has intensified some registered geological hazards and triggered a large number of new geological hazards,mainly including collapse,landslides,and mudslides.After the earthquake,the team obtained a dataset of secondary geological hazards caused by the earthquake through rapid remote sensing interpretation and on-site investigation.The results showed that the earthquake caused more new collapse disasters than landslides,and the number of induced landslides was relatively small,with only a few exacerbating mudslides.The spatial characteristics are significantly controlled by the upper and lower wall effects of thrust structures and the weak loess geological environment.The geomorphic conditions,especially slope,aspect,and relative height difference,significantly affect the spatial distribution of coseismic disasters.