甘肃积石山M_(S)6.2地震地质灾害发育特征及孕灾环境分析  

Characteristics of geological hazard development and disaster-inducing environment of the M_(S)6.2 earthquake in Jishishan,Gansu Province

作　　者：陆诗铭 吴中海[1,2] 黄婷 LU Shiming;WU Zhonghai;HUANG Ting(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China;School of Earth and Space Sciences,Peking University,Beijing 100081,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部活动构造与地质安全重点实验室,北京100081 [3]北京大学地球与空间科学学院,北京100081

出　　处：《地质力学学报》2025年第1期139-155,共17页Journal of Geomechanics

基　　金：中国地质调查项目(DD20230002);国家自然科学基金云南联合基金项目(U2002211);西藏自治区第1次全国自然灾害综合风险普查项目(2022年地震灾害部分)(XZLX-BMC-2022-053)。

摘　　要：2023年12月18日甘肃省临夏州积石山县发生M_(S)6.2地震,此次地震诱发了崩塌、滑坡和泥流等一系列地质次生灾害,是近年来中国6级以上地震损失极其严重的一次。综合分析区域孕灾环境及地质次生灾害发育特征发现,拉脊山地区海拔高、地形复杂、活断裂作用显著以及第四纪松散堆积物覆盖广且厚度大等因素,使得该地区在地震作用下极易产生蠕滑-拉裂破坏并诱发滑坡等地质次生灾害。利用层次分析法综合考虑断裂、地层岩性、植被覆盖、坡度及降水5个关键因子对积石山区域地质灾害发育的影响。研究结果显示,地层岩性是区域地质次生灾害的主导因素,其权重可达42%;其次是断层,权重约占26%;而降水的影响权重虽然只占6%,但也不可忽视。积石山及其邻区地质次生灾害危险区主要集中在震中周围的拉脊山前缘一带,呈条状分布,与Ⅷ度地震烈度区域大体一致。地质次生灾害点受软弱地质环境影响为主,集中在拉脊山断裂带下盘,尤其是积石山县、大家河镇和白藏镇等地,灾害分布密集且受地震影响显著,需要重点监测及预防,同时对第四系黄土层防护工程也应予以足够重视。另一方面,在余震分布密集区,未发现显著的地质次生灾害点,推测是因为主震释放了较大应力,诱发了主要地质次生灾害。在多次余震之后,岩体应力状态逐渐趋于平衡,地质构造在震后重组并趋向稳定,从而降低了进一步发生地质次生灾害的风险。[Objective]The M_(S)6.2 earthquake that struck Jishishan County,Gansu Province,on December 18,2023,triggered a series of secondary geological disasters,including landslides,collapses,and debris flows.This earthquake is considered one of the most devastating seismic events in China in recent years.The study aims to analyze the characteristics of seismicity-induced disasters in the region and identify the underlying geological factors contributing to these secondary geological hazards.Specifically,the research focuses on how the geological environment influences the development of these disasters,particularly landslides,collapses,and debris flows.This understanding will help to develop better disaster prevention and mitigation strategies for similar seismic regions.[Methods]To investigate these issues,the study uses a combination of field investigations,remote sensing image interpretation,and the analytic hierarchy process(AHP).The AHP was employed to evaluate the relative importance of five key factors—faults,lithology,vegetation cover,slope,and precipitation—in the formation of secondary geological hazards.The analysis also includes a detailed spatial distribution study of these factors and how they interact under seismic conditions.This multi-method approach provides a comprehensive understanding of the complex geological environment in Jishishan.[Results]Based on the integrated analysis,the secondary geological hazard zones of the study area are primarily concentrated along the front edge of Lajishan,closely aligned with the VIII seismic intensity zone of the Jishishan M_(S)6.2 earthquake.Fewer hazard zones are located at the northern edge of Lijia Village,Guantan Village,and Manisigou Township.The higher-risk areas are centered around Jishishan County,extending eastward toward Lijia Village and Hanji Town.The secondary geological disaster points are concentrated in Jishishan County and the area surrounding it,particularly in valleys where Quaternary strata are abundant,forming a band-like distribution.Land

关 键 词：积石山地震 孕灾环境 滑坡 泥流 空间分析 

分 类 号：P546[天文地球—构造地质学]