中川乡地震前后土壤含水指数变化与泥流灾害关系的探讨  

Discussion on the relationship between soil moisture index changes before and after the Zhongchuan Township earthquake and mud flow disasters

作　　者：石轩 许长军 杨阳 侯光良 SHI Xuan;XU Changjun;YANG Yang;HOU Guangliang(School of Geography,Qinghai Normal University,Xining 810016,China;Qinghai Province Key Laboratory of Physical Geography and Environmental Process,College of Geographical Science,Qinghai Normal University,Xining 810016,China;Qinghai Provincial Geographical Information and Natural Resources Comprehensive Survey Center,Xining 810001,China;Qinghai Titan Information Technology Co.,Ltd.,Xining 810000,China)

机构地区：[1]青海师范大学地理科学学院,青海西宁810016 [2]青海师范大学青海省自然地理与环境过程实验室,青海西宁810016 [3]青海省地理信息和自然资源综合调查中心,青海西宁810001 [4]青海提坦信息技术有限公司,青海西宁810000

出　　处：《自然灾害学报》2025年第2期47-55,共9页Journal of Natural Disasters

基　　金：海南州创新示范区黄河文化科技创新平台关键技术研究与示范项目(2024-HN-P04);三江源生态保护基金会2024年度科研项目。

摘　　要：2023年12月18日甘肃积石山县6.2级地震在青海省海东市民和县中川乡金田村和草滩村触发了一起典型地震液化型滑坡-泥流,造成了严重的灾害。本研究通过融合哨兵-2遥感数据反演的归一化差值含水指数(normalized difference moisture index,NDMI)时空演变特征、泥流沉积物组分分析及三维地形建模,揭示了积石山地震诱发金田村-草滩村泥流灾害的链式成灾机制。研究表明:孕震阶段(12月18日12时前)地下水位扰动与流体地球化学异常导致滑源区土壤含水量激增,NDMI指数异常攀升0.685;主震后10 min,泥流滑源区在应力失衡下发生土体崩塌,形成典型黄土地质泥流。该区域NDMI值于震后12月20日11时恢复至基线水平。研究进一步证实,坡度与浅层含水层的空间耦合是泥流灾害产生的核心诱因,而NDMI指数在孕震期的异常波动可提前7~12 h识别地震孕育信号,可以为黄土地区地震链生灾害预警提供量化决策依据。The M 6.2 earthquake in Jishishan County,Cansu Province on 18 December 2023 triggered a typical seismically liquefied landslide-mud flow in Jintian Village and Caotan Village,Zhongchuan Township,Minhe County,Haidong City,Oinghai Province,causing severe disasters.This study integrates the spatiotemporal.This study integrates the spatiotemporal evolution characteristics of the normalized difference moisture index(NDMI)derived from Sentinel-2 remote sensing data,compositional analysis of mud flow deposits,and 3D terrain modeling to reveal the chain disaster mechanism of the earthquake-induced mud flow.Results demonstrate that pre-seismic groundwater disturbances and hydrogeochemical anomalies(before 12:00 UTC+8 on 18 December)caused a sharp surge in soil moisture content(NDMI=0.685)at the source slip zone,as evidenced by NDMI anomalies.Approximately 10 minutes post-mainshock(23:59 UTC+8),stress imbalance triggered soil collapse in the mud flow source area,forming a typical loess-related mud flow.The NDMI values in the affected area returned to baseline levels by 11:00 UTC+8 on 20 December.The research confirms that the spatial coupling of slope conditions and shallow aquifers constitutes the core predisposing factor,while NDMI anomalies during seismogenic phases provide precursor signals(7~12 hours in advance)for earthquake prediction.This framework establishes quantitative criteria for early warning of earthquake-triggered chain disasters in loess regions.

关 键 词：积石山地震 泥流 归一化差值含水指数 土壤液化 地震前兆 

分 类 号：P315.9[天文地球—地震学] X43[天文地球—固体地球物理学]