摘要
水库地震是由人类工程活动引发的地震活动,具有群发性、高频次和大烈度的特点,对其进行预测研究有助于评估水库地震灾害风险。将三峡工程水库地震重点监视区划分为若干个1 km×1 km的预测单元,运用贝叶斯概率统计预测模型,依据库水深度、岩体类型、区域构造应力状态、断层活动性、岩溶发育程度、库水透水深度、与库水沟通关系、地震活动背景8个诱震因素,预测诱发震级的概率。结果表明:在重点监视区,以碳酸盐岩为主的库岸附近区域,诱发地震概率较高;仙女山断裂北端、高桥断裂近库岸段及牛口断裂近库岸段,存在诱发中强震(6.0>M3≥4.5)的可能;而三峡坝址区和远离库岸区域,不发震或诱发微震的概率较高。使用三峡水库175 m蓄水以来的实际地震情况对预测模型进行检验,结果表明实际地震的发生地点及震级与预测结果存在明显的一致性,采用精细划分方式的贝叶斯概率统计预测方法在水库诱发地震危险性评定方面具有很好的效果。研究的概率预测结果对于确定地震风险区域、制定地震预警和防范策略,以及保障水库工程的安全运行具有重要参考意义。
Reservoir-induced earthquakes,which are characterized by swarm-like occurrence,high frequency,and significant intensity,are triggered by human engineering activities.The prediction and research on these earthquakes are crucial for assessing the seismic hazards of a reservoir.This study applies a Bayesian probability statistical prediction model to key monitoring areas of the Three Gorges Reservoir,which are divided into several prediction units of 1 km×1 km.Eight seismogenic factors were considered,including reservoir water depth,rock type,regional tectonic stress state,fault activity,karst development degree,water penetration depth,hydraulic connection with the reservoir,and seismic activity background.The results indicate the following:First,areas near carbonate-rock-dominated reservoir banks exhibit higher probabilities of induced earthquakes.Second,the northern end of the Xiannüshan fault and the reservoir bank and proximal sections of the Gaoqiao and Niukou faults show potential for moderate earthquakes(6.0>M 3≥4.5).Finally,the Three Gorges dam area and regions that are distal to the reservoir bank have higher probabilities of nonseismicity or microearthquakes.The proposed model is validated using seismic records after the impoundment of the Three Gorges Reservoir(at the 175-m water level),revealing high consistency between predicted and observed earthquake locations and magnitudes.The Bayesian probability statistical prediction method with rational subdivision has a favorable effect on the risk assessment of reservoir-induced earthquakes.The probabilistic prediction results provide crucial references for delineating seismic risk zones,formulating earthquake early warning and prevention strategies and ensuring the safe operation of reservoir projects.
作者
凌江筑
廖欣
姚运生
石云
钱建秀
胡陈悦
秦维秉
LING Jiangzhu;LIAO Xin;YAO Yunsheng;SHI Yun;QIAN Jianxiu;HU Chenyue;QIN Weibing(Institute of Disaster Prevention,Sanhe 065201,Hebei,China;Hebei Key Laboratory of Earthquake Dynamics,Sanhe 065201,Hebei,China;Hebei Key Laboratory of Resource and Environental Disaster Mechanism and Risk Monitoring,Sanhe 065201,Hebei,China;Institute of Geophysics,CEA,Beijing 100081,China;China Three Gorges Corporation,Beijing 100038,China)
出处
《地震工程学报》
北大核心
2025年第4期901-910,共10页
China Earthquake Engineering Journal
基金
地震科技星火项目(XH23063A)
国家自然科学基金(41602274,42174177)
中国长江三峡集团有限公司项目(0799217)
防灾科技学院2020年度重点实验室开放基金项目(FZ202208)。
关键词
水库地震
贝叶斯统计预测法
三峡工程水库重点监视区
诱震因素
reservoir-induced earthquake
Bayesian statistical prediction method
key monitoring areas of the Three Gorges Reservoir
factors inducing earthquake
