摘要
华北作为中国大陆强震区,同时也是我国人口最多的平原,20世纪60年代以来经历了大规模的地下水开采.本文基于华北平原1959—2016年地下水水位变化,结合区域地质背景建立了有限元孔隙弹性模型,定量分析地下水开采对区域地震活动性的影响.结果显示,地下水开采引起的卸载作用导致区域地壳隆升,最大约35 mm,同时在垂直方向上产生拉伸,地下10 km深度处拉应力最大达92 kPa.根据华北地区历史地震震源参数计算库仑应力变化,结果表明地下水弹性卸载增大了断层面上的正应力,但开采引起的孔隙压力减小使开采区内库仑应力变化为负,而开采区外结果为正.通过分析认为库仑应力变化结果受断层产状、位置等的影响,华北平原地下水开采减小了该地区强震发生的可能性,但随着开采速率放缓及未来可能的水位抬升,会对区域地震活动性产生进一步影响.
As a strong earthquake area in China's Mainland,the North China Plain(NCP)is also the most populous plain in China.Since the 1960s,this area has experienced large-scale groundwater mining.Based on the groundwater level change in NCP from 1959 to 2016,combined with the regional geological background,we established a pore elasticity model to quantitatively analyze the influence of groundwater mining on regional seismic activity.The results show that the groundwater unloading leads to crustal uplift,with a maximum of about 35 mm.And extensional stress changes in the vertical direction up to 92 kPa at a depth of 10 km.The results of the Coulomb stress changes calculated by the focal parameters of historical earthquakes in NCP show that elastic unloading increases the normal stress on the fault plane,but the decrease of pore pressure makes the Coulomb stress changes negative in the mining area,while the results are positive outside the mining area.Through the analysis,the results of Coulomb stress changes are affected by the fault parameters and location,the groundwater mining in NCP reduces the risk of great earthquakes.However,with the slowdown of the mining rate and the possible groundwater level rise in the future,it will further affect the regional seismic activity.
作者
窦甜甜
程惠红
周元泽
石耀霖
DOU TianTian;CHENG HuiHong;ZHOU YuanZe;SHI YaoLin(Key Laboratory of Computational Geodynamics,College of Earth and Planetary Sciences,University of Chinese Academy of Science,Beijing 100049,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第8期2931-2944,共14页
Chinese Journal of Geophysics
基金
国家重点研发计划(2018FYC1504205)
中央高校基本科研业务费专项资金(Y95401SXX2)联合资助。
关键词
华北平原
地下水开采
应力变化
地震活动性
North China Plain(NCP)
Groundwater mining
Stress change
Seismicity
