陕西周至地电台地电阻率年变特征分析  

Annual variation characteristics of georesistivity at Zhouzhi geoelectric station,Shaanxi Province

作　　者：石富强[1] 张国强[1] 方炜[1] 邵辉成[1] 张国苓[2] 

机构地区：[1]陕西省地震局,中国西安710068 [2]河北省地震局,中国石家庄050021

出　　处：《地震学报》2014年第6期1113-1123,共11页Acta Seismologica Sinica

基　　金：陕西省地震局启航与创新基金课题(201304);陕西省地震局青年科研基金课题(201203);中国地震局监测预报司震情跟踪青年课题(2013020402)共同资助

摘　　要：本文基于测深反演结果,通过数值模拟定性分析了地下水位和降雨对周至地电台地电阻率观测的影响;同时利用褶积算法定量分析了降雨对该台NS向和NE向地电阻率观测的短期影响和长趋势影响.结果表明,周至地电台地电阻率年变主要由地表薄层介质电阻率季节变化引起,受地下水位变化影响不明显.降雨对NS向和NE向地电阻率观测值的影响在短期内与观测结果一致,表现为增加;但长期趋势则与观测结果呈负相关关系.根据数值模拟分析认为,这种变化与降雨及其渗透深度有关.分析结果与实际观测结果一致,为正确认识周至地电台地电阻率观测与异常判定提供合理的理论依据.Based on the vertical electric soundings of Zhouzhi geoelectric station, the effects of groundwater and rainfall on georesistivity are qualitatively simula-ted by finite element analysis.Meanwhile,the long-term and short-term effects of rainfall on the NS-and NE-direction georesistivity are also analyzed by the convolution function.The results show that the annual variation of georesistivi-ty at Zhouzhi geoelectric station is mainly caused by the seasonal variation of the surface resistivity,and has little relationship with the groundwater level.The effects of rainfall on the NS-and NE-direction georesistivity are consistent with the georesistivity observations and show a tendency to increase after rain for a short time,while display a negative correlation with the long-term observa-tions.According to the qualitative simulation results,this reversed change is mainly due to the deepening of penetration depth.All these analyses are con-sistent with the observations,providing a reference to understanding the annual and abnormal variations of georesistivity at Zhouzhi geoelectric station.

关 键 词：地电阻率 年变 降雨 地下水位 数值模拟 褶积 

分 类 号：P315.72[天文地球—地震学]