降雨对昌黎台地电阻率的干扰分析

Quantitative Analysis of Rainfall Effects on Earth Resistivity in Changli Seismic Station

昌黎台地电阻率受降雨影响明显,降雨量越大,地电阻率下降幅度越大,两者存在良好的线性关系。基于昌黎台电测深资料反演的水平层状均匀介质结果,建立地表薄层电性结构变化模型,通过影响系数理论定性分析降雨对地电阻率的即时效应,研究结果显示降雨主要是通过改变地表介质含水量和电性结构造成地电阻率变化的。利用褶积滤波法定量模拟降雨对地电阻率的短期影响过程,可以较好去除降雨对地电阻率的即时影响和滞后响应。

Rainfall has an obvious effect on earth resistivity at Changli seismic station. There is a good linear relationship between them, with the increase of rainfall while the decrease of earth resistivity. Based on electric sounding data and lithologic data in Changli seismic station, a physical model was built by using the influence coefficient theory to qualitatively analyze the immediate effect of rainfall on earth resistivity. The results show that rainfall mainly changes the water content and electrical structure of surface media and affect the earth resistivity finally. The convolution filtering method is useful to simulate the short-term effect and remove the immediate influence and lag response of rainfall on the earth resistivity.