The Impact of Rainfall on the Earth's Resistivity Observations at Baochang Platform
The annual variation of the resistivity observations along the NS and EW profiles at Baochang Seismic Station exhibits a pattern of low values in summer and high values in winter.Summer rainfall induces short-term changes in the observations with a rapid onset and slow recovery.To further investigate the characteristics of these changes and considering the subsurface electrical structure of the station and regional rainfall data,the impact coefficient theory and convolution filtering method are employed to ana-lyze the influence of rainfall on the resistivity observations at Baochang Station.The results indicate that the impact coefficient of the near-surface media in the station's measurement area is positive,and the resistivity observations change in the same direction as the true resistivity of the near-surface media.The convolution filtering method,based on rainfall data,fits well with the observed annual variation,suggesting that rainfall is the main cause of the annual changes in resistivity at Baochang Station.