A brief discussion on the interference and elimination of rainfall to the water pipe inclinometer at Fengning station

Observation data of DSQ water pipe inclinometer and meteorology at Fengning seismic station from 2021 to 2023 were selected. Correlation analysis and convolution filter analysis were performed on rainfall and observation data, and convolution filter method and regression analysis were used to eliminate the lag effect of rainfall, and the relationship between rainfall and water pipe stress variables was judged. The results show that the trend change of the Fengning DSQ water pipe inclinometer was related to rainfall, and the daily variation of the observed data had a good linear relationship with the rainfall accumulation value, but did not obviously correlate with the instantaneous rainfall, and the response time had a lag of 1 day. Convolution filtering can better eliminate the step change caused by rainfall, but it failed to completely eliminate the southward inclination of NS and eastward inclination of EW after the rainfall of the water pipe meter from June to September 2021. Other factors may also affect the inclination of NS to S and EW to E of the water pipe meter.