Test analysis on disturbances caused by urban rail transit at geoelectric stations and measures to reduce its influence

Geoelectric resistivity observation is one of the important means for earthquake precursor observation. Before the Tangshan earthquake, Songpan earthquake, Lancang-Gengma earthquake and the 2008 Wenchuan earthquake, obvious geoelectric resistivity anomaly had been observed. But with the rapid development of national economy, geoelectric resistivity observation environment has met various kinds of disturbances, especially the disturbance from urban rail transit that uses DC traction power supply system, and some observation stations had to be relocated because their records could not meet standard requirements. In this study, we conducted an analysis on the anti-disturbance capability of the current observation system in China by analyzing the disturbance caused by urban rail transit at two geoelectric stations, and proposed some measures to reduce its influence on geoelectric observation.