Numerical Analysis of Nonuniform Geoelectric Field Impacts on Geomagnetic Induction in Pipeline Networks

Modeling the geomagnetic induction in pipeline networks is essential for the risk assessment and management of geomagnetic disturbances. The induced geoelectric field (GEF) is usually spatially nonuniform, depending on the distribution of the geomagnetic variation and the earth conductivity. However, few studies have been conducted on the induction in complex pipeline networks with nonuniform GEF. In this article, a calculation model for induction in pipeline networks with nonuniform GEF is proposed by utilizing the modified equivalent-pi circuits. Then, the proposed model is used to investigate the distribution of pipe-to-soil potentials and geomagnetically induced currents in the pipeline network under several typical nonuniform GEF scenarios due to geomagnetic source fields, including local enhancement and spatially gradual variation. Furthermore, taking the coast effect as a typical case, the influence of the lateral variation of earth conductivity on the induction is analyzed. The results show that the nonuniform GEF may greatly affect the induction results in the local parts of the pipeline network.