Due to the significant seasonal permafrost stratification phenomenon in the desert-gobi-wasteland area

which has a significant impact on the electric field distribution characteristics of ultra-high voltage direct current grounding electrodes

a real-time monitoring platform for soil resistivity based on the Wenner four-electrode method is established in a typical permafrost area of Inner Mongolia to obtain and analyze annual soil resistivity data. The results show that soil resistivity is strongly negatively correlated with temperature

and the resistivity of frozen soil layers in winter can reach 2.68 times that of summer. Based on the theoretical derivation and CDEGS software simulation modeling

the influence of frozen soil layer on the distribution of grounding electrode electric filed is analyzed

and a three-layer soil simulation calculation model during the thawing period is proposed. The results indicate that soil freezing leads to a significant increase in electrical resistivity

and the step voltage and leakage current around the grounding electrode seriously exceed safety limits. When the thickness of the frozen soil exceeds the burial depth of the grounding electrode

the surface potential and step voltage exhibit non-linear growth characteristics

with smaller soil reflection coefficients leading to more severe increases. During the thawing period

the surface potential and step voltage show a decreasing trend followed by an increasing trend with the thickness of the thawed layer.