## 3 Results  
### Measured Results and Geological Interpretation  
After obtaining measured data from four survey lines, the present study employed the Res2 dinv software to interpret the data, resulting in the derivation of four inversion results (Figures 6 and 7). Based on geological and drilling data, the analysis reveals that the landslide body exhibits clear stratification. The upper layer consists of Quaternary slope residual deposits, which are gravelly clay with resistivity ranging from 1200-2500 \(\Omega\cdot\)m. However, from the foot to the top of the slope, the gravel content in the surface clay gradually increases, with the rock component being siltstone. In the rear part of the landslide, the gravel content reaches around 35%, which also leads to a higher resistivity in the surface layer of the landslide body, ranging from 2500-8000 \(\Omega\cdot\)m. This can be observed by comparing the profiles in Figure 6 and line \"i\" and line \"j\" in Figure 7. The second layer consists of siltstone and sandy shale with a resistivity range of 600-1200 \(\Omega\cdot\)m, which is also the formation where the sliding bed is located. The third layer is limestone, and drilling data reveal that the local limestone formation has karst development, resulting in high water content within the limestone formation and thus a resistivity lower than 600 \(\Omega\cdot\)m.  
Figure 5: Topographic map of Lijiazu landslide and the layout of geological survey. Figure 6: ERT profile of line “\(a\)”. LRZ: low-resistivity zone; HRZ: high-resistivity zone. Figure 6 presents the electrical resistivity tomography along profile line \"a\" of the landslide. Due to the contrasting electrical properties of the geological layers, the resistivity profile can effectively delineate the morphological characteristics of the sliding surface. Based on the analysis of drilling data, it can be determined that the slip surface is located within a sandy shale formation with a resistivity ranging from 600-1200 \(\Omega\cdot\)m. The overall depth of the slip surface remains relatively consistent between 7 to 8 m. There is a high-resistivity anomaly on the surface at positions ranging from 145 to 190 m. This anomaly is attributed to the increased content of surface gravel in the upper part of the landslide body, with the majority of gravel having diameters between 3 and 15 cm. Occasionally, larger boulders with diameters exceeding 30 cm are observed, contributing to the increased electrical resistivity on the surface behind the landslide (HRZ-1 in Figure 6). Within a range of approximately 200-220 m from the starting point of the survey line, a significant high-resistivity anomaly was detected underground (HRZ-2 in Figure 6). Analysis of geological data indicates that this anomaly corresponds to the rear edge of a landslide, characterized by a prominent fissure. Thus, the presence of the high-resistivity anomaly can be attributed to this geological feature. Figure 7 presents the inversion result of the landslide along three survey lines, namely \"n\", \"i\", and \"j\". By examining the resistivity profiles of four survey lines, it can be observed that the geological information reflected at these common points is consistent. From the  
Figure 7: ERT profile of line “h” (**a**), line “i” (**b**), line “j” (**c**). LRZ: low-resistivity zone; HRZ: high-resisitivity zone. resistivity profile, it is evident that the surface resistivity of lines \"h\", \"i\", and \"j\" gradually increases. This also corresponds to the actual situation where the content of gravel in the superficial clay layer increases continuously from the base to the top of the slope (HRZ-1 in Figure 7).