###### Abstract  
Electrical resistivity tomography is a non-destructive and efficient geophysical exploration method that can effectively reveal the geological structure and sliding surface characteristics inside landslide bodies. This is crucial for analyzing the stability of landslides and managing associated risks. This study focuses on the Lijiazu landslide in Zhuzhou City, Hunan Province, employing the electrical resistivity tomography method to detect effectively the surrounding area of the landslide. The resistivity data of the deep strata were obtained, and the corresponding geophysical characteristics are inverted. At the same time, combined with the existing drilling data, the electrical structure of the landslide body is discussed in detail. The inversion results reveal significant vertical variations in the landslide body's resistivity, reflecting changes in rock and soil physical properties. Combined with geological data analysis, it can be concluded that the sliding surface is located in the sandy shale formation. Meanwhile, by integrating various geological data, we can conclude that the landslide is currently in a creeping stage. During the rainy season, with rainfall infiltration, the landslide will further develop, posing a risk of instability. It should be promptly addressed through appropriate remediation measures. Finally, based on the results of two-dimensional inversion, this article constructs a three-dimensional surface morphology of the landslide body, which can more intuitively compare and observe the internal structure and material composition of the landslide body. This also serves as a foundation for the subsequent management and stability assessment of landslides, while also paving the way for exploring new perspectives on the formation mechanisms and theories of landslides. landslides; geophysics; ERT; sliding surface +
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Taking Hunan Province as an example, a total of 2884 geological hazard events occurred in 2022, with landslides accounting for a significant proportion of 88.8% (2561 events). The geological environment in Hunan Province is mainly composed of residual slope deposits, which exhibit a loose structure and good permeability. As a result, the infiltration of rainfall significantly reduces the shear strength of the soil. Especially when bedrock serves as an aquiclude, it can lead to the formation of a groundwater barrier at the contact interface, potentially triggering soil sliding. These geological conditions contribute to the prevalence of small-scale soil landslides in the province, with over 90% occurring during the rainy season [9]. In this study, the Lijiazzu Landslide is a typical case of a small-scale soil landslide. This landslide is particularly active during the rainy season, leading to ground swelling and cracks in residential retaining walls. This poses a serious threat to the lives and property of residents. Today, there are numerous technologies available for landslide investigations, each with its own characteristics. Aerial and satellite methods (digital aerophotogrammetry, GPS, differential interferometric) provide information about slope surface features such as topography, morphology, landslide area, and displacement [10; 11; 12; 13; 14]. However, they do not offer any information about subsoil characteristics. On the other hand, direct field techniques (such as pressure gauge and displacement meters) can give us insights into the physical deformation of landslides but are limited to specific points on the landslide [15; 16]. Geophysical methods can measure direct or indirect physical parameters related to landslide development, such as rock type and hydrology. These techniques are less invasive than previous methods and can provide more comprehensive information, overcoming the scale limitations of traditional geotechnical techniques [17; 18].