Using SBAS-InSAR and Audio-Magnetotelluric Sounding to Characterize Two-Dimensional Deformation and Failure Mechanisms in Mining-Induced Landslides

Mining-induced geological hazards in the mountainous regions are often characterized by wide impact zones and complex subsurface structures, which pose significant challenges for the precise identification of landslides and the analysis of their formation mechanisms. To address this issue, we takes the Leji landslide in southwestern China  as a case study and integrates SBAS-InSAR technology, two-dimensional decomposition modeling, UAV photogrammetry, field geological investigation, and AMT sounding to establish a multidimensional “Space-Air-Ground-Subsurface” detection strategy. This multi-dimensional framework enables the systematic acquisition of both surface deformation and subsurface structural information of the Leji landslide, thereby elucidating its controlling factors and causative mechanisms. The results reveal that the central parts of Landslide I and Landslide II exhibit the most significant deformation, with surface displacement dominated by downslope subsidence. The maximum annual average subsidence rates range between –60 mm/y and –80 mm/y. The cumulative deformation zones retrieved by SBAS-InSAR closely coincide with the mining areas detected by AMT. Through data fusion, the boundary angles of the mining areas were determined as 77° in the upslope direction and 48° in the downslope direction along the dip, and 77° and 55° in the strike direction. Comprehensive analysis indicates that the Leji landslide is a Quaternary soil creep landslide formed under the combined influence of fault–fold structures, frequent heavy rainfall, and both open-pit and underground mining activities, and it remains in an active state. This study demonstrates that the “Space-Air-Ground-Subsurface” collaborative observation system effectively overcomes the limitations of single techniques in landslide mechanism research, providing a reliable technical pathway and scientific basis for understanding the development mechanisms and disaster risk mitigation of mining-induced landslides.