QIN Shi-he, DUAN Bin, WANG Hai-sheng, LI Mei-ping, WEI Chang-li
To comprehensively understand the characteristics and distribution of geological hazards at the Jinchuan Hydropower Station located upstream of the Dadu River and its surrounding regions, we focused our research on a 40-kilometer section encompassing the dam and reservoir area, main stream, and tributaries. Employing 1∶10 000 high-precision remote sensing image interpretation, unmanned aerial vehicle (UAV) photography, engineering geological surveys, and profile measurements, we classified and quantified geological disasters, and further examined the correlations between geological hazards and various disaster-inducing factors including topography, geological structure, engineering geological rock formations, slope structure, and hydrogeological conditions. Our findings identified 38 geological hazards. The predominant hazard types were debris flows, collapses, riverbank failures, unstable slopes, and landslides. Debris flows and collapses were the most frequent, constituting 28.9% and 23.7% of the occurrences, respectively. Specifically, collapses, landslides, unstable slopes, deposit bodies, and riverside collapses predominantly occurred in the Dadu River valley at elevations below 2 600 meters. Landslides and unstable slopes typically located at slope gradients between 25° and 45°, collapse-prone areas generally had slopes greater than 50°, and deposit bodies and riverside collapses developed on slopes ranging from 20° to 35°. The majority of geological hazards were found in areas with relief fluctuations between 200 m and 500 m. Significantly, 48.1% of the hazards occurred on slopes with planar curvature, while 59.3% were associated with slopes having profile curvature. Eight rock groups were identified within the study area, with most geological disasters occurring within 100 meters from the river. These results provide a more scientific and accurate foundation for regional geological disaster prevention and mitigation strategies.
