Distribution and impoundment response law of landslides in the reservoir area of Wudongde Hydropower Station

Abstract

[Objective] The impoundment operation of the Wudongde Hydropower Station has caused significant landslide deformation. In order to find out the development characteristics of landslide and the water storage response law of wading landslide deformation, [Methods] SBAS-InSAR, optical remote sensing interpretation, field surveys, mathematical statistics and theoretical analysis were used to study the number, development characteristics, deformation patterns and trend of landslides induced by the impoundment of the Wudongde Hydropower Station. [Results] The result show that there are 62 landslides along the coast of Wudongde Reservoir, including 39 water-related landslides. These landslides are concentrated in Jurassic, Cretaceous red beds and Proterozoic shallow metamorphic rock areas. The slope of the landslide is 10°~40°, the height difference between the front and rear edges is 200~800 m, the slope types are mostly convex forward-facing slopes, with linear or fold line sliding surfaces being predominant. A total of 114 obvious deformations have occurred in 39 water-related landslides since the initial impoundment, and the maximum deformation rate is 63.72 mm/a. Currently, the number of landslide deformation and deformation rate are increasing year by year, which is in the active stage. The deformation trend of landslide is categorized into accelerated deformation, uniform deformation, and deceleration stabilization deformation. Among them, the accelerated deformation landslide accounts for 61.54%, which is dominated by the landslide with a straight line and a high degree of wading. Its water storage response is significant and the deformation is large. The influence of reservoir water level decline on landslide is greater than that of reservoir water level rise. [Conclusion] The deformation law of Wudongde reservoir landslide is revealed, which provides a scientific basis for the prediction and prevention of reservoir landslide disaster.

Keywords

Wudongde Hydropower Station / landslide / development and distribution / deformation law / development trend / geological hazards / influencing factors / reservoir storage