Reactivation and dynamic process prediction of the Woda landslide in the upper Jinsha River Basin, China.

The ancient Woda landslide, located in the upper Jinsha River, China, is a reactivated landslide that poses a potential risk of further instability and river blockage. In this study, we evaluated and modeled the reactivation characteristics, potential instability, dynamic runout, and resulting dam stability of the Woda landslide. Our results show that the landslide is currently experiencing creep, although accelerated deformation is occurring locally. The presence of two sliding zones suggests the potential reactivation of the landslide through a progressive failure mechanism along either a shallow or deep sliding zone. Under these two scenarios, the Woda landslide would form a dam and block the Jinsha River, with maximum modeled runout distances of approximately 1800 and 2110 m, and dam heights of approximately 25 and 62 m, respectively. The resulting backwater areas would reach upstream distances of approximately 13 and 30 km, and the maximum modeled peak flood discharge following a breach scenario would be 2772 and 5102 m³/s, respectively. These results provide an important reference for predicting and managing large geological disaster chains in the upper Jinsha River Basin. [ABSTRACT FROM AUTHOR]