Insights into Reservoir-Triggered Landslides Development and Its Influence Factors in the Three Gorges Reservoir Area, China

More than 5 000 landslides or potential landslides have been triggered in the Three Gorges Reservoir (TGR) area since the impoundment in 2003. This study aims at investigating the reservoir-induced landslides spatiotemporal and size distribution and its influence factors in the TGR by taking 790 landslides as statistical samples. The landslides exhibit significant regional and sub-regional spatial differences, and numerous landslides occurred at the initial three impoundment stages and the corresponding 2–3 cycles of reservoir operations followed, but the landslide frequency decreased dramatically after 2010 from temporal perspective. The relationship between landslide development and topographical, geological as well as hydrological factors were analyzed qualitatively. The reservoir-induced landslides in TGR area exhibit self-organized criticality and the rollover is nearly 2.5 × 10⁴ m², which could not be attributed to the missing data but the coupled influences imposed by affecting factors. Both the double Pareto and inverse gamma functions are more suitable than the power-law function to present the landslide size characteristics. In term of the fitting precious, the adaptability of the inverse gamma function is better if the landslide inventories are limited. The research results provide foundation for the landslide susceptibility maps and hazard risk assessment.