Effect of climate change induced extreme precipitation on landslide activity in the Three Gorges Reservoir, China

Abstract

Climate change has caused an increase in extreme rainfall and snowfall in many parts of the world. For example, in the Three Gorges Reservoir area, annual precipitation has gradually increased and the occurrence of heavy precipitation events has become more frequent. As the reservoir water level rises in October, the high water combined with heavy precipitation creates a "special hydrological environment," which recently caused the Yanguan landslide. The Yanguan landslide is a large-scale soil landslide that has undergone two slides, pushed the Yanguan Road Bridge into the reservoir, and caused serious damage to roads and buildings. In the present study, the combined effects of high water and heavy precipitation on landslide deformation characteristics (movement patterns and evolution processes) have been analyzed and a stability evaluation was conducted through a field investigation and numerical simulation. To comparatively analyze these combined effects of high water and heavy precipitation, a two-dimensional finite element model was created, and four cases of the hydrological environment were calculated with the model. Results show that the factor of safety was maintained in the range of 1.013 to 1.059 before the precipitation conditions changed. However, as heavy precipitation increased in October 2017 (reaching 356.4 mm in 1 month), this "special hydrological environment" potentially decreased the FoS to 0.948, which is 9.6% lower than that observed under normal conditions, and helped drive the Yanguan landslide activity. The analysis of these various combined effects can also indicate the impacts of climate change on landslides in other areas of the Three Gorges Reservoir.

Impact of precipitation on Beishan landslide deformation from 1986 to 2023

“…An escalation in the occurrence of extreme rainfall events in alpine regions can intensify the occurrence of landslides (Shah et al, 2023). Beyond the direct erosive impact of rainfall, extreme precipitation can also induce landslides by influencing the hydrology of the watershed (Zhu et al, 2021). Most landslides in this part of the plateau are triggered by rainfall (Li et al, 2023;Peng et al, 2015).…”

Stability Prediction of Rainfall-Induced Shallow Landslides: A Case Study of Mountainous Area in China

“…In China, many large-scale landslides were triggered by heavy rainfall, such as the Yigong landslide [10], rockslide debris in the Wenchuan earthquake area [11], and Yanguang and Shaziba landslide in Hubei [12,13]. However, shallow landslides (generally lower than 2 m) are the primary and common phenomena worldwide.…”

Impact of climate change on shallow ground hydro-thermal properties

“…While the impact of extreme weather on infrastructure is more pronounced, changes in average climate conditions also significantly affect geotechnical infrastructure. Zhu et al (2021) studied the effect of climate change-induced heavy rainfall events on landslides in China and found that the factor of safety significantly drops under future climate. The gravity of soil erosion in Iran is set to change under the predicted rainfall patterns (Doulabian et al 2021).…”