Probability Assessment of Potential Landslides Under the Coupling of Earthquake and Rainfall—A Case Study of Zhouqu Area, Gansu Province, China

Earthquakes and rainfall are considered two of the major causes of landslides worldwide. These landslides cause billions of dollars in property damage and revenue losses, as well as the deaths of thousands of people each year. While researchers have been examining the effect of either rainfall or earthquakes on the deformation and stability of slopes, the combined effect of earthquakes and rainfall on deformation and slope stability has not been evaluated systematically. In this paper, we present an approach to generating probabilistic hazard maps for potential landslides using the Newmark displacement model (NDM), which considers earthquakes and rainfall. Also, we have conducted an in‐depth analysis of uncertainties and fluctuations in the input parameters of NDM through Monte Carlo techniques. Taking Gansu Province of China as an example, probability distribution maps were generated separately under different conditions of rainfall combined with a 10% failure probability of ground motion in 50 years. The results show that rainfall has a significant influence on landslide risk under the same horizontal ground motion input condition. With the increase in daily rainfall, the proportion of landslide area in high‐risk areas also increased sharply, while that in low‐risk areas also decreased significantly, which can serve as a basis for providing a reference for the prediction of earthquake‐induced landslides during rainy seasons.