44 / 2025-07-17 11:11:21

Terrace effect and prediction of landslides induced by the 2024 Ms 7.1 Wushi earthquake in Xinjiang, China

Terrace landslides,Tianshan Mountains,Ms. 7.1 Wushi earthquake,Terrace effect

On January 23, 2024, a magnitude 7.1 earthquake struck Wushi County in the southern Tianshan Mountains, Xinjiang, China, triggering numerous landslides on both terraces and non-terraces. Despite the significance of river terraces as distinct geomorphic features, their role in coseismic landslides remains insufficiently studied, and varying sampling strategies introduce uncertainty in susceptibility modeling. Therefore, this study analyzes the spatial distribution, characteristics, controlling factors, and susceptibility of terrace and non-terrace landslides across a 2894 km² affected area. Using remote sensing and field surveys, we compiled the first coseismic landslide inventory, identifying 4,009 landslides covering 15.68 km²—about one-third on river terraces. Both terrace and non-terrace landslides cluster in zones with specific topographic, geologic, hydrologic, and seismic conditions, but terraces show higher landslide area densities (LADs) and number densities (LNDs), a phenomenon termed the terrace effect. Terrace landslides preferentially occurred in areas with intermediate elevations, hillslopes with steep gradients, low-elevation depressions, and high peak ground acceleration values. Under the two different sampling strategies, the landslide susceptibility assessments performed using the Bayes network, decision table naive Bayes and radial basis function classifier models demonstrate that source-based machine learning models achieve superior predictive performance compared with mass-based models. The tectonic geomorphic conditions of the Wushi earthquake-induced landslides are macroscopically controlled by regional uplift and river erosion, whereas earthquakes provide direct triggers for landslide occurrence. The clustering and size of terrace landslides are controlled by the terrace effect.