Spatial distribution and its impact factors of loess–red bed landslides in the Longzhong Basin, China

The Longzhong Basin (LZB), located on the northeastern margin of the Tibetan Plateau, is characterized by active tectonic structure, significant terrain differences, and uneven precipitation, all of which contribute to the prevalence of loess–red bed landslides (LRBLs). Analyzing the spatial distribution and its impact factors of LRBLs is essential for landslide risk management and prevention. In this study, the spatial clustering pattern of LRBLs and the relationships with nine impact factors including topographic, geological, and hydrometeorological factors were analyzed based on the ArcGIS platform. The results indicate that the distribution of LRBLs exhibits significant clustering characteristics, with seven landslide concentration zones being delineated. These landslides predominantly occur in areas characterized by the elevations of 1600–2400 m, slopes of 10°–20°, terrain relief of 90–150 m, and annual precipitation of 400–480 mm. In addition, areas located within 1.0 km of rivers, 10 km of faults, and 20 km of epicentres emerge as particularly susceptible to landslide development. According to Varnes's motion patterns classification, LRBLs were divided into two types: slides and flows. Slides include rotational, translational, and rotational-translational landslides, while flows cover mudflow and flow slides. The findings are of great significance for the further understanding of LRBLs in the LZB.