Typical characteristics of large-scale landslides in the transition belt between the Qinghai-Tibet Plateau and the Loess Plateau

The transition belt between the Qinghai-Tibet Plateau and the Loess Plateau is an area where geohazards occur frequently. To develop a basic understanding of the geohazards in this region, a detailed field investigation of large-scale landslides (i.e., > 106 m3 in volume) has been performed. The results show that 259 large-scale landslides have occurred in this region, of which 254 landslides are rock landslides and the others are soil landslides. These landslides have an average volume of 20.6 Mm3, are mainly concentrated along rivers, and have a linear density that reaches 0.45 landslides/km. Furthermore, more than 90% of the landslides are located within 5.0 km of a fault and more than 80% of the landslides are located at elevations of 1000–2600 m. With increasing landslide volume, the mobility increases, and approximately 45% of the landslides are sturzstrom-type landslides. Large-scale landslides are mainly concentrated along faults, especially around fault intersections. The typical failure mechanisms of the studied landslides are clearly influenced by the regional structure, earthquakes, and river incision.