Spatiotemporal distribution and evolution characteristics of successive landslides on the Heifangtai tableland of the Chinese Loess Plateau

Successive landslides leave geomorphic imprints on loess tableland edge hillslopes and dominate the morphologic evolution process. Here, on the basis of long-term landslide inventory, multitemporal unmanned aerial vehicle (UAV) surveys and field investigations, we examined the spatiotemporal distribution of successive landslides and their evolution characteristics in a typical loess tableland, Gansu Province, China. We found that the hot spots of successive landslides changed during the survey period and the hillslopes around the loess tableland experienced different evolutionary stages. Landslide areas are characterized by lower values of local relief, elevation and slope gradient than non-landslide areas and are more exposed to south, southeast and east orientations. Agricultural irrigation-induced successive landslides are responsible for the recession of the loess tableland area, which accelerates the morphological evolution process of the loess tableland. Under the influence of path dependency, more subsequent landslides may occur in a certain period. Moreover, this influence of earlier landslides on subsequent landslides (i.e., path dependency) will decrease with increasing time intervals (year). Two models (lateral and lengthwise development patterns) summarized in this study can describe the typical evolution processes caused by successive landslides in loess tableland areas. The findings of this research provide insights into the spatiotemporal distribution and morphologic evolution processes of agricultural irrigation-induced successive landslides, which is useful for understanding the evolutionary process in loess tableland areas.