Dynamic process, influence and triggering mechanism of remolding landform by landslide clusters in South Jingyang Tableland, China

In recent decades, loess landslides (clusters) induced by agricultural irrigation activities are accelerating the evolution of the loess tableland. However, how loess landslides (clusters) remodel the tableland has not been fully discussed in the previous studies. The lack of such research hinders people’s understanding of the role and mechanism of landslides in the geomorphological evolution of the modern Loess Plateau. In this paper, taking South Jingyang Tableland, Shaanxi Province, China as an example, through remote sensing interpretation, landslide monitoring (including remote sensing satellite monitoring, remote online monitoring and 3D laser scanning), electrical resistivity tomography (ERT) survey, field survey and sampling, geomorphic change detection (GCD) and numerical simulation, we try to conduct multidisciplinary study to reveal the dynamic evolution of landslides (groups) in South Jingyang Tableland and their influence on the tableland landform. This study revealed the temporal and spatial distribution of landslides in the study area and the dynamic change of the tableland edge. It is found that since 1974, the area of the tableland eroded by landslides has reached 221, 320 m², and the maximum retreat of the tableland edge is 139.6m and the maximum retreat rate is 2.97m/yr. The hydrogeological structure of five profiles was found out by means of ERT surveys, which provides important evidence for identifying the distribution and migration channels of the groundwater. We successfully monitored the processes of three landslides using multi-temporal data of terrestrial laser scanner (TLS) surveys and estimated the impact of these landslides on geomorphic changes. Using the on-line monitoring equipment installed at the top of L3 landslide, we realize that the tilt deformation process of L3 landslide top is not a single linear trend, but a complex deformation process. Finally, we use Massflow software to simulate the movement process of L3 landslide and reconstruct the likely stages of the L3 landslide development. On the one hand, this study provides a reference for the monitoring of landslides in loess tableland, on the other hand, it provides a scientific support for the study of interaction between loess landslides and geomorphic evolution.