Influence of topography and volume on mobility of loess slides within different slip surfaces

- The mobility of loess slides shows positive correlation with magnitude.
- Travel distance significantly increases with increasing fall height.
- The negative power law correlation is observed between the travel distance and slope inclination.
- The red clay contact landslides have higher mobility than landslide in loess and bedrock contact.

Mobility of loess slides has been evaluated using an empirical approach based on a detailed field investigation and remote sensing image interpretation. For all the loess slides, the affected area increases with increasing loess slides volume. From the statistical analysis it is seen that the travel distance has an increasing trend, while the coefficient of friction has a decreasing trend with the increase in landslide volume. Landslide volume determine its travel distance and coefficient of friction, that can be shown with a regression equation having simple power law form, which indicates that the mobility of loess slides increases with increasing volumes. By analogy, the greater the energy of the sliding loess mass, the stronger is the mobility of loess slide. A plot of the travel distance of loess slide versus fall height shows a significant positive power law correlation indicating the increase in mobility of loess slide with fall height. The negative power law correlation observed between the travel distance and slope inclination implies that the mobility decreases with the increase of slope inclination. Three datasets of loess slides characterized by different slip surfaces were distinguished. The red clay contact landslides have the strong mobility than landslides in loess and bedrock contact.