The Effect of Aspect on Landslide and Its Relationship with Other Parameters

Aspect is one of the parameters used in the preparation of landslide susceptibility maps. The procedure of this easily accessible and conclusive parameter is still a matter of debate in the literature. Each landslide area has its own morphological structure, so it is not possible to make a generalization for the aspect. In other words, there is no aspect in which landslides develop in particular. Generally, landslides occur in areas facing more than one direction. The biggest reason for this is that those areas are under the influence of other parameters. Therefore, it is wrong to evaluate the aspect, alone. Since it is a part of the system, it should be evaluated together with other conditioning factors. In this research, many landslides susceptibility studies have been investigated. The directions and causes of landslides have been determined from the studies. In addition, the criteria of the used aspect classes have been investigated. In the literature, the number of class intervals chosen, and their reasons were investigated, and the effects of this parameter were tried to be revealed in new sensitivity studies.

Assessment of Landslides Susceptibility in Giri Watershed, Northwest Himalaya, Himachal Pradesh, India

The slope instability in the Himalayan terrain is a common phenomenon which is caused by a combination of the ongoing seismicity and climate variability (extreme weather evets). In addition to this, in the last few decades, the anthropogenic intervention in the form of various developmental activity (roads, hydropower projects, expansion of urban sectors etc.) have posed serious threat to slope stability. In this study we have evaluated the terrain status for landslide susceptibility in a monsoon fed Giri Watershed. An attempted has been made to decouple various causative factors of landslides susceptibility of the region using remote sensing and GIS techniques. Employing the Frequency ratio and the information value methods, the study observe that increasing incidences of landslides occur along the drainage in the lower valley sides, along the linear developmental activities and settlement areas. Further the study observed a broad correlation between rock formation, lineaments, vegetation types, and slope steepness.