Abstract:
Trimming of slopes as a consequence of proliferating economic growth and previously existing structures along anonymous unbalanced slopes has been one of the reasons for originating landslides along hillside areas. Numerous software packages are available to evaluate multiple 3-D failure surfaces seeking the lowest FOS e.g. CLARA (Hungr, 1988), 3D-SLOPE (Lam and Freudland, 1993) and so forth. Nevertheless, these software packages can replicate individual slopes or part of slopes and cannot capture the larger areas (regional). Although the potential of GIS for regional slope stability analysis is well recognized now, until date no specific delineation scheme to detect the unstable areas could be found in the literature. This study can serve as a guideline for better planning by the decision makers. The prime objective of generating Landslide susceptibility maps is achieved by coupling the deterministic slope stability model with GIS.
The study is divided into two criterions based on critical relief height and combined 3D-FOS. The decision making criterion considers 3D-FOS with respect to volume. The preliminary criterion of the delineation scheme can facilitate in finding regions with ground conditions differing from the adjacent area with explicit lithological and topographical characteristics taking into account the soil parameters as well. The secondary criterion based on 3D-FOS and volume of the possible critical slip surface takes into consideration the risk associated with the failure. The Susceptibility maps showing the hazard level will be valuable to identify the critical unstable zones and assist the policy makers for effective usage of resources in various paradigms for maintenance.