Landslide is a physical phenomenon when a part of rock, and/or debris/ soil fall due to the action of gravity. It is caused by a set of terrain-specific geofactors (e.g., slope, lithology, rock structure, land use/ cover, geomorphology etc.) and in general is triggered by heavy rainfall or earthquake tremors. In Indian terrain, landslide events are mostly triggered by monsoonal rainfall but examples of earthquake-triggered landslide is also not uncommon in India (e.g., Uttarkashi Earthquake, Chamoli Earthquake, Sikkim Earthquake etc).

The entire Himalayan tract, hills/ mountains in sub-Himalayan terrains of North-east India, Western Ghats, the Nilgiris in Tamil Nadu Konkan areas are landslide-prone (~ 0.42 Million Sq. Km.; including the permafrost regions it becomes 0.49 Million Sq. Km).

Each landslide has specific spatial and temporal attributes. GIS is the only tool through which its spatial, temporal, and other attributes can be linked and kept in a georeferenced spatial database. Landslides are also of varied types, involving different types of material, different types of movement etc. Apart from the above, a lot of spatially-associated attributes about its causal geofactors can also be observed which can be linked to a landslide incidence. All the above information in such a georeferenced spatial database (e.g., GIS) can exhibit the landslide inventory of an area.

Techniques to predict spatial locations of future landslide occurrences. That mean it answers where a future landslide can occur. This requires prior knowledge about the landslides that occurred in any area.

Landslide studies entail a holistic process, beginning with the identification of landslide-related issues, followed by rigorous assessments of susceptibility, hazard, and risk. These assessments involve sophisticated predictions of spatial distribution, temporal occurrence, and magnitude, culminating in comprehensive loss estimations. Subsequently, thorough risk evaluations are conducted, leading to the formulation and implementation of targeted ground-level strategies aimed at mitigating the identified risks effectively.

Techniques to predict or estimate monetary losses caused to an element-at-risk (roads, buildings) or estimation of losses to human lives due to any landslide hazard. This is the ultimate aim of any landslide hazard studies and mostly be useful to planners and insurance agencies. However, the above analysis is extremely difficult due to non-availability of both spatial and temporal information of landslide occurrences. Like many landslide-prone countries, India is also having the similar problems. That is why landslide hazard and risk analysis in truest sense are rare in India. To remedy the above and to prepare a dynamic, and spatially-distributed national landslide repository, the Web-based National Landslide Incidence Inventory project of GSI has been taken up which will ultimately prepare a comprehensive nation-wide landslide database.

Techniques to predict both spatially and temporally the locations of future landslide occurrences of certain magnitudes. This means that this predictive analysis answers where, when and how large the future landslide could be. For landslide hazard analysis, availability of historical information on past landslides is essential.

Scientifically GSI's main role or position in the Landslide Management Framework is as follows.