Landslide hazard analysis of the area around Dehra Dun and Mussoorie, Uttar Pradesh

• Published in: Current science (Bangalore) Vol. 73; no. 12; pp. 1117 - 1123
• Main Authors: Panikkar, Sambhu V., Subramanyan, V.
• Format: Journal Article
• Language: English
• Published: Current Science Association 25.12.1997
• Subjects: Drainage structures; Forest cover; Geological hazards; Gravel; Hills; Landslides; Natural hazards; Quartzite; RESEARCH COMMUNICATIONS; Riverbanks; Slates
• ISSN: 0011-3891

Landslides are a common natural hazard in mountainous terrain like the Himalaya. In the present study, an area of 445 sq km around Dehra Dun and Mussoorie in Uttar Pradesh has been considered for landslide hazard analysis on a geomorphological basis. The analysis involves classification of the terrain into homogeneous units (terrain mapping subunits) based on relevant geomorphic parameters, and consequently the geomorphic processes including occurrence of landslides. The hazard in these units is evaluated on the basis of field settings. Decision rules for the allotment of a hazard score to a unit have also been framed. The data on geomorphological complexes, lithology, drainage density, relief and landslide distribution were used in a geographical information system (GIS) for the analysis. A final landslide hazard map with four classes – very high, high, low and very low has been prepared. Such a map proves extremely useful as a first generation map for planning detailed surveys in the high hazard areas. The effect of human interference on the environment, particularly depletion of the forest cover has been studied. The landuse/land cover data for a period of 60 years were analysed in a GIS to study the changes in the forest cover. The forested areas account only for 9% of the landslide occurrence. About 60% of the landslides are in non-forested areas that were forested in 1930.