15% area around Mussoorie highly susceptible to landslides, say geologists

Tribune News Service

Chandigarh, August 31

About 15 per cent of the region around the popular tourist town of Mussoorie is highly susceptible to landslides, recently conducted geological surveys have revealed.

Like most hill townships, Mussoorie in Uttarakhand has witnessed several landslides, resulting from an increased spate of developmental activities.

The increased disaster hazard has led scientists to map the landslide susceptibility of the area.

Scientists from Wadia Institute of Himalayan Geology (WIHG) – an autonomous institute under the Department of Science and Technology – carried out the study in Mussoorie township and its surroundings covering 84 square km in the Lesser Himalayas.

The study could help initiate a large scale landslide hazard, risk, and vulnerability assessment of the hilly townships in different parts of India, the Ministry of Science and Technology said on Monday.

The scientists found that dominant part of the area falling under very high and high landslide susceptible zone lies in several settlement areas and popular spots like Kempty Falls.  These are covered by highly fractured Krol limestone exhibiting slope more than 60 degrees.

The Landslide Susceptibility Mapping (LSM) published in the Journal of Earth System Science also showed that about 29 per cent of the area falls in the moderate landslide susceptible zone and 56 per cent falls in low to very low landslide susceptible zone.

The researchers from the WIHG carried out the study using Geographic Information System (GIS) and high-resolution satellite imageries.

According to the researchers, various possible causative factors of landslides in the study area include lithology, landuse-landcover, slope, aspect, curvature, elevation, road-cut drainage, and lineament. 

The WIHG team obtained Landslide Occurrence Favourability Score (LOFS) for a particular class of the causal factor of landslide and subsequently calculated the weight of each factor of landslide to finally generate Landslide Susceptible Index (LSI) in GIS platform. This has been reclassified into five zones using natural break criteria.