Site specific landslide investigation using geospatial techniques A case study on selected landslides of Shimla and Mandi districts Himachal Pradesh India

Abstract

The research work focuses on detailed large scale mapping, Geological and Geo- Technical Investigation, slope stability assessment and stabilization measures of Dhalli and Jhakri Landslide, Shimla District, Himachal Pradesh and Kotropi Landslide, Mandi District, Himachal Pradesh. Dhalli landslide occurred on 2nd September, 2017 was a structurally controlled rock slide that occurred along a Road cut slope National highway (NH 5A) without proper toe support. Jhakri landslide is also located along the steep slope section of a National highway (NH-22) connecting Rampur and Jhakri area. Kotropi landslide occurred on August, 2017 along the Mandi Pathankot national highway (NH-154). The landslide is of complex type with deep seated failure with huge social and economic loss. Landslide susceptibility map (LSM) have been developed for the Dhalli, Jhakri and Kotropi landslide. The results reveal that for Dhalli landslide site 42.15% of the total area was covered in moderately vulnerable zone and 57.85% of the area is covered in High and very high vulnerable area. In Jhakri landslide site 100% of the total area was covered in Very High vulnerable zone. LSM of Kotropi study area reveal that 43.5% of the total area was covered in moderate vulnerable zone, 42.5% falls under high vulnerable zone and 15% falls under very high vulnerable zone. Large-scale mapping of the landslide sites Dhalli and Jhakri were conducted through total station. The results reveal that all the study areas are located along steep slopes of various National highways.