Landslides:
Landslides are common in the Himalayan hill roads. The main causes contributing to landslides are:
(a) Removal of lateral support at the bottom of a hill due to erosion by rivers.
(b) Earthquakes.
(c) Clearing of vegetation by cutting trees and grazing by cattle.
(d) Increased surcharge caused by rain or snow.
(e) Lack of drainage.
(f) Presence of faults and joints in the strata.
The measures for the correction of landslides include:
(a) Improvement in the surface drainage by constructing catchwater drains, side drains, cross-drainage structures and French drains.
(b) Afforestation and growth of vegetation by providing jute fabric and turfing.
(c) Prevention of grazing of animals by fencing.
(d) Provision of check walls, breast walls and toe walls.