Monitoring of Critical Himalayan Landslides and Design of Preventive Measures

The entire Himalayan road network suffers extensive damage from a large number of landslides of different shapes and sizes. A large number of landslides on each highway have occurred repeatedly during every year for many decades, causing extensive risk to life of commuters, loss of revenue from direct and indirect losses and hardship for the people, thus influencing the socio-economic conditions of the region. One of the important highways of the country, which connects the north western Himalayan state of Uttarakhand to rest of the country, suffers from large numbers of such landslides. Two of the most critical landslides have been selected as pacesetter examples for investigation, monitoring and prevention. These two landslides have been monitored using a very simple system consisting of specially designed grooved steel pedestals, total station and DGPS (Differential Global Positioning System). The results of monitoring have encouraged utilising the same system for other Himalayan landslides of a recurring nature instead of investing in heavy-duty, costly and sophisticated instrumentation. This paper gives a detailed account of two landslides and the monitoring processes followed in a scheme of remedial measures for their long-term prevention.