Monitoring of Critical Himalayan Landslides and Design of Preventive Measures

Abstract

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.

Geological and geotechnical characterisation of the Khotila landslide in the Dharchula region, NE Kumaun Himalaya

“…It is estimated that after every 2 km, there is a chronic landslide in the Himalayan terrain (Valdiya 1980). Although triggered mainly by earthquakes or immense rainfall, the landslides in the Himalayan terrain are mainly caused by varying proportions of geological, geomorphological and geotechnical characteristics of slope, including the anthropogenic activities (Hewitt 1988; Bartarya and Valdiya 1989;Choubey et al 1992;Pachauri and Pant 1992;Gerrard 1994; Bartarya et al 1996;Panikkar and Subramanyan 1996;Sah and Mazari 1998;Sati et al 1998;Gupta et al 1999Gupta et al , 2016bRautela and Thakur 1999;Naithani et al 2002;Saha et al 2002;Gupta and Bist 2004;Neaupane and Achet 2004;Pant and Khayingshing 2005;Owen et al 2008;Anbalagan et al 2008;Dahal et al 2009;Anbarasu et al 2010;Kanungo et al 2013;Sharma and Singh 2013;Kumar et al 2014;Jamir et al 2017). As no two landslides are identical in their causes and triggering factors, it is therefore imperative to study each and every landslide to plan for its mitigation measures and strategies for the further development of the area.…”