Most landslides in Manipur caused by anthropogenic factors: Environment ministry

Every year, during monsoon, landslides claim a number of lives and cause huge damage to property across the country, especially in the hilly region, and this time it was no different.

Recently, landslides in rain-battered Kerala left a trail of destruction, while in Manipur, a massive landslip killed nine people last month. The northeastern state has witnessed six major landslides since May.

The hill state of Himanchal Pradesh was also hit and in Uttarakhand, a number of pilgrims during the Kailash Mansarovar and the Kanwar yatras were left stranded due to landslides.

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Specifically for Manipur, the Environment Ministry has indicated that most landslides in the state were "anthropogenically" induced and were caused due to a host of reasons, including modification of slopes for construction and widening of roads. Experts stressed that there was an urgent need to clearly classify high-landslide prone regions and to update the reviews every decade.

Manipur witnessed six massive landslides in 2018, three in 2017, one in 2015 and four in 2010, according to the data provided by the ministry for the state. Triggered by heavy rains, a massive landslide claimed nine lives in Manipur's Tamenglong district on July 11. "Landslides in environmentally sensitive hilly areas of Manipur occur frequently during monsoon in the state.

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"Studies have indicated that landslides in Manipur are mostly anthropogenically induced, caused as a result of modification of slopes for construction, widening of road, quarrying for the construction materials, fragile lithology, complex geological structures and heavy rainfall," Minister of State for Environment Mahesh Sharma said in the Rajya Sabha on August 6. The weathered sedimentary (shale) rocks of Disang formation and thick loose overburden deposits on valley dipping slopes are most vulnerable for landslides in Manipur, he said in a written reply.

The six massive landslides in Manipur this year occurred in Tamenglong in July, on NH-102 in East Imphal, NH 37 in Noney district, NH-102A in Ukhrul district and NH-37 in Noney district in June and on NH-37 near Makru bridge in Tamenglong district in May, according to the ministry's data.

Experts also stressed on the need to understand that deforestation, blasting, tunnelling and encroachments on drainage systems among others increase the potential for landslides. In his reply, Sharma had also said that the government promotes and supports research studies relating to landslides with remote sensing and Geographic Information System (GIS)-based mapping for proper management of landslide-sensitive zones. He pointed out that GSI was actively engaged in carrying out landslide inventory mapping, national landslide susceptibility mapping (NLSM) on a 1:50,000 scale and 1:5,000 scale, and site specific study of a landslide, including monitoring, to minimize environmental degradation. "These landslide studies are carried out as per the laid-down framework of Standard Operating Procedures (SOPs) for Landslide Disaster Management Plan of the GSI," he said.

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In addition, the National Disaster Management Authority (NDMA) under the Home Ministry has conceptualised an umbrella pilot scheme- Landslide Risk Mitigation Scheme(LRMS)- to demonstrate benefits of landslide mitigation measures under a centre-sponsored scheme for providing financial support to states, including Manipur, for disaster preparedness and mitigation, the minister said.

Talking to PTI, an expert in this field pointed out that there is a need to realise that the entire Himalayan region and some hilly areas in the Western Ghats and elsewhere are inherently landslide prone. "We need to clearly classify such highly landslide regions and also update the reviews, say every decade or so. Secondly, we should understand what increases the landslide potential.

"Deforestation, blasting, tunnelling, encroachments on drainage systems, including rivers and streams, on the hill slides, etc definitely increase the landslide potential," Himanshu Thakkar of the South Asia Network on Dams, Rivers and People (SANDRP), said. The impact should be assessed whenever any major interventions, in terms of roads, dams, hydropower projects, tunnels, blasting, deforestation, mining, are made in the landslide prone areas, he said.

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Such impact assessments would then have management plans to deal with such increased potential for landslides, he said, adding, "it can then include some cases where you abandon the proposed project." "Or in others, like in case of Uttarakhand, where the state disaster mitigation and management centre recommended in 2012 (before the June 2013 Uttarakhand floods) that no blasting should be allowed in Uttarakhand for any development activity. "Lastly, we also need to understand that landslides are also associated with other disasters like floods, flash floods, earthquakes, among others," he said.

The assessment then should include the possibility of multiple disasters associated with landslips, Thakkar added.