Kerala landslips | On shaky ground

Landslips in rain-soaked mountains of Kerala have a human angle. And like much of the world, it is also forcing the State to reckon with the everyday impact of climate change

September 15, 2022 08:30 pm | Updated September 16, 2022 05:47 pm IST

Danger zone: (from left) A view of the Adoormala hillside where a landslip struck last month

Danger zone: (from left) A view of the Adoormala hillside where a landslip struck last month | Photo Credit: The Hindu

Only a vantage view of the hill captures the true scale of the horror. A wide, sludgy scar runs down its sideways, revealing the trail that the dislodged rocks and soil took to bury alive a five-member family living there.

In the closely packed colony of Maliyekkal on the Adoormala, a wash of mud and rubble travelled faster than screams during the early hours of August 29 . Ashokan Naramangalath, a local resident was in his bedroom when he heard the commotion around 3.30 a.m. It sounded as if the land was opening up and the ground shook.

He rushed outside for a better view and followed the dirt path to his neighbourhood, only to see a pile of dark-brown debris where a house had stood for years. The house belonged to Chittadikkal Soman, a 55-year-old, who had lived there along with his mother, wife, daughter, and grandson.

“An avalanche of mud arrived with such force that it destroyed everything on its path and deposited them far below at the base,” he says.

Search and rescue personnel navigated through heavy rain and mud-caked roads to reach the spot and recover all five bodies. A team of geologists, which assessed the site, reported to the District Collector that the area was prone to landslips, especially in the event of extreme rainfall.

The episode, triggered by the extreme rainfall the previous night, was the latest in a series of landslips and mudslides that have wrecked Kerala back-to-back since 2018. And once again, it has made starkly clear how defenceless the State’s high-range communities are in an era of destabilising climate.

According to experts, landslips in rain-soaked mountains of Kerala have a human angle. And like much of the world, it is also forcing the State to reckon with the everyday impact of climate change.

Unscientific land use

Rapid Action Force (RAF) and Kerala Fire and Rescue personnel during rescue operations at the site of landslide at Koottikkal in Kottayam district

Rapid Action Force (RAF) and Kerala Fire and Rescue personnel during rescue operations at the site of landslide at Koottikkal in Kottayam district | Photo Credit: Vishnu Prathapn

As per a recent study led by K.S. Sajin Kumar, member of the Kerala Landslide Expert Committee, in association with the Kerala State Disaster Management Authority, unscientific land use practices along with the changing climate and geomorphic factors triggered the landslips that devastated Koottikkal, Kokkayar, and Plappally last year.

It points out that the steep slopes of all the three villages, located in the same valley and originally contained natural contiguous forests, are now dominated by human interventions in the form of plantations and human settlements. The study also took note of the anomalous rainfall event of 266 mm on October 16, which triggered the landslips.

Also read: Study on landslip-hit locations in Kerala highlights need to research rainfall dynamics

“The extreme rainfall events, turbocharged by climate change, are far too complex for precise disaster forecast. So the vital feature to be researched is the rainfall dynamics, which can be converted into early warning systems,” says Mr. Kumar.

The communities that have clustered together in the high ranges have always suffered disproportionately during natural disasters. But as rains increase in ferocity, scientists expect them to become even more vulnerable

A primary analysis of the landslips that have struck Kerala since 2018 shows an uneven geographic distribution, pointing to the fact that many parts of the Western Ghats are susceptible to landslips.

Also read: Regional land use planning can be started in Kerala to reduce the risk of landslides: GSI Geology director

“At least 10,000 square kilometre area across the rain-soaked mountain ranges in 13 districts are prone to landslips,” says C. Muraleedharan, former deputy director general of the Geological Survey of India, and chairman, advisory committee for landslips and risk reduction under the KSDMA.

According to him, what the rains effectively do is to reduce the strength of the soil. It thus reaches a point where it fails and naturally just slides away. More rain, on its own, increase the landslip risk but that risk is amplified by unscientific interventions such as contour-bunding of rubber plantations or other constructions, which ignores the natural flow of water.

Rubber plantations

A rubber plantation in Kerala

A rubber plantation in Kerala | Photo Credit: H VIBHU

“Rubber plantations are particularly problematic as the trees possess no deep roots. Activities such as slaughtering of trees that lays an entire hillside bare or the digging of rain pits only compound the situation,” he says.

Villages that abut the rocky hills are susceptible to reshaping of slopes through stone quarrying. “The waves induced by stone blasting too can be a trigger. As per studies, such waves only propagate up to a distance of 50 metres. This means quarrying operations may lead to landslips only in their immediate vicinity,” says Mr. Muraleedharan.

GSI’s risk analysis

The Geological Survey of India (GSI) has conducted a risk analysis of the State’s high ranges, the results of which will soon be released. “We are working on a comprehensive mitigation strategy. The current focus shall be to identify the potential failing points and thus contain the damages,” says Saibal Ghosh, Director (Geology), Geohazard Research and Management Centre, GSI.

Policymakers argue that one more factor, divorced from climate, is making these dangers all the more pressing to address: the infrastructure-oriented development on the hills.

Regime reversal

“Instead of intervening in the jumble of forecasts and analysis, what we need is a reversal of this regime and a re-clustering of its population in safe locations. They should, at the same time, be permitted to retain their land for agriculture,” says Shekhar L, Kuriakose, member secretary, KSDMA.

According to him, about 4,500 families from the vulnerable locations have been relocated to safer areas under a project by the State government. But with as many numbers of families left to be relocated, the State alone will not be in a position to mobilise the resources and complete the mission in a time-bound manner.

Also read: Tribal families reluctant to relocate despite natural calamity threat

Mr. Kuriakose also highlights the need to re-cluster people from the downstream stretches of the areas marked vulnerable to landslips. In most of the fatal landslips , including at Puthumala in Wayanad and Pettimudi in Idukki, the point where the earth actually slipped is far away from the point where it struck.

“We have got a long way to go to be able to predict what any given landslip is going to do. But for the time being, we should keep the people at a safe distance from these points. Just in case,” he says.

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