Unchecked, unscientific construction led to landslides in Idukki, say experts

Some parts of Idukki are still isolated due to the landslides, and vehicular movement in the region is still restricted.
Unchecked, unscientific construction led to landslides in Idukki, say experts
Unchecked, unscientific construction led to landslides in Idukki, say experts
Written by:

This monsoon season, Idukki saw 278 landslides, which claimed 46 lives and destroyed more than 100 acres of property. In fact, until now, parts of Idukki are still isolated and roads haven’t been fully opened yet. The landslides have also affected connectivity to various tourism destinations in Idukki. It has also created a huge revenue loss in the tourism sector in Munnar and Thekkady, as thousands of tourists were expected to arrive to see the Neelakurinji bloom.

The people of the district are still reeling under the effects of the disaster. But what if this disaster in Idukki was entirely manmade?

A report prepared in 2017 by Dr Sajinkumar KS, assistant professor, Kerala University, and Dr Thomas Oomen , professor at Michigan Technical University, says that the recurrent landslides seen in the region are manmade.

An example cited by them is the landslide that hit the Government Arts College, Munnar, in 2005. In a paper submitted to the Geological Society of India, he had written that the landslide fell under the category of a hardward retreat. He said it was so as there was the potential that the ‘crown’ could lead to another landslide. And this was precisely what happened in 2018, when the crown collapsed and a landslide occurred once again.

The report published in 2017 also detailed how 60% of the areas in Idukki were landslide-prone, and Thodupuzha is least likely to see landslides. It also said that after Idukki, Wayanad was the second-most landslide-prone region in the state, while Alappuzha was likely to see the least number of landslides in the state.

Landslides in Idukki's Paniyarkutty

“In general, the factors influencing landslides are classified as conditioning and triggering factors,” Dr Sajinkumar tells TNM. “Conditioning factors usually have to do with the terrain, such as the soil, geology, land use, drainage, groundwater, etc. Triggering factors are the direct causes of landslides – rainfall, earthquakes and anthropogenic activities.”

According to him, in Idukki, the loose soil rests on hard rock without adhesion, which leads to the landslides.

"Munnar in Idukki district geomorphologically differs from the rest of the district for it is a plateau. This geomorphic unit, together with the prevalence of tropical climate, permits the formation of a thick column of soil. The second-most important conditioning factor in Idukki is the steep slope. Slopes at a 15-degree angle are prone to landslides. As the slope angle increases, the stress on the soil or other unconsolidated material tends to increase, and such areas will see a high frequency of landslides,” he explains.  

In Munnar, he tells us, the cause was human interference.

“We have to check the status of Munnar, but most landslides occurred due to unscientific construction,” says PK Shaji, the tahsildar of Devikulam.

A history of landslides

 If we look back at the history of Idukki, the region has seen several devastating landslides since 1958. As per available records, about 177 people have died due to landslides in the region.

The major landslides that the region saw include the one on August 2, 1958, at Thodupuzha, which killed 24 people; the landslide in Adimali on 26 July, 1977, that killed 33 people; the 21 July, 1997 landslide at Pazhampillychal, Anaviratty and Irumbupalam, that saw a toll of 22; Koompanpara landslide of 22 July, 1989, that took 18 lives and at Adimali on 3 November, 1989, that killed 10 people.

Landslides in 2018

The monsoons this year saw 19 major landslides in the region, which claimed 46 lives.

 "Unscientific construction of homes and buildings in the water sources are the main reasons for the landslides in this hilly district. The construction activities on cliffs, the unscientific trenching to lay cables in the roads and the illegal construction of roads in the hills have caused the landslides," says a source in the Revenue Department.

A caved-in road in Munnar.

CS Dharmaraj, an environmentalist from Wayanad says, “Officials evicted the people from landslide-prone areas in Wayanad so lives were saved. But hundreds of acres land was destroyed due to the landslides. The quarries and illegal constructions in the hills and valleys are the main reason the district saw such destruction."

 A landslides wiped out George Karakomban’s six acres of land in Kallarkutty, near Adimali. “In addition to my fish tank and cattle shed, six cows were washed away in the rains and landslides. Farming is my main source of income and I don’t know how I will survive,” he says.

According to Dr Sajinkumar, modelling landslides by analysing the rainfall threshold could be the simplest, most cost-effective and comprehensible early warning system for shallow landslides in Idukki.

"Such an early warning system can be developed on a site-specific basis, and may be generalized for regions that have similar climatological and topographical conditions," he adds.

In the wake of the heavy landslides and mudslide in the hilly areas, the government has temporarily banned construction activities in the ecologically fragile areas in the state. But, according to the residents of Idukki, the decision will affect them as most of their houses are partially damaged. "What will we do when we return home from the camps? Can we stay in the damaged homes without renovating it?" they ask.

This article has been produced in partnership with Oxfam India. In the last 10 years, Oxfam India has delivered over 36 impactful humanitarian responses in India.Oxfam India is providing critical relief to the affected families and communities in Kerala: clean drinking water, sanitation, and shelter kits. Click here to help #RebuildKerala.

Related Stories

No stories found.
The News Minute