Explained: How Idukki landslide took place after state received heavy rainfall

Idukki, Aug 11: The tragic landslide, that took place on August 6 at 10:45 pm at Pettimudi, a hamlet in Rajamala ward under Munnar village panchayat in Kerala's Idukki district. Kanan Devan Hills Plantations Company (P) Ltd workers were living in Pettimudi. Rajamala includes Eravikulam National Park, and the landslide was triggered from a shola forest region in the national park.

The horror of rocks, slurry and sludge came crashed down a distance of around 2 km to a patch of valley in Pettimudi, crushing the single-room houses of estate workers that stood in two rows.

It can be seen that the location, where the landslide was triggered, has a 40 degree slope, and any slope above 20 degree is vulnerable to slipping during heavy rain. Also, the soil has a high content of sand, which takes room for more water and the risk of slipping down.

An analysis of landslides in Idukki by the State Disaster Management Authority has shown that high-intensity rainfall saturates the soil on the slopes. Soil with higher clay content has high water retention capacity and low drainage capacity.

It also has to be noted that human interventions, such as heavy loading on the slopes caused by buildings on cut-and-fill ground, without required protective measures on the uphill and downhill sides, have made the area particularly vulnerable.

The victims of the tragic incident

Accoridng to officials, as many as 83 people were living in 30 single-room, sheet-roofed quarters, provided by the estate. 12 of them were allegedly rescued by residents of another settlement. So far, the officials have recovered 49 bodies in laborious rescue operations.

According to locals, more are missing as many had come as guests from other areas. The victims included 31 persons of one extended family who lived in adjacent quarters, and six temporary staff at the Eravikulam National Park. As many as 19 school children have been missing.

In 2018, invarious landslides in Idukki claimed 60 lives. Elsewhere, a landslide in Thamarassery, Kozhikode killed 14, and another in Kurancheri, Thrissur killed 1. In 2019, 59 persons died in Kavalappara, Malappuram. In Puthumala, Wayanad, another landslide killed 17.