In Wayanad, around five lakh tonnes of soil was displaced, most of it at one go
Over 100 people have died in the last seven days due to floods and landslides in Kerala, and the number of deaths is feared to climb as nearly 30 are still missing - most of them in Malappuram in the northern part of the state.
Kerala, according to data from the weather department, received 387 per cent excess rainfall between August 8 and 14. Wayanad district received 407 per cent excess rainfall for the same duration, while Malappuram received 500 per cent excess. This is in sharp contrast to around 35 per cent rainfall deficit in Kerala till end July, with reservoirs running dry.
In Wayanad, where one of the worst landslides took place, around five lakh tonnes of soil was displaced, most of it at one go, washing out an estimated 20 hectares of land, an official told NDTV. The death toll, in this Ecologically Sensitive Zone, would have been much higher, if many of the 56 families living there, were not evacuated a day before, say officials. 17 people have died in this particular landslide.
While experts agree that the immediate trigger for the major landslides in Malappuram and Wayanad was high intensity rainfall in a short span, research on 30 landslides by Kerala Forest Research Institute shows that at least 25 of them happened in what is referred to as "Ecologically Sensitive Zones". According to Kerala Chief Minister Pinarayi Vijayan, there were 64 landslides in the state in the recent disastrous spell. The two main landslide regions were also marked as low and high risk regions in the vulnerability map prepared by the National Centre For Earth Science Studies in early 2000s.
"We have observed soil piping in several places in Puthumala, and that could be one of the causes for the landslide here. Enmass deforestation that took place around 30 years ago, have left the roots of the trees decaying underground and leaving massive cavities in soil, further allowing for soil piping. In many places I have seen water gushing out of the soil, like pipes. To make things worse, the soil bed in this region is shallow with a depth of just around 1.5 metres. Land usage is a major concern", an official told NDTV.
Hume Centre For Ecology and Wildlife Biology has been analysing the 2018 floods and landslides in Wayanad for the District Disaster Management Authority. "For Wayanad, we have noticed three reasons. Intense high rainfall in short span, land fragmentation including mono cropping in some places, road construction and allied activities on hill slopes or adjoining them", Wayanad based ecologist CK Vishnudas told NDTV.
The Kerala Forest Research Institute data shows around 700 quarries in proximity of 50 metres to 10 kilometres near 30 landslide sites in Kerala, on Western Ghats. "Not all these quarries are necessarily functioning. Some could be dormant or abandoned. These figures are based on satellite images. But it's the proximity of these quarries to the landslide sites that also make it one of the causes in ecologically sensitive zones", Dr TV Sajeev, Principle Scientist at KFRI said.
In Wayanad landslide area of Puthumala specifically there were no quarries actively being used this year, with one of them being shut down last year. However, in Malappuram's Kavalappara area, the map showed around 20 quarries in proximity to the landslide. It isn't clear at this point, how many were functional. 20 bodies have been recovered from Kavalappara site.
Mr Vijayan clarified on Wednesday that temporarily stop memos have been issued for all quarry activities across the state, owning to the rainfall situation. The chief minister has also asked for village level mapping of vulnerable locations especially prone to landslides. "We have to study the locations, data and research to reach any conclusion", Mr Vijayan responded when asked about Western Ghats Ecology Expert Panel report.
Environmentalists across Kerala have been voicing their concerns on how paddylands have been reducing in Kerala. From 8.8 lakh hectares in 1970-71, in 2018 the state was left with an estimated 2 lakh hectares of paddyland. "We must remember the consequences of this. Paddylands, also doubles wetlands. As fallow lands, wetlands, it belongs to the waters. If there are none left, where will the excess water go?" environmentalist Jayakumar C said.
Unlike 2018, where around 400 people were killed, mostly due to floods, this year, majority of the 103 deaths have happened due to landslides.