MEPPADI (WAYANAD): A post-disaster analysis by an official team that included experts from soil conservation department at Puthumala found that felling of a large number of trees during late 1980s and the recent cardamom farming might have caused the massive landslide on August 8. The officials will submit a detailed report to the district collector on Tuesday.
Agreeing with the official finding, Meppadi panchayat president KK Sahad said the extensive felling of trees during 80s could be the reason for the massive landslide. The investigation conducted atop the mountain after the landslide found that the topsoil depth was only 1.5 metre and the high-intensity rain from August 4 resulted in water seeping into the cavities which were formed when roots of the felled trees decayed over the years.
“Over the years, million litres of water got stored in the soil making it soft and unstable. Gradually, the soil started loosing its grip and the rocks in between also became loose. As more water got absorbed, the pressure increased on the rocks which gave away. The force was so huge that one cubic metre of area came down with a weight of one tonne,” said Wayanad Soil Conservator Officer P U Das.
He said the recent trend of cardamom farming on the side of the mountain also made the soil loose. “The soil was tilled and softened for cardamom farming. This is not at all recommended.” He said the land use pattern must be changed to prevent repeat of the landslides.
The epicentre of the landside was 290 metre high on the mountain and it brought down 20 hectares of land pushing it to a distance of about 2 km. “The government must do a detailed study to further ascertain the reasons (behind the calamity),” the officer said.
What are the warning signs of an impending landslide?
High intensity rain for a day is enough to cause a major landslide in the hilly region. Before a major slide, several small landslips will occur in different parts of the hill. There will be unusual sounds, mainly loud thudding.
With soil giving away for water to gush out, new streams will develop.
Long-time residents of the area will be able to identify certain geographical changes like a few trees slanting to one side etc.
Intense rainfall
An analysis of the rainfall showed that in the span of just 24 hours before the landslide, the area received 51 cm of intense rain.