‘Dam burst effect’ caused Wayanad landslide: experts
The Hindu
Geologists attribute Wayanad landslide to heavy rainfall, causing damming effect, wiping out villages; search for victims continues downstream.
A team of geologists who surveyed the landslide-hit zone in Wayanad on Thursday (August 15, 2024) said a heavy rainfall-induced “damming effect” in a densely forested and uninhabited uphill region had caused the massive earthfall that wiped out three villages at Vythiri taluk in the Wayanad district of Kerala early on July 30.
Geologist John Mathai, who heads the team of experts from the National Centre for Earth Science Studies (NCESC) investigating the landslide, told reporters at ground zero in Wayanad that the group’s finding was merely a “preliminary inference”.
More detailed studies were underway, including soil testing and gauging seismic stability.
Mr. Mathai said 570 mm of rainfall caused the forested hillock to get waterlogged. The saturated soil flowed downwards, forming a temporary “dam” at Seethammakundu.
The rain further boosted the scale of sodden topsoil discharge from uphill, straining the naturally formed dam and imperilling the slope’s stability.
Mr. Mathai said that in the early hours of July 30, the debris outflow stretched the naturally formed barrage to breaking point. It soon collapsed under the momentum of the unabating inflow of soggy mud and debris, including uprooted trees, triggering the hillock slippage that decimated the villages an estimated 6.5 km downhill from the landslide’s provenance.
Mr. Mathai said Puncharimattom, the origin of the landslide, was no longer habitable. However, a large swathe of land at Chooralmala could be reclaimed for the construction of houses. He said the NCESC team would soon submit its final report to the Kerala government.