Experts recommend five areas for township for Wayanad landslides survivors
The five-member expert team headed by geologist John Mathai, investigating the landslides in Kerala’s Wayanad in which over 230 people were killed, recommended five areas suitable for townships for the survivors.
The five-member expert team headed by geologist John Mathai, investigating the landslides in Kerala’s Wayanad in which over 230 people were killed, recommended five areas suitable for townships for the survivors.
The experts submitted two reports.As per the government’s directions, the probe team examined the danger zones within the settlements of Chooralmala, Mundakkai and Punchirimattam, the most-affected landslide-hit areas, as well as the safety aspects of the areas identified by the government to build townships as part of the long-term rehabilitation of the survivors.
John Mathai, retired scientist of the National Centre for Earth Science Studies (NCESS), told HT, “We have submitted one report on the areas within the landslide-affected villages which can be classified as safe and where people can be relocated if the government wishes. We have drawn boundaries on the left and right banks of the Iruvazhinji river up till the Army-constructed Bailey bridge to show which are the safe and unsafe areas.”
“In the second report, we have assessed the safety aspects of the locations where the government is considering building townships for the survivors. There was a list of 24 places out of which the government itself eliminated many and finally arrived at 8 spots. Out of the eight spots that we assessed, we screened out three of them as they were unsuitable for large townships due to factors like limited area and steep slopes. In the remaining five locations, we have demarcated areas which are suitable to build townships. We have avoided steep slopes and slanted areas. All of them are close to Meppadi town, which is 13 kilometres from the landslide site,” he said.
At the same time, the expert team is yet to submit the main report on the causative factors that led to the massive landslides, the nature of the debris flow and its impact on the topography of the area. The team, said Mathai, hopes to visit the landslide-affected zones again in September as they were unable to conduct detailed examinations earlier this month due to inclement weather and paucity of time.
‘Damming effect’ likely caused massive debris flow
The preliminary assessment, however, is that a “damming effect” induced by extremely heavy rainfall caused the debris consisting of trees, boulders and large amounts of mud to flow down heavily over more than seven kilometres, flattening the human settlements below, Mathai said.
“During our inspection, when we traced the high water line of the Iruvazhinji river, we found that there were sudden dips in the water level in three places. One was upstream of Punchirimattam, the second at Punchirimattom and the third at Seethammakundu waterfall. In all these three places, the water level upstream was very high, but downstream at certain points, the water level was seen to fall by around 10-15 metres. This is what I consider to be the result of a damming effect,” Mathai added.
“The landslide event took place in a pristine forest area where there are a lot of tall and stout trees. These trees likely got uprooted and washed down. Below, in a narrow gorge like area, the trees along with boulders must have gotten stuck, forming a temporary dam. But due to continuous heavy rainfall, the water level must have risen and at a particular level, when it becomes unstable, it causes the dam-like structure to burst and break out. Once the dam bursts, it has enough energy to eat away both banks of the river and destroy all the houses in its path,” he underlined.
If not for the ‘damming effect’, the landslide’s impact would have been much less and the number of fatalities far lower, he said.
Mathai added the team found evidence of such ‘damming effect’ at least at three places. However, he stressed that this was only a preliminary analysis, which will need more evidence to substantiate.