The Geological Survey of India (GSI) has recommended shifting of the housing lines from the flanks of the streamlets at Pettimudy as there is uncertainty over the prevailing conditions in the scarp area that triggered the landslip on August 7.
No new constructions should be allowed in the mouth area or close to the stream flanks, says a report submitted to the District Collector.
The inhabitations on the hill slope of Pettimudy should be kept at a safe distance. The incessant and high intensity rainfall on continuous days was assessed as the triggering factor of the Pettimudy landslip.
“The incessant and high intensity rainfall on the preceding days is assessed as the triggering factor. It is inferred from the site conditions that the instability in the slope has been induced by reduction of strength on super saturation and increase in pore water pressure of the overburden material. The steep slope of the terrain and nature and thickness of the overburden material are the major factors owed to this,” the report says.
The report recommends that human inhabited areas should be kept at a safe distance from the streamlets and also from the main river so that the risk from slope failures as well as flooding can be avoided.
The GSI also recommends precautionary measures while undertaking construction work of the road to Edamalakkudy through Pettimudy.
District geologist Biju Sebastian told The Hindu that that the landslip at Pettimudy was not human-induced and it pointed out how the areas that were not listed as landslip-prone could turn sensitive to natural calamities.
There was a landslip on the opposite side of the same hill in the forest at Pettimudy. However, it did not come to public notice. There should be early warning systems on the human inhabited slope areas and measures to shift people to safer areas in case of extremely heavy rainfall, he added.