According to recent news by TOI, almost three years back the Geological Survey of India (GSI) has started the process of mapping landslide-prone zones in the Nilgiris (Western Ghats of India), which has reached its final stages and will be completed in next four months. According to GSI, around 0.09million sqkm of the Western Ghats spread across Tamil Nadu, Andhra Pradesh, Kerala and Karnataka are landslide-prone areas.
The complete map is likely to be submitted before the Nilgiris district collectorate in the , said senior officials attached to the Geological Survey of India (GSI).
“The field officer has completed the survey and study in Kallar, Coonoor, Kotagiri and Ooty, covering around 80% of the district,” said a senior director, who did not want to be named. “The western and north-western portion of the Nilgiris, including Gudalur, is being studied now,” he said.
GSI began studying Nilgiris and Kodaikanal in Dindigul district around three years ago. “We chose these places as they are heavily populated and also tourist spots, and in the event of the landslide, the loss will be huge,” the official said.
The marking of landslide-prone zones is being done manually. Remote sensing techniques were used to predict earthquakes, for landslides the process was manual.
Officials said a major cause of landslide was construction and infrastructure development on the slopes. “This activity includes clearing of vegetation, heavy construction of slopes and often removing a natural way for rainwater to drain. As a result, the rainwater permeates into the pores of the soil, loosening it, and also starts seeping out through a small crevice under heavy rocks,” the official said. “When this happens, often the entire rock is brought down by the rainwater’s pressure causing an avalanche,” he added.