THIRUVANANTHAPURAM: Geological Survey of India (GSI) would launch the second phase of its comprehensive landslide mapping exercise in the state by the second week of October.
GSI, which is mapping landslide-prone areas in the country, had been studying the events in Kerala from the start of monsoon. However, considering the extent of damage due to landslide events during the recent rains, GSI has roped in more domain experts for the study in Kerala.
C Muraleedharan, deputy director general of GSI, said the first phase of landslide studies was carried out during June-July period. "Due to the scale of disasters that occurred in August, the state government had requested the organization to assess and evaluate causes.
A 15-member team comprising domain experts (landslide geologists), GSI officials and members of national disaster management authority had recently visited critical landslide spots in
Idukki district. "Inputs from state government, National Remote Sensing Centre and ISRO indicate that there were more than 2,000 landslide incidents reported in Idukki and Thrissur districts. More than 250 landslides have been reported in
Wayanad district alone," he said adding that shortage of landslide geologists has affected the speed of their work.
Several instances of cracks on the earth's surface were reported during the last monsoon. "It is suggested that all these cracks are filled with locally available soil and they should be properly compacted. To avoid the possibility of surface water entering these cracks, a layer of Bentonite clay has to be placed on the top of the compacted mass. People staying in the vicinity of these cracks should vacate the area when heavy rains are forecasted," said Muraleedharan.
The core activity of landslide division of GSI state unit is macro-scale landslide susceptibility mapping. This is being carried out under National Landslide Susceptibility Mapping - a project launched in 2014 in select areas of the
Western Ghats and its foothills. The project would help GSI detect unrecorded historic landslide data.
"We have completed 80% mapping in Kerala. In Idukki, we have identified around 1,600 landslide events in both revenue and forest land. Another 1,400 landslide events in Palakkad have also been identified. Our prime focus is to cover the revenue lands. Since it is a baseline data creation process it will take time. By 2020 we aim to identify and map the landslide-probable zones of the entire nation," said Sachin R, Superintending Geologist, GSI, state unit.
