Scientists on alert over soil piping in Idukki

THIRUVANANTHAPURAM: The new evidence of soil piping at Upputhura near Elappara in Idukki following the landslides on Tuesday has put scientists of the Centre for Earth Science Studies (CESS) and Hazard Vulnerability Risk Assessment Cell on alert. A team led by CESS senior scientist G Shankar and risk assessment cell head scientist Dr Sekhar L Kuriakose will investigate the new incidents next week.
The team had initiated the study of such incidents last year as part of a Rs 50-lakh project funded by the National Disaster Management Authority (NDMA). It is aimed at finding ways to stabilise the soil to prevent a disaster before it takes a toll on the lives of people in the region.
"In Upputhura, after the landslide, a fountain of water was seen coming out from a well-like structure. it's a clear incidence of soil piping and we are investigating it further next week," Shankar said, adding that such underground cavities are a case of land subsidence due to soil piping that can cause cracks in houses.
He said soil piping could also cause landslides, as in Wayanad at Thavinjal. "Water gushes in, resulting in sub-surface soil movement forming cavities. Soil piping keeps moving and growing; it is not static, it is cancerous. We expect more such incidents in Idukki, Wayanad and Kannur."
Earlier, soil piping was detected in Kannur at Thaliparamba and over 5,000 houses in Thirumeni and Pulingom villages of Cherupuzha are literally sitting on disaster with numerous soil pipes underground.
"Unless the exact reason for soil piping is identified, be it surface runoff or differential erosion, soil degradation due to leaching out, gravitational and thermal pressure variations, soil chemistry, we cannot prevent it from happening. Studying the reason will require deployment of technology or developing appropriate technology," Kuriakose said.
A detailed mapping was done in Pathanamthitta and efforts are now on to stabilise the soil by filling the underground cavities. This will require either geo-textiles or coir besides huge quantities of soil.