New warning technology for landslide hotspot in India
August 8, 2018 - Chandmari, Sikkim, India
The Sikkim-Darjeeling belt is at the highest risk of landslides in India and is a top location globally, according to the United Nations Office for Disaster Risk Reduction. Amrita Vishwa Vidyapeetham is installing a real-time landslide detection system in the North Eastern area of the Himalayas. The project is jointly funded with the Ministry of Earth Sciences, Government of India.
The technology guards against rainfall-induced landslides. Not only is tectonic activity higher in the southern Himalayan arc, monsoon rains and man-made changes to the slopes have made these hills much more prone to landslides.
Globally, landslides kill more than 4,000 people per year. “Landslides are the third most deadly natural disaster on Earth,” explained Dr. Maneesha Sudheer, Director of The Center for Wireless Networks & Applications.
“The number of fatal landslides in India is higher compared to other countries. A report by Indian Roads Congress estimates that 15% of India’s landmass is prone to landslide hazard.”
The network in Sikkim will be Amrita Vishwa Vidyapeetham’s second one. Its first is in Kerala’s Western Ghats and has issued several successful warnings since installation in 2009. The wireless sensor-based system is considered more accurate than the rainfall threshold model commonly used.
The system collects continuous data from the sensors, performs basic analysis at the Field Management Center in Sikkim, and then relays that information to the Data Management Center at Amrita Vishwa Vidyapeetham in Kerala.
The university researchers are using this data to characterize and learn the geological and hydrological nature and response of the hill with respect to the dynamic and real-time meteorological variations. In this way, they will develop an early warning model for landslides in that area.
In Sikkim, the warning unit consists of over 200 sensors that can measure geophysical and hydrological parameters like rainfall, pore pressure and seismic activity. It will monitor an area spanning 150 acres around Chandmari, a densely populated village in Sikkim’s Gangtok District. This area has already experienced landslides with the first one reported in 1997.
Landslides can be triggered by natural causes like vibrations from earthquakes and the build-up of water pressure between soil layers due to prolonged rainfall or seepage.
In recent decades, man-made causes have also become significant in contributing to the triggering of landslides. This includes removal of vegetation from the slopes; interference with natural drainage; leaking water or sewage pipes; modification of slopes by construction of roads, railways, buildings, etc.; overloading slopes; and vibrations from traffic.
According to Dr. Sudheer, several steps can be taken to reduce fatalities due to landslides.
“In the case of landslides, forewarned is forearmed. More accurate landslide databases need to be maintained and regional as well as site-specific rainfall threshold models developed,” she said.
“Low-cost, in-situ monitoring technologies have to be deployed in landslide prone terrains. People have to be educated regarding landslides and the risks involved."