Kannur to get Kerala's first landslide warning system capable of alerting a day in advance

Kannur: Kerala is set to get its first landslide early warning system capable of predicting slope failures at least 24 hours in advance, giving authorities enough time to evacuate people from vulnerable areas before disaster strikes.

The pilot project is coming up at Madassery Hill in Kanichar grama panchayat, on the Kannur-Wayanad route. The panchayat, near the Aralam Wildlife Sanctuary, witnessed around 34 landslides in 2022, making it one of Kerala's most landslide-prone regions.

"The minimum lead time we can provide is about 24 hours because the prediction is linked to the India Meteorological Department's rainfall forecasts," said Dr Debi Prasanna Kanungo, Chief Scientist and Professor at the Geotechnical Engineering and Geohazards Division of the CSIR-Central Building Research Institute (CBRI), Roorkee, who is leading the scientific work. "Once the warning threshold is crossed, the government can evacuate people living in the vulnerable area before the landslide occurs," he told Onmanorama.

The nearly ₹2-crore project is being implemented jointly by the Kerala State Disaster Management Authority (KSDMA), the Kerala Development and Innovation Strategic Council (K-DISC) and CBRI, a CSIR institute located on the IIT Roorkee campus in Uttarakhand.

A weather monitoring station was installed at the site in January as the first phase of the project. The next stage involves drilling boreholes and installing sensors 15 to 20 metres underground at eight locations from the top of the hill to its base.

Before the sensors are installed, scientists carry out geological and geophysical surveys to map the underground layers of soil and rock. The system then continuously monitors rainfall, soil moisture, underground water pressure and even tiny movements within the slope using specialised sensors developed by IIT Roorkee.

The data collected during the first monsoon is used to determine the rainfall threshold at which the slope becomes unstable. That threshold is then combined with IMD's rainfall forecasts. If the forecast indicates rain intense enough to push the slope beyond the danger limit, the system automatically issues an alert.

"The triggering factor for most landslides in Kerala is rainfall," Dr Kanungo said. "We first establish how rainfall changes soil moisture, underground water pressure and ground movement. Once those thresholds are scientifically established, we integrate them with the IMD forecast to predict landslides."

Warnings can be issued through sirens, display boards and mobile phones. Even if mobile connectivity fails during extreme weather, a node coordinator installed at the site can independently analyse the sensor data and trigger alerts.

"If high-risk slopes are identified in advance and monitored continuously, authorities can evacuate people whenever the warning threshold is crossed," he said.

To conserve power, the sensors remain in sleep mode during normal weather and automatically switch to high-frequency monitoring during heavy rainfall or whenever they detect changes in soil moisture, water pressure or ground movement.

Officials said the Madassery installation will also help assess landslide risks in nearby areas with similar geological conditions. If the pilot project proves successful, the technology will be expanded to other landslide-prone regions of Kerala, including Wayanad.

According to Dr Kanungo, the landslide early warning system has already been installed at vulnerable sites in Uttarakhand and Nagaland, while similar projects are currently being implemented in Kerala, Darjeeling and Sikkim.