Country’s first early warning system for landslides deployed in Darjeeling

Sagar Rai, a resident of Paglajhora in Darjeeling hills, has a rain-gauge installed in his village. Whenever there is a downpour, he runs to it and watches the level.

He has been trained to watch whether the reading exceeds 123 mm. If it does, he should stand before the gauge, forget everything else, and watch whether it approaches 143 mm.

The moment it is about to touch 143, he is supposed to send messages to a Whatsapp group that everybody should leave their homes immediately with their valuables and shift to designated safe places in the village.

Rai is not the only one. “On September 7, officials of Geological Survey of India held a mock drill and trained about 200 villagers from the three villages of Paglajhora, Giddapahar and 14 Mile to deploy the country’s first community-based early warning system for landslides,” said Dinesh Gupta, director general, GSI.

Besides sending messages in the Whatsapp group, village guards would blow whistles and ring bells in schools to alert villagers about possible landslides.

At least one member from each of the families in the three villages, and a number of officials from panchayat office bearers to the district magistrate and officials at the state and central level are included in the Whatsapp group so that they, too, are immediately alerted to take any administrative action if necessary.

“From panchayat pradhans to sub divisional officers, district magistrates to state officials, National Disaster Response Force to IMD officials, everybody would be alerted by a single message,” said Ladup Tamang, a resident of Giddhapahar.

Darjeeling, Kalimpong and adjoining Sikkim hills fall in seismic zone IV, and every year numerous landslides take place in these areas. In 2015, as many as 33 people died due to landslides in Darjeeling hills. The next year, the casualties stood at seven. In 2017 one person died and 291 people were affected in Darjeeling. Right now, a large part of North Sikkim is cut off due to landslides.

The Eastern Himalayas consist of young-fold mountains with higher slopes that receive more rains than the western Himalayas.

“In disaster situations, locals first respond and, therefore, GSI decided to put them at the centre of a system where are trained to monitor and interpret the surroundings for timely response,” said a GSI spokesperson.

The idea is to make the system work 24X7. The rain gauges have been placed in areas that are easily accessible. Two billboards detailing the procedure and action points have been put up in the villages.

“Stakeholder participation is a must to make every disaster management plan and action a success. The mountains in Darjeeling are the youngest ones and are always expanding and the area is prone to disaster. The area has the highest density of jhoras (streams) in the world. Local stakeholders should be trained properly,” said Tapas Ghatak, former GSI geo physicist and former UNICEF consultant for disaster management for Darjeeling hills.

Tuhin Ghosh, a faculty of Oceanographic Studies, Jadavpur University said, “People’s participation is of crucial importance in disseminating information, but the system needs continuous monitoring to serve the purpose.”

Since landslides can occur also due to tremors, GSI has also installed InSAR technology by putting five corner reflectors to monitor movement of the rocks and soil.

Satellite reflectors are commonly used to measure the movement of the earth as sensors are installed in the soil and rocks. They can work even in cloudy weather.

“Together the community members and the reflectors are supposed to keep a continuous watch on possible landslides,” said the GSI spokesperson.

“We hope to save life and valuables, if not houses,” remarked Gupta.

https://www.hindustantimes.com/