Drones become a lifeline in Nepal's flood response
In the flood-ravaged hills of Nepal, drones are taking on an expanding role in disaster response, from ferrying food and medicines to cut-off communities to airlifting bodies from areas too dangerous for rescuers to reach. This week, seven bodies were flown by drones from Devighat-3 in Nuwakot to Devighat-5, an area so difficult and dangerous to navigate that rescuers could not safely reach it, according to a report published by The Kathmandu Post on Wednesday. The report described the operation as "perhaps their most unusual role yet."
The drone team included personnel from Nepal Police, the Nepal Army, and drone manufacturing company GarudX. The use of unmanned aerial vehicles (UAVs) is becoming an important part of Nepal's disaster response as roads and bridges are washed away and swollen rivers cut off communities from one another.
In Devighat-3, one of the worst-hit areas, an AI-enabled drone flew over stranded villagers, its loudspeaker asking them a series of simple questions: Do you have water? Food? Medicine? Villagers were asked to raise their hands in response. "Based on the villagers' response, we make an assessment for what they require and send the delivery through drones," Milan Pandey, director of Airlift Technology and a drone pilot, was quoted as saying by the Post report. The drone also asked people to provide a phone number or address, which could be written on a placard or even in the mud, allowing operators to identify their location and requirements.
Pandey said his company supplied at least 1.5 tonnes of emergency supplies, including food, to the affected areas in three days. The system has particular value in a disaster like the recent floods, where roads and bridges have been washed away and communities separated by swollen rivers can no longer reach one another.
The challenge of hydropower tunnels
While drones have proven effective in open areas, the search for hundreds of workers believed to be trapped in power plant tunnels presents an entirely different challenge. At the Upper Trishuli-1 hydropower project, a drone was flown inside a tunnel where scores of workers are believed to have been trapped following the floods, the report said. "We reached platform 1 of the project and saw the tunnel filled with water and rocks. It's risky and challenging to get inside," said drone operator Adarsha Bhusal. The drone found no signs of life inside the tunnel, he said.
Drone pilot and filmmaker Manish Maharjan, who joined the Nepal Army's rescue efforts a day after the Aug. 26 flash floods, described the conditions inside the tunnels. "We found tunnels were filled with mud like toothpaste in a tube," he said. "There was no hollow or empty space inside." Maharjan said he can only fly drones in tunnels that are long and straight, and that searches were challenging because of difficult access and the absence of any empty space.
At the Rasuwagadhi hydropower project on Monday, Maharjan managed to send a drone to search deep inside and all the way to the end of the tunnel but found no sign of any life. He said he used microphone speakers to call out to those possibly trapped. "We used microphone speakers to call out to them. In some places, we even played songs and then waited for a response," he said. "That worked in a few cases and helped us locate people."
The scale of the disaster
The flash floods, which the Philadelphia Inquirer reported were triggered by a glacial collapse that unleashed a torrent of water, have killed more than 1,000 people and left thousands missing in Nepal and Tibet. The torrent caused widespread damage to critical infrastructure, including roads, buildings, bridges, and hydropower plants, in the latest sign of growing risks across the rapidly warming Himalayas.
At least 900 workers are still missing from 12 hydropower projects buried under mud and debris, according to the Independent Power Producers' Association of Nepal. About 500 of them are believed to be trapped inside power plant tunnels. Some workers in the tunnels managed to call for help when the disaster struck, according to Mohan Kumar Dangi, president of the association. It was unclear whether rescuers have had any contact with the trapped workers since the initial calls for help.
Drones as a growing tool
Nepal's drone ecosystem began taking shape after the 2015 earthquake, when international agencies brought the technology for damage assessment and recovery operations. The country's private sector has provided drone-based services in Bhutan for multi-hazard risk assessment, according to the World Bank. Operators say drones are "the cheapest mode of transporting supplies compared to choppers."
Airlift Technology, which assembles drones in Kathmandu using imported components, says the next step is enabling the technology to be used more widely. Pandey said, "We just need an appropriate policy to promote such a life-saving machine." There are limits to drone use, including payload capacity, range, and weather conditions, but the technology is rapidly shedding its image as a mere tool for photography and mapping and emerging as an unlikely lifeline during disasters.