Using drones to speed up response efforts to Cyclone Ana

Tropical cyclone Ana has wreaked havoc across Malawi's southern region. The huge storm caused widespread flooding that severely damaged homes, roads, schools, and health facilities. The cyclone, which struck in late January, also washed away tens of thousands of hectares of crops.

According to preliminary estimates from the Department of Disaster Management and Preparedness (DoDMA), the floods have affected more than 865,651 people. Around 100,000 have been displaced and are being housed in 122 displacement sites. Another 100,000 students are out of school, 158 people have been injured, 33 have died, and three are missing.

In collaboration with the African Drone and Data Academy (ADDA), UNICEF is assisting Malawi's  Department of Disaster Management Affairs to assess damage using drone collected images. The drones have helped to speed up the assessment process and informed planning for response activities.

Dumisani Kaliati, a drone technician at ADDA, led the drone assessment team, collecting aerial images of the affected area, mapping a flood-affected spot around usually busy Kamuzu Road in the town of Chikwawa.

He said the drone imagery was able to determine an area surrounding Kamuzu bridge was particularly problematic as the road had been cut and damaged in three places, blocking traffic between Chikwawa and Blantyre.

"The fact the road was cut meant emergency supplies couldn’t reach struggling families in Chikwawa and Nsanje. In total we mapped 26 hectares of land in three hours,” said Kaliati, who was trained to used drones during a workshop held by UNICEF and Virginia Tech in 2017.

He said drones provided a quick, cost-effective way of collecting high-quality geospatial data, which was used to generate high-quality maps. These maps contain useful features such as geographical coordinates and land elevation details, useful in decision making on issues like where to locate and build emergency shelters.

“The images provided a bird's-eye view of the affected area, which has been crucial to the emergency response. It gives the planners a realistic picture of the problem at hand and helps rescue workers to be more effective."

He said the collected in Chikwawa were used to assess damage. The drone images were also used to develop orthomosaic maps which in future may be used an inform decision-like on how to redirect traffic in the places where roads have been damaged.

When combined with other sensors such as infrared and lidar, data collected by drones can provide useful insights such as heat signatures and underground object detection, which are critical in rescue missions but are invisible to the human eye.

Drone data also provides raw images that can be used to inform communities and assist workers with infrastructure planning when they start to rebuild.

Michael Scheibenreif, UNICEF Malawi innovation specialist, said incorporating drones into the emergency response effort had shortened the time it would have taken to conduct a needs assessment and follow-up with response activities.

"The reduction in planning and response time can make a difference between life and death," Scheibenreif said.

As part of the cyclone response effort, UNICEF Malawi is also collaborating with the Department of Climate Change and Meteorological Services (DCCMS) to develop a flood model that will be able to predict the extent to which floods will continue to damage infrastructure.

The model is being developed along the North and South Rukuru rivers in the Rumphi district, in the country's north. Once in operation it will help to reduce loss of life, property, and livestock.