Mapping after a flood with drones

On September 2023, Tsarevo, a coastal municipality in Bulgaria, was hit by catastrophic flash floods, resulting in four fatalities. The municipality declared a state of disaster.

Numerous buildings were submerged, several bridges collapsed, and water levels in some areas reached up to 2 meters. The disaster required fast and safe solutions, as access to the affected areas was perilous due to the severe devastation.

Rapid disaster response with the eBee X drone

In response to the disaster, the Bulgarian Ministry of Environment and Water commissioned Sofia University St. Kliment Ohridski’s Center for Geospatial Research and Technology to conduct rapid mapping of the flood-affected region. The primary objective was to enhance the efficiency of recovery efforts.

The mapping scope encompassed two riverbeds and the path of destruction caused by heavy rainfall. The university’s team deployed two eBee X drones, each equipped with RGB cameras, specifically S.O.D.A., for an RTK multi-drone mission.

Vladislav Trenkin, from the mapping team

“We chose the eBee X because of its ability to provide extremely detailed and precise data and cover vast territories in a very short time”

This allowed for the creation of 2D orthomosaics and 3D elevation models across the affected areas during two simultaneous drone flights, which took around 50 minutes. The subsequent image processing using Pix4D for the entire area was completed in just 4 hours.

The entire operation, including travel from Sofia to Tsarevo of the team, data processing, and publication, was accomplished within a single day, thanks to the use of the eBee drones.

Supporting reconstruction activities thanks to drone data

The 2D and 3D models of Tsarevo, created using data from the eBee X mapping drones, are proving invaluable to the expert commission overseeing post-flood activities. The first action taken after the authorities received the processed data was to locate two submerged cars.

In general, these models are aiding in assessing the overall condition of the flood-affected region, including damage assessments and the extent of affected areas.

This high-detail, large-scale mapping, conducted in a remarkably short time frame following the flooding, was a pioneering achievement. Government and municipal authorities were astonished by the results. The dataset is publicly available for use on the Ministry of Environment’s website.

The Bulgarian government reports that the situation in Tsarevo is gradually returning to normal.

Explore the dataset of this use case here.