Drone swarms in fire suppression activities.

Recent huge technological development of Unmanned Aerial Vehicles (UAVs) can provide breakthrough means of fighting wildland fires. We propose an innovative forest firefighting system based on the use of a swarm of hundreds of UAVs able to generate a continuous flow of extinguishing liquid on the fire front, simulating rain effect. Automatic battery replacement and refilling of the extinguishing liquid ensure the continuity of the action, and fire-resistant materials protect drones exposed to possible high temperatures. We demonstrate the validity of the approach in Mediterranean scrub first computing the critical water flow rate according to the main factors involved in the evolution of a fire, then estimating the number of linear meters of active fire front that can be extinguished depending on the number of drones available and the amount of extinguishing fluid carried. A fire propagation cellular automata model is also employed to study the evolution of the fire. Simulation results suggest that the proposed system can successfully integrate, or in case of low-intensity and limited extent fires completely replace, current forest firefighting techniques.