Testing a Novel Scalable-Resolution Fire Danger Index Based on Sentinel Imagery: The Montiferru Megafire Case-Study

The incidence of wildfires and megafires with their disastrous consequences is increasing all over the planet, both in terms of burned area surface and in terms of power released by the fires. For this reason, the strategic importance of wildfire prevention is greater than ever, and providing the decision makers with powerful and state-of-the-art tools is an utmost priority. To this end, satellite observations offer a privileged platform to cover large spatial scales with a high time frequency. However, the most popular fire danger products tend to cover very large spatial scales at a coarse resolution, and inherently lack the capability to provide a level of detail which is very useful at the local scale. At the same time, using different products at different spatial scales would be impractical, and would increase the workload and training requirements of the personnel. To this end, this paper proposes a scalable-resolution fire danger index, named Daily Fire Danger Index, based on Sentinel-2 L2A and Sentinel-3 Synergy products. This novel index exploits both weather and satellite data to estimate all the main fire weather variables, and is calibrated using the historical records of wildfire occurrence in the area of interest.