A novel urban vegetation mapping approach for fire risk assessment: A Mediterranean case study

A series of urban wildfires that engulfed the Mediterranean in recent decades raised the problem of introducing urban vegetation into fire management. While the Wildland-Urban Interface (WUI) concept includes urban areas in the fire risk analysis exists today, the common approach used in WUI for cities as fire-resistant territories proved to be a failure in practice since wildfire not only penetrates the urban areas but also crosses them by jumping from one green patch to another. Understanding urban areas as flammable demands evaluating the ability to predict the wildfire spread in the city. Among the existing risk assessment approaches only fire behaviour modelling describes the physical processes that occur in an urban wildfire case: the rapid fire spread in the city by ember attacks can be simulated by the spotting analysis. Implementation of the mentioned method requires information about the fuel-related areas within the urban landscape. The suggested method for identifying urban fire-supporting areas based on the vegetation proportion threshold allows a highly accurate prediction of fire spread distance for a certain time step. The proposed approach serves the fire behaviour simulation in large (10-20 ha) urban areas, which previously was challenging due to the high computational load. The outcomes of the presented study can support fire management in an urban landscape both by producing fire risk maps and assessing the spatial distribution of fire-supporting patches for better fuel treatment planning.