The Portuguese Large Wildfire Spread Database (PT-FireSprd)

The Portuguese Large Wildfire Spread Database (PT-FireSprd v2.0 ) includes the reconstruction of the spread of 155 large wildfires that occurred in Portugal between 2015 and 2024. It includes a detailed set of fire behaviour descriptors, such as rate-of-spread (ROS), fire spread direction, fire growth rate (FGR) and fireline intensity. The wildfires were reconstructed by converging evidence from complementary data sources, such as satellite imagery/products, airborne and ground data collected by fire personnel, official fire data and information in external reports. We then implemented a digraph-based algorithm to estimate the fire behaviour descriptors. Fireline intensity was estimated using Byram's equation assuming full fuel load consumption as provided by national level fuel maps. PT-WFireSprd database is organized in 3 levels: L1: Wildfire Progression, representing the spatial and temporal evolution of the wildfire spread (i.e. where and when). L2: Wildfire Behavior, including quantitative behavior descriptors of how a wildfire burned, such as the rate-of-spread (ROS), fire growth rate (FGR) and fire line intensity (FLI) L3: Simplified Wildfire Behavior, averaging fire behavior over longer periods that represent relatively homogenous fire runs. The data from the different levels is composed by a large set of maps that can be useful for several applications and target users. The PT-FireSprd is the first open access fire progression and behaviour database in Mediterranean Europe, dramatically expanding the extant information. Updating the PT-FireSprd database will require a continuous joint effort by researchers and fire personnel.