Article Forest Fire Spreading Using Free and Open-Source GIS Technologies Michele Mangiameli 1, * , Giuseppe Mussumeci 1 and Annalisa Cappello 2   Citation: Mangiameli, M.; Mussumeci, G.; Cappello, A. Forest Fire Spreading Using Free and Open-Source GIS Technologies. Geomatics 2021, 1, 50–64. https:// doi.org/10.3390/geomatics1010005 Received: 13 December 2020 Accepted: 22 January 2021 Published: 25 January 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department of Civil Engineering and Architecture, University of Catania, 95124 Catania, Italy; giuseppe.mussumeci@unict.it 2 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, 95125 Catania, Italy; annalisa.cappello@ingv.it * Correspondence: michele.mangiameli@unict.it Abstract: Forest fires are one of the most dangerous events, causing serious land and environmental degradation. Indeed, besides the loss of a huge quantity of plant species, the effects of fires can go far beyond: desertification, increased risk of landslides, soil erosion, death of animals, etc. For these reasons, mathematical models able to predict fire spreading are needed in order to organize and optimize the extinguishing interventions during fire emergencies. This work presents a new system to simulate and predict the movement of the fire front based on free and open source Geographic Information System (GIS) technologies and the Rothermel surface fire spread model, with the adjustments made by Albini. We describe the mathematical models used, provide an overview of the GIS design and implementation, and present the results of some simulations at Etna volcano (Sicily, Italy), characterized by high geomorphological heterogeneity, and where the native flora and fauna may be preserved and perpetuated. The results consist of raster maps representing the progress times of the fire front starting from an ignition point and as a function of the topography and wind directions. The reliability of results is strictly affected by the correct positioning of the fire ignition point, by the accuracy of the topography that describes the morphology of the territory, and by the setting of the meteorological conditions at the moment of the ignition and propagation of the fire. Keywords: GIS; forest fires; Rothermel model; DSS 1. Introduction In recent years, forest fires has become one of the major problems in land management. The phenomenon is favored by the global warming (including an increase in the mean annual of temperature, relative humidity and wind velocity) that causes a growth of the annual number of fires and subsequent burned areas [1]. This determines, in the affected territory, the loss of a huge quantity of plant species, an increasing of desertification, risk of landslides, soil erosion and death of animals. Moreover fires can represent a danger to population centers located in the vicinity of wooded areas and obviously an economic damage for the community [2,3]. Although some ecosystems have acquired adaptive traits that enable them to persist and reproduce in fire-prone environments (e.g., [4,5]), fires generally cause impoverishment of the biocoenosis, including the death of a part of the plants present and of a large number of animals, and the serious suffering or damage of other plants. This will lead to a simplification of deleterious ecosystems involved: If the vegetation and animal population are strongly impoverished, the ecosystem exposed to various stress factors (prolonged drought, new types of damage to the woods, the arrival of species pests arboreal, explosive development of a few plant forms with a tendency to become pests, etc.) may not find adequate compensatory mechanisms in itself and suffer a serious progressive decline. In recent years the meteorological and environmental conditions have favored the ignition of forest fires. Since the beginning of 2000s, it was estimated that about 50,000 fires occur each year in the Mediterranean basin, affecting more than 600,000 ha [2]. According Geomatics 2021, 1, 50–64. https://doi.org/10.3390/geomatics1010005 https://www.mdpi.com/journal/geomatics