The role of forest fires in land use/land cover changes in Portugal

Abstract

In the last decades, Portugal registered substantial land use / land cover changes (LULCC) driven by the abandonment of rural areas, fast urbanization, and expansion of metropolitan areas and costal touristic centers motivated by the significant socio-economic development. Consequently, there significant transitions incurred among different land use classes as well as a homogenization of the fuel bands, increasing the extension and complexity of fire prone areas. Portugal was particularly affected by forest fires (FF) with more than 18,000 FF/year and annual burnt area (BA) of 107,000 ha/year since 1980, while the average size of such events has increased from 4 ha to 13 ha in the last 10 years. This study analysed the FF occurred in continental Portugal between 1990 and 2013, with the main focus on: (i) assess the global and regional differences/similarities in LULCC and fire regime; (ii) evaluating the role of FF on LULCC and; (iii) to provide a better understanding (identification and characterization) of space-time cluster distribution of FF. We used the following datasets: (i) land use/land cover inventories from CORINE; (ii) BA polygons from the Portuguese Institute for the Conservation of Nature and Forests. A geospatial methodological approach, based on GIS analyses, was developed to identify LULCC and to characterize the impact of FFs on these changes; then, cluster analyses were performed to examine patterns in FFs distribution and, finally, to discover how landscape factors control FF clusters. This research provides a quantitative assessment of the relationship between LULCC and FFs in Portugal. The authors believe that the obtained results provide a valuable contribution to: (i) characterize the LULCC in Portugal; (ii) assess the role of FFs on LULCC; (iii) support a better landscape management to reduce related losses of life, property and assets; as well as, (iv) promote educational events to increase public awareness to the causes and consequences of FF.