Assessment of Forest Fire Risk in European Mediterranean Region: Comparison of Satellite-Derived and Meteorological Indices

Forest fires are a major hazard to Mediterranean forests where, on average, half a million hectares of forested areas are burned every year. It is for this reason that the assessment of fire risk lies at the heart of fire prevention policies in the region. Often, the estimation of forest fire risk involves the integration of meteorological and other fuel-related variables leading to an index that assesses the different levels of risk. Two indices that are frequently used to estimate the level of fire risk are the Fire Weather Index (FWI) and the Normalized Difference Vegetation Index (NDVI). Although the correlation between the number of fires and the level of risk determined by the indices has been demonstrated; however the analysis that lead to this conclusion considered only the areas where the fires took place. The present paper analyzes the behaviour of these fire risk indices both in areas where fires took place and in those where fires did not occur. It analyzes and compares the potential of the two indices to discriminate different levels of fire risk over large areas using quantitative and graphical methods. The analysis is performed considering a dataset of 10 years of fire events, satellite data and meteorological data for Spain. The results show a better performance of the FWI over NDVI in identifying areas at risk of fires.JRC.H.7-Land management and natural hazard

Assessment of forest fire risk in European Mediterranean Region : comparison of satellite-derived and meteorological indices

Tese de doutoramento em Engenharia Mecânica (Riscos Naturais e Tecnológicos) apresentada à Fac. de Ciências e Tecnologia de CoimbraAguarda-se o resumo do autor

Assessment of forest fire risk in European Mediterranean Region : comparison of satellite-derived and meteorological indices

Tese de doutoramento em Engenharia Mecânica (Riscos Naturais e Tecnológicos) apresentada à Fac. de Ciências e Tecnologia de CoimbraAguarda-se o resumo do autor

A Comparative Analysis of the Use of NOAA-AVHRR NDVI and FWI Data for Forest Fire Risk Assessment

Fires are a major hazard to forests in the Mediterranean region, where, on average, half a million hectares of forested areas are burned every year. The assessment of fire risk is therefore at the heart of fire prevention policies in the region. The estimation of forest fire risk often involves the integration of meteorological and other fuel-related variables, leading to an index that assesses the different levels of risk. Two indices frequently used to estimate the level of fire risk are the Fire Weather Index (FWI) and the Normalized Difference Vegetation Index (NDVI). Although a correlation between the number of fires and the level of risk determined by these indices has been demonstrated in previous studies, the analyses focused on the changes in fire risk levels in areas where fires took place. The present study analyses the behaviour of the fire risk indices not only in areas where fires occurred but also in areas where fires did not take place. Specifically, the objective of this work was to compare the potential of the two indices to discriminate different levels of fire risk over large areas. Qualitative and quantitative methods were used to compare the statistical distributions of fire event frequencies with those of fire risk levels. The qualitative method highlights graphically the statistical difference between the values of the indices computed over burnt areas and the overall distribution of the values of the indices. The quantitative method, based on the use of the so-called performance index, was used to evaluate and compare numerically the potential of the indices. The analyses were performed considering very extensive datasets of fire events, satellite data and meteorological data for Spain during a 10-year period. Although the NDVI is assumed to describe the vegetation status as related to fire ignition, the results show conclusively an enhanced performance of the FWI over the NDVI in identifying areas at risk of fires.JRC.DDG.H.7-Land management and natural hazard

On the Suitability of the Use of Normalized Difference Vegetation Index for Forest Fire Risk Assessment

The NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) has often been used for forestry applications, including forest fire risk estimation. The decrement of NDVI values over a particular area has been considered an indicator of vegetation stress and linked to high fire risk. In the Mediterranean region, a large number of fires occurred in areas where the NDVI values were low. Consequently, the link between low NDVI values and fire occurrences was established. However, studies supporting this hypothesis were only based on analysis of areas that suffered fires. Information over similar areas where fires did not occur was not taken into consideration. This study investigates the ability of NDVI to discriminate levels of fire risk in Spain. A very large dataset of satellite sensor images and fire events was used for this purpose. The relative frequency distribution of NDVI values in both areas, those that suffered fires and those where fires did not occur, was compared in a 10 year period. The results highlight that NDVI values on areas were fires took place were similar to NDVI values in areas in which fire did not occur, showing the limitations of using the NDVI as index of fire risk.JRC.H.7-Land management and natural hazard

Software di Calcolo del Volume di Interesse per la Ricostruzione Tridimensionale di Modelli Anatomici dal "Segmented Visible Human Dataset"

Abstract not availableJRC.(ISIS)-Institute For Systems, Informatics And Safet