Estudio crítico de los índices de severidad y la superficie afectada por el incendio de Sierra de Luna (Zaragoza)

Abstract

Resumen: Para la determinación del área quemada y la severidad asociada del incendio de Sierra de Luna (Zaragoza), ocurrido el 4 de julio de 2015, se han calculado tres índices espectrales derivados de Landsat-8: NDVI, NBR y BAI. Comparando los resultados obtenidos por cada uno de ellos, en un incendio con extensas zonas de cultivo entre zonas arboladas, se ha determinado que la combinación de ΔNBR y BAI mejora sustancialmente la determinación del área realmente quemada, tanto en su perímetro exterior como en las zonas aisladas no quemadas de su interior. Para el cálculo de la severidad, se propone una metodología basada en el análisis de las diferencias de NBR, antes y después del incendio, y su combinación con el BAI, en función del valor previo al incendio de los índices NBR y de NDVI.Palabras clave: severidad, Landsat, NDVI, NBR, BAI. Critical analysis of severity indices and affected surface by the wildland fire on Sierra de Luna (Zaragoza)Abstract: To determine the area burned by fire and its associated severity related to this forest fire taken place in Sierra de Luna (Zaragoza), on July 4 th , 2015, three spectral indices derived from Landsat-8 imagery have been calculated: NDVI, NBR and BAI. Comparing the results obtained from each of them, in a wildland fire with extensive crop areas surrounded by forested areas, it has been demonstrated that combination of ΔNBR and BAI substantially improves the calculation of the burned area, concerning both in its external perimeter and in the unburned zones inside of the perimeter. For severity calculation is proposed a new methodology based on before and after NBR differences and its BAI combination, as a function pre-fire values of NBR and NDVI indices.

Monitoring Wildfires in the Northeastern Peruvian Amazon Using Landsat-8 and Sentinel-2 Imagery in the GEE Platform

“…The greater availability of medium spatial resolution sensors enabled the development of several algorithms for extracting BA at local and regional levels [31][32][33]. In parallel to this, the spectral analysis of satellite imagery nowadays tends to use manifold spectral indices, which employ the visible range of the Electromagnetic Spectrum (VIS), as well as the Near-Infrared (NIR), the Short-Wave Infrared 1 (SWIR1), and the Short-Wave Infrared 2 (SWIR2) ranges to assess burnt areas and/or burn severity of wildfires [12,34,35]. Among those indices, we ought to mention the Normalized Burn Ratio (NBR) [36] and its difference in relation to the value obtained prior to the wildfire event (dNBR), which allows the evaluation of the BA extent and severity [37].…”