Fuego, vegetación y paisaje en el Noroeste peninsularcaracterización de zonas quemadas en espacios naturales mediante SIG y teledetección

Laburpena

It addresses the study of fire from a spatially explicit multi-scale view, characterizing the relationship between vegetation and fire risk analysis by fire, zoning and the study of burned vegetation recovery after disturbance. This is the aim of this study into three natural areas of western Castilla y León. As a first step, we generated a map of fires (more than 5 hectares) using satellite images Landsat 5 and 7. Then addressed the fire risk assessment of spatially explicit way, using an approach of logistic regression and classification trees. Finally, we assessed vegetation recovery after lire using spectral indices (derived from the Images Landsat) considered in the previous analysis. The use of Landsat images at various scales allowed us to characterize the spatial pattern generated by the disturbance-regeneration process due to fire, the mapping of burnt areas received a total reliability of 88% and allowed to characterize the fire regime for the study areas. The fire risk models generated had a reliability of 70%, indicating its validity as auxiliary information to identity hot spots that allow the design of preventive measures. Spectral indices were useful for detailing the spatial pattern of risk that defines structural environmental variables “static”(on the timescale of the study): topography, accessibility and vegetation type. The slope was the most decisive coarser spatial scales, while at finer scales are more variables needed to estimate the probability of occurrence of fires. In all cases the correlations between structural parameters sampled in the field and spectral indices were significant, except for species richness, suggesting its validity tot monitoring the state of vegetation. At both the landscape and pixel, identified three phases in the dynamics of the values of the indices: (i) increased intense and rapid in the first two years after the fire, (ii) gradual and slow increase between the third and eighth year and thereafter, (iii) dynamic equilibrium. In the study area, the recurrence of fires did not affect the capacity for regeneration.