Modelagem de fogo florestal em clima tropical: avanços para um modelo baseado em processos

Abstract

Forest fire represents a crucial system for the study of interactions between biosphere-atmosphere. Regarding the fire effects on biodiversity conservation, hydrological cycle, terrestrial carbon storage, its impact is even more relevant on tropical forests. The positive feedback among land use/cover, climate and fire threaten the environmental balance and justifies research about the theme. The collaboration between experimental work and spatially explicit modelling allows addressing the phenomena from a process-based point of view, with minor restrictions of spatial and temporal coverage. In this way, the FISC model was developed to study tropical forest fire, and has shown good results for fire region occurrence estimates at Amazonia, as well as simulating fire spread for the Xingu river headwaters. New requirements related to continuity, quality of results, and model performance led the improvements done for FISC during this work. The climatic dataset wasreplaced, model processes were reviewed and new aspects of fire dynamics were included in the model. Thus each numerical method, relative to the ignition and spread components, were revisitedand recalibrated considering new data available for the study area. As results, further on the good fitness obtained for observed patterns of fire intensity and seasonality, FISC was able to represent the consequences of anomalous droughts referenced for Xingu area on fire regimes. The spatial pattern achieved on simulated fire scars represents one of the obtained advances for the result maps. The FISC advances allow to increase the quality of forest fire scenarios due to land use policies andclimate trends, still it broaden model's applications on ecological studies with fire interaction using landscape metrics. Lastly, the model use under operational framework was also evaluated as possible contribution to permanent fire monitoring and prevention efforts.