Fire foci assessment in the Western Amazon (2000-2015)

摘要

Burning is a practice widely used by rural producers in Brazil, mainly in the Amazon region, as the main instrument to prepare the land for agriculture. In this study, we used the data of all heat foci in the Western Amazon, Brazil, provided by the National Institute for Space Research through its Database of Burns (BDQueimadas). This database often has some redundancies owing to the detection of the same burn more than once or capture of the same fire focus by different environmental satellites, resulting in an overestimation of data. In the present study, we optimize a method to reduce redundancies in an extensive database for the Western Amazon for the time period of 2000-2015, using a model for the identification and exclusion of duplicate heat foci, utilizing the ArcGIS 10.2 software. Kernel density estimates were used and correlated with average precipitation of each year obtained from Tropical Rainfall Measuring Mission (TRMM) satellite (product 3B43). From a total of 1,273,971 heat foci obtained from all environmental satellites, only 433,267 were maintained for the whole period of study (2001-2015), indicating a reduction of approximately 66%. NPP-375 (Suomi National Polar-orbiting Partnership, 375 m of spatial resolution) was the most redundant environmental satellite. The fire foci occurrence showed high correlations with rainfall as well as El Nino events. This work could also delineate areas in the Western Amazon that are most vulnerable to drought and resulting fires.