Distribuição espaço-temporal dos focos de queimadas na APA de Alter do Chão

Abstract

Anthropic activities from the twentieth century have altered landscapes using fire, which theoretically would be present on the savanna surfaces and absent in the rainforests, this represent alternative states of vegetation disturbed by fire (bistability). The APA of Alter do Chão in Santarém-PA is the area of study of the spatial-temporal distribution of hotspots that were correlated with environmental variables (precipitation, relative humidity, air temperature, ONI and AMO). A strong correlation was only found with ONI. Hotspots were located considering changes over three decades on soil cover, classified using remote sensing imagens using a supervised classification (minimum distance algorithm) by the Semi-automatic Classification Plugin of QGIS. In 19 years (1998-2016), 276 hotspots were registered in the APA, with December being the month with the highest number of hotspots. 2015 registered the highest historical number of hotspots (89). In 30 years (1986- 2016) 2,367.3 ha of forest and 1,422.4 ha of savanna were destroyed in the APA of Alter do Chão, making 22.9% of soil cover. The correlation between hotspots in savanna and deforested areas is strong.