Mapping fire events in the transition of Amazon and Cerrado biome using remote sensing
Abstract:Abstract to AGU
Fire is considered one of the determinant factors that have shaped Cerrado biome, the Brazilian Savanna, considered the most biodiverse savanna in the world. At the same time, fire has not acted a major role during the evolution of the Amazon Forest due to the strong capacity it has to resist burning. Recently, with the expansion of the agricultural activities in the central Brazil, about 49% of the Cerrado has been converted to other uses and as deforestation vector runs towards the Amazon Forest it modifies the natural moist microclimate in the edges of the forest, increasing the likelihood of wildfires. Every year these ecosystems suffer with several fire events responsible for large burned areas, causing losses of biomass, biodiversity, soil nutrients, and releasing tons of CO2 that help climate change.
The occurrence of fires has a direct relationship with the climate of the central portion of the south american continent, charaterized by a two seasons regime, wet and dry, each one lasting around 6 months. In this region is located the ecotone of these two majors Brazilians ecosystems. In the Cerrado biome fire is often used to manage pasture, stimulating the regrowth of natural grasses used as pasture and also to open new areas for agriculture. There are researches showing that people have been traditionally using fire as a lower cost way to manage their lands for different purposes. In the Amazon forest the cycle of deforestation started around the 60’s with incentives from the federal government to populate the region in the middle of the last century, and most recently by the progress of the commodities prices, such as soybean and sugar-cane, that has occupied vast areas of the Cerrado and is marching towards the forest. In the Amazon, fire is frequently used to further open the areas that were previously logged selectively and then converted to agricultural uses.
Given the ecological importance of the Amazon Forest and Cerrado biome and the threat fire is posting to them, this research aims to perform a multiscale study of fire events in the transition zone between the two biomes, using MODIS to identify fire scars in a coarser resolution and then refining the scale using Landsat images, aiming to confirm the fire scar identification and compare the differences between the measurements performed using the two methods.