Erosividade e risco de desmatamento em áreas de cerrado

Abstract

The Cerrado is an important biome from both an environmental and agricultural perspective. It is a domain rich in biodiversity, with many endemic species of fauna and flora, valuable for water resources and for agricultural production. With the proposal of contributing with information regarding the Cerrado, the study area includes 101 municipalities located mostly within the Cerrado biome, 25 of which are in the states of Mato Grosso, Goiás, and Minas Gerais, and another 26 in Mato Grosso do Sul. There are two chapters in scientific paper format: (i) "Rainfall erosivity in Brazilian Cerrado municipalities"; (ii) "Deforestation risk for municipalities located in Cerrado areas". In the first, the objective was to determine rainfall erosivity, for which simple linear regression was used to fill gaps in 20-year historical series for 81 rainfall stations and then 16 regionally calibrated formulas were applied. The erosivity index (El30m) was highest between October and March, and lowest between April and September. The annual rainfall erosivity or R factor ranged from 3,713.1 to 12,345.6 MJ mm ha-1 h-1 year-1, with the lowest values for the municipalities in the eastern region of MT and the highest for the northeastern region of MS. In the second article, the objective was to verify the deforestation risk for the areas of natural vegetation cover in 2019. To achieve the objective the methodology called ACEU was used, which seeks to determine the risk of deforestation through the combination of factors considered key to deforestation, they are: accessibility, cultivability, extractable resources and protected areas. Based on the factors the methodology defines "very low", "low", "medium", "high" and "very high" risk classes for deforestation, in which losses of 10, 30, 50, 70 and 90% of natural vegetation cover are expected over a 20-year period. In 2019, the municipalities of Mato Grosso do Sul had 3,376,271.62 ha of natural vegetation cover (40.36% with medium risk of deforestation). Goiás municipalities had the lowest natural vegetation cover, 2,410,893.09 ha (28.19%) with very low risk of deforestation, while, Minas Gerais municipalities the vegetation cover was 2,639,221.74 ha, with about 27.01% with medium risk of deforestation. In these three states the differences between estimated and measured deforestation was 14,769.96, 3,985.99 and 39,673.41 ha, respectively. The municipalities of Mato Grosso had vegetation cover of 8,443,799.21 ha, 30.01% with very low risk of deforestation (protected areas) and the difference between estimated and measured deforestation was 65,892.49 ha