Variabilidade temporal e espacial da erosividade das chuvas no Estado de Goiás segundo três modelos

Abstract

The Universal Soil Loss Equation (USLE) is widely used to estimate soil erosion, with rainfall erosivity (R) being a key factor. This study evaluated three different methods for estimating the EI30 index in the state of Goiás, proposed by Morais et al. (1991), Lombardi Neto and Moldenhauer (1992), and Silva et al. (1997), using precipitation data from the Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) from 1985 to 2017. The annual variability of erosivity was analyzed through linear regressions and statistical tests. Results showed that the average EI30 values for the models of Lombardi Neto and Moldenhauer (1992), Silva et al. (1997), and Morais et al. (1991) were 6,658.82, 6,947.32, and 13,017.70 MJ mm ha⁻¹ h⁻¹ year⁻¹, respectively, with an annual variation of 9.3%. The model by Silva et al. (1997) performed best (R² = 0.9997) and was more compatible with the observed mean values. It was concluded that erosivity varied significantly over time, though with low magnitude, and that the average of the three models adequately represents the spatial and temporal variability of rainfall erosivity in Goiás.