Assessment, regionalization, and modeling rainfall erosivity over Brazil: Findings from a large national database

David Bruno de Sousa Teixeira; Roberto Avelino Cecílio; Michel Castro Moreira; Gabrielle Ferreira Pires; Elpídio Inácio Fernandes Filho

doi:10.1016/j.scitotenv.2023.164557

Assessment, regionalization, and modeling rainfall erosivity over Brazil: Findings from a large national database

Sci Total Environ. 2023 Sep 15:891:164557. doi: 10.1016/j.scitotenv.2023.164557. Epub 2023 Jun 6.

Authors

David Bruno de Sousa Teixeira¹, Roberto Avelino Cecílio², Michel Castro Moreira³, Gabrielle Ferreira Pires⁴, Elpídio Inácio Fernandes Filho⁵

Affiliations

¹ Federal University of Viçosa, Department of Agricultural Engineering, Viçosa, MG 36570-900, Brazil. Electronic address: david.teixeira@ufv.br.
² Federal University of Espírito Santo, Department of Forest and Wood Sciences, Jerônimo Monteiro, ES 29550-000, Brazil. Electronic address: roberto.cecilio@ufes.br.
³ Federal University of Viçosa, Department of Agricultural Engineering, Viçosa, MG 36570-900, Brazil. Electronic address: michelcm@ufv.br.
⁴ Federal University of Viçosa, Department of Agricultural Engineering, Viçosa, MG 36570-900, Brazil. Electronic address: gabrielle.pires@ufv.br.
⁵ Federal University of Viçosa, Department of Soil Science, Viçosa, MG 36570-900, Brazil. Electronic address: elpidio@ufv.br.

PMID: 37286003
DOI: 10.1016/j.scitotenv.2023.164557

Abstract

In this study, we used a large national database to assess the rainfall erosivity (RE) patterns in time and space over the Brazilian territory. Thereby, RE and erosivity density (ED) values were obtained for 5166 rainfall gauges. Also, the concentration of the RE throughout the year and the RE's gravity center locations were analyzed. Finally, homogeneous regions regarding RE values were delimited and estimative regression models were established. The results show that Brazil's mean annual RE value is 5620 MJ mm ha^-1 h^-1 year^-1, with considerable spatial variation over the country. The highest RE magnitudes were found for the north region, while the northeast region shows the lowest values. Regarding the RE's distribution throughout the year, in the southern region of Brazil, it is more equitable, while in some spots of the northeastern region, it is irregularly concentrated in specific months. Further analyses revealed that for most of the months, the RE's gravity centers for Brazil are in the Goiás State and that they present a north-south migration pattern throughout the year. Complementarily, the ED magnitudes allowed the identification of high-intensity rainfall spots. Additionally, the Brazilian territory was divided into eleven homogeneous regions regarding the RE patterns and for each defined region, a regression model was established and validated. These models' statistical metrics were considered satisfactory and, thus, can be used to estimate RE values for the whole country using monthly rainfall depths. Finally, all database produced are available for download. Therefore, the values and maps shown in this study are relevant for improving the accuracy of soil loss estimates in Brazil and for the establishment of soil and water conservation planning on a national scale.

Keywords: Erosivity index; R-factor; Soil and water conservation; Soil erosion; Universal soil loss equation.