Maximum rainfall and erosivity during the rainy season (2011-2020) in the municipality of Pau dos Ferros, semi-arid region of Rio Grande do Norte, Brazil

Abstract

The intensity and volume of rainfall are determining factors in erosive processes, especially in the semi-arid regions where this phenomenon occurs concentrated during a specific period of the year. In Pau dos Ferros, Rio Grande do Norte, challenges such as floods and soil loss are evident, highlighting the lack of recent studies on erosivity. Thus, considering that this gap compromises the necessary foundation for conservation practices and a thorough understanding of these processes, this work aims to analyze the variation in the monthly erosivity pattern during the rainy season in the municipality, between the years 2011 and 2020. To achieve this, it uses daily rainfall data, application of equations for rainfall coefficient, intensity, duration, and frequency, as well as historical and estimated erosivity indices, and classification of the type of monthly rainfall erosivity. The results showed that the rainy season in Pau dos Ferros was concentrated from February to May, with the first two months being the most significant in annual accumulated precipitation (1,358.5 mm and 1,410.6 mm) and rainfall coefficients, as well as que the rains of, no more that fifteen minutes, represent a bigger immediate erosivity if compared to the ones of thirty-minute-long, which indicates a greater cumulative power. Furthermore, the estimated monthly erosivity for February and March exceeded the historical average, while April and May remained close to expectations. Finally, it is expected that this study can support territorial planning actions, in addition to encouraging additional research on the relationship between erosivity, soil types and land use.