Mapeamento e análise da erosividade da chuva na sub-bacia do Alto Paraíba (Paraíba).

Abstract

Water erosion is one of the most damaging phenomena to soil and human activities, especially agricultural activities. This study aimed to analyze the rainfall erosivity in the Alto Paraíba sub-basin through geotechnology. Was used rainfall data of 103 years of observation between 1911 and 2014. In the classification of erosivity, erosive rains equal to or greater than 10mm, or equal to or greater than 6mm in a maximum period of 15 minutes were considered. To calculate the R factor, the monthly average and the annual average were used. Was used Surfer® program 11 for the distribution of erosivity and development of maps using the Kriging method. It was identified that the average annual distribution of the rain erosivity factor was 3,477.57 mm.ha-1.year-1; and the standard deviation of the average monthly EI30 erosivity parameter showed a value of 639.96 mm.ha-1.year-1, and the coefficient of variance showed a value of 0.184. The region to the northwest of the basin was the one with the greatest erosivity. The months of March and April had the greatest potential for losses due to erosivity.