Evaluation for rain erosivity for Campos Novos (SC) during the 1981-1990 period

Abstract

Rainfall erosion is resultant from rainfall erosivity and soil erodibility. The knowledge of the erosivity, in this way, is a valious guide for recommendation of the soil tillage practices to reduce the rainfall erosion. This work was carried out to determine the rainfall erosivity of Campos Novos, SC, Brazil, its annual distribution, and its relation with precipitation. The research was conducted in 1991 at the Centro de Ciências Agroveterinárias in Lages, SC, situated at 27°24' South latitude and 51°12' W longitude. For the rainfall erosivity calculation the method proposed by Wischmeier, modified by Cabeda was used. The rainfall coefficient (Rc) was calculated using the method of Fournier, modified by Lombardi Neto. The relations were made by the linear regression. The mean annual erosivity index (EI₃₀) was 6329,3 MJ.mm.ha^-1.h^-1.year^-1. In february, the index was 16,5% of the annual total EI₃₀. The equations determined were: EI₃₀ = 3,963P - 51,871 (r = 0,532 ns) and EI₃₀ = 22,626Rc + 238,585 (r = 0,504 ns), respectively for precipitation (P) and rainfall coefficient (Rc).