IMPACTO DAS PRECIPITAÇÕES NA CONCENTRAÇÃO DE FOSFATO EM ÁGUAS PLUVIAIS: UM ESTUDO DE CASO NA BACIA DO RIBEIRÃO CONCÓRDIA

Abstract

This study investigates the quality of rainwater in the Ribeirão Concórdia Basin, in the municipality of Lontras, Santa Catarina, with a specific focus on phosphate concentration. The research covered precipitation data and phosphate concentrations collected at four different points throughout 2015, 2016 and 2017. The methodology included determining the chemical phosphate load using specific equations and the decadal rainwater balance. The results indicate that the concentration of phosphate in rainwater is influenced by the intensity and frequency of precipitation. In periods of lower precipitation, an increase in phosphate concentrations was observed, while more intense precipitation tended to dilute the chemical load, with the exception of isolated events where the previous accumulation of phosphate resulted in high concentrations. The annual analysis of phosphate loads revealed that, at some points, concentrations exceeded the limits established by Brazilian environmental legislation. This excess can lead to eutrophication, with negative impacts on water quality and aquatic biodiversity. The research highlights the need for integrated rainwater management strategies that include sustainable agricultural practices and the creation of retention zones.