Estimativas de cargas poluidoras em bacia hidrográfica, com ênfase nas cargas geradas para o parâmetro fósforo

Abstract

Water is an essential factor in the formation and maintenance of life. However, the water sources have suffered a strong impact on the quantitative and qualitative aspects. This paper aims at contributing to the understanding of the modeling of water quality related to sources of diffuse pollution. ArcView Generalized Watershed Loading Function (AVGWLF) model was used to demonstrate the phosphorus loads generated in an experimental watershed. Maps were created such as: use and land cover, soil types, rivers, concentration of phosphorus in the soil, among others, used as input files of the model. Four scenarios of use and land cover were also created, they are: native and eucalyptus forest, pasture, coffee and bare soil and then compared the loads of phosphorus generated for each scenario, between 1998 and 2002. The parameter MU_AWC has a strong influence on the generation of the phosphorus load in groundwater in the simulations, because the increase of the parameter value reduces the simulated load. The results simulated by the model for the monthly charges accompanying seasonal variations of the rainfall. The simulated values of phosphorus vary quantitatively in the following order, considering the scenarios of land use: native and eucalyptus forest, pasture, coffee and bare soil.