Modelagem espacial da qualidade da água usando geotecnologia na bacia hidrográfica de Santana- Rj

Abstract

The physiografic, hydrological and demographic characteristics of the watersheds influence the characteristcs of their water bodies due to the physical-chemical-biological processes in the system, which requires attention to possible states of degradation and eutrophication. The contribution of nutrients such as total nitrogen and phosphorus as a function of the anthropic occupation and the different uses and occupations of the soil lead to pressure zones in the water quality modeling with the support of a hydrologically constricted digital elevation model of the basin and geotechnologies with the aim of evaluating and estimating the spatial variability of the total load of hydrologically constricted digital elevation model of the basin and geotechnologies with the aim of evaluating and estimating the spatial variability of the total load of phosphorus and nitrogen in the Santana-RJ watershed. The estimation of these nutrients in terms of the corresponding diffuse and concentrated potential loads provided the conditions to model the spatial distribution of nitrogen and phosphorus loads in the drainage network. In addition, hydrological analysis including rainfall and streamflows was performed for the Santana basin as a support for the future studies of hydrological modeling with the purpose of estimating concentration of the nutrients evaluated. It was observed a balance in the contribution of concentrated and diffuse total phosphorus loads. Overestimation of the observed values in the upper part of the basin and underestimation in the region of the Santana reservoir were verified. It was concluded that the high potential nutrient load from the Santana watershed conditions its water bodies to eutrophic states, favoring the degradation of water quality and the appearance of algal blomms and macrophytes.