Estudo ambiental integrado de processos hidrossedimentológicos e nutrientes na bacia hidrográfica do rio Piranga utilizando o SWAT

• Autor(a) principal: Rocha, Everton de Oliveira
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3797
• topic: Planejamento; Gestão; SWAT; SUFI-2; Calibração; Validação; HRU; Planning; Management; SWAT; SUFI-2; Calibration; Validation; HRU; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA::RECURSOS HIDRICOS::PLANEJAMENTO INTEGRADO DOS RECURSOS HIDRICOS

The inadequate occupation, lack of planning, management and conservation of watersheds have triggered environmental degradation processes, such as, reduced water infiltration into the soil, increasing runoff that contributes to the transport of sediments and nutrients to watercourses, and compromises environmental quality of aquatic systems and the environment. The main sources of these processes of deterioration of water bodies is a diffuse source pollution as a result of the intensification and expansion of agriculture and livestock without preparation techniques, soil management and conservation. Because of these numerous factors acting together, the river basin Piranga can be considered with a high level of environmental complexity and therefore deserves special attention. In order to identify and quantify the magnitude of these processes we used the Soil and Water Assement Tool (SWAT) which is a hydrologic model developed to simulate physical processes (natural and anthropogenic), streamflow forecasting, runoff, erosion and transport of sediment and nutrients from watersheds under different managements. To ensure consistency in the data generated after the simulation and the consequent applicability in the study area and its extrapolation to other areas, we performed a calibration and validation in order to extract the maximum potential of the model and features. The calibration and validation made use of the optimization algorithm Sequential Uncertainty Fitting version 2 (SUFI-2) which provided an uncertainty analysis by graphical analysis bands than 95PPU together with the R-factor and Rfactor. Also available is a statistical summary which shows the efficiency coefficient of Nash and Sutcliffe and Determination R2. It was used as a reference fluviometric seven seasons and three monitoring stations of sediment and nutrients. The loads (in kg.ha-1) of sediment yield and nutrient losses, nitrate (NO3) and total phosphorus (TP), are presented considering the hydrological response units (HRU) for the use and occupation. The results of the calibration and validation of the model for flow, sediment and nutrients were satisfactory considering the complexity of multiple processes working in Piranga River watershed.