Impactos das atividades antrópicas na qualidade da água da bacia hidrográfica do rio Vacacaí Mirim – RS

• Autor(a) principal: Souza, Marielle Medeiros de
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• dARK ID: ark:/26339/001300000mfr9
• Texto Completo: http://repositorio.ufsm.br/handle/1/19499
• topic: Simulação hidrológica; Oxigênio dissolvido; Demanda bioquímica de oxigênio; Monitoramento fluviométrico; Hydrological simulation; Dissolved oxygen; Biochemical oxygen demand; Fluviometric monitoring; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL

This study was carried out to analyze the impacts of anthropogenic activities on the water quality of the Vacacaí Mirim river basin, located in the municipality of Santa Maria - RS, which is a tributary of the dam (or reservoir) to supply the municipality. In relation to the sum of the exposed soil / field (22.71%), agriculture (31.93%) and urban area (11.89%), the percentage of soil degrading activities in the river basin is high and 66.53 %. The water quality parameters of total organic nitrogen, total organic phosphorus, sediments and biochemical oxygen demand (BOD5,20) were evaluated by point and diffuse sources using the Soil and Water Assessment Tools (SWAT) model. The loads and concentrations of these parameters were obtained through water quality monitoring carried out in the period from 2010 to 2012, considering spatial information on land use and occupation, population estimate of the river basin affluent to the reservoir and measured flow along 2008 to 2012, obtained by means of the key curves also monitored in fluviometric sections installed in the tributary rivers of the reservoir. Inadequate management of soil with cropping areas, lack of planning and lack of practices to control runoff have led to increased nitrogen, phosphorus and sediment sources. Undue occupations such as: disorderly urbanization in sloping areas and permanent preservation, agriculture and livestock in inappropriate areas and without conservation practices, the removal of native vegetation (headland deforestation, water dividers, removal of riparian forest) have contributed to the deterioration of the area and caused the increase of nitrogen, phosphorus and sediment sources.