masterThesis
Impactos do esgotamento hídrico na qualidade da água de um reservatório da região semiárida tropical em evento de seca prolongada
Fecha
2017-11-22Registro en:
LEITE, Jéssica Nayara de Carvalho. Impactos do esgotamento hídrico na qualidade da água de um reservatório da região semiárida tropical em evento de seca prolongada. 2017. 25f. Dissertação (Mestrado em Engenharia Sanitária) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2017.
Autor
Leite, Jéssica Nayara de Carvalho
Resumen
In dry regions, many reservoirs reach volumes so low that they are no longer sufficient for supply, interrupting the water intake. In the Brazilian semi-arid region, occasional drying is recurrent in some reservoirs, which remains dry for months or even years, representing a problem for the supply and causing socioeconomic issues. After an event of drying, in terms of impacts on water quality, it is expected that there will be improvements after reflooding: Less algal biomass, increased water transparency, decreased turbidity and low concentration of nutrients. The aim of this study was to analyze the water quality of a tropical semi-arid reservoir after drying during an extended drought event. The studied reservoir was Dourado, located in the Brazilian semi-arid. This study consists of the comparison of three distinct periods accordingly to the water volume. Those periods were marked by rainfall below the annual historical average, therefore being inserted in an extended drought period. The variables water transparency, turbidity, electrical conductivity, pH, total phosphorus, soluble reactive phosphorus and chlorophyll-a were analyzed. After the water renewal, a significant reduction in chlorophyll-a, indicative of algal biomass, indicates an improvement in water quality in terms of eutrophication, due to the change of the trophic state from eutrophic to mesotrophic. pH, electrical conductivity and turbidity variables also reduced after the reflooding, indicating an improvement in water quality. There was no reduction in total phosphorus and soluble reactive phosphorus after the reflooding in comparison to the previous periods.