POLLYANNA FARIA NOGUEIRA
Abstract:
Demand for water use resources has been gradually increasing and, as a result, the effects of anthropogenic activities on water bodies. The waters of the Claro river, in Goiás state, have been using for hydroelectric power generation, between the cities of Jataí, Caçu and Cachoeira Alta, from the construction of hydraulic projects. With this comes the importance of developing mitigation measures in relation to water quality and reservoir silting, so that all investments are not lost, as water resources are invaluable to the environment, as well as indispensable for economic development, political and social. Based on this, the present work aimed to frame the water body and evaluate the quality in the reservoir area of the Foz do Rio Claro Hydroelectric Power Plant (HPP) through limnological parameters. The parameters evaluated were: Water Temperature (T), Dissolved Oxygen (OD), Total Dissolved Solids (TDS), Chlorophyll (CHL); Total Phosphorus (PT), Secchi Transparency (transp) and Turbidity (turb). Twenty-three sampling points were defined along the longitudinal axis of the reservoir to cover all aquatic compartments (river, transition and lake). The reservoir water framework was defined according to CONAMA resolution 357/2005. The trophic state of the waters was evaluated from the Trophic State Index (EIT). Water samples were collected in four periods, with an interval of six months, covering distinct climatic periods of the Brazilian Cerrado. According to the data evaluated in relation to CONAMA resolution 357/2005, the parameters OD and PT presented values that framed the waters in classes 3 and 4 in the rainy season. Based on the TDS, CHL and Turb data, the reservoir waters fall between classes 1 and 2. It was possible to detect a high eutrophication level for the Foz do Rio Claro Reservoir. Based on the data for the EIT parameters CHL was classified as supereutrophic, phosphorus as oligomesotrophic, Secchi was varied, the EIT for January 2013 mesoeutrophic, January 2014 eutrophic and July 2013 mesoeutrophic, and August 2014 Ultraoligotrophic, Oligotrophic and Mesotrophic. Being verified that the periods did not present relation to each other. For the collections made in January, possibly due to the influence of precipitation in the basin that ends up carrying a higher nutrient load to the reservoir waters, while in the collections performed in July 2013 and August 2014, the waters can be classified between ultraoligotrophic and mesotrophic.
