Name: Lara Rupf Reis
Type: MSc dissertation
Publication date: 09/10/2017
Advisor:
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Role |
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Antonio Sérgio Ferreira Mendonça | Advisor * |
Examining board:
Name![]() |
Role |
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Antonio Sérgio Ferreira Mendonça | Advisor * |
Davi Gasparini Fernandes Cunha | External Examiner * |
Edmilson Costa Teixeira | Internal Examiner * |
Summary: Reservoir formation, through dam construction, modifies watercourses residence times and quality. The aim of this work is the understanding of reservoirs effects on dammed watercourses water quality parameter values and indexes, and trophic state indexes. Limnological monitoring results were analyzed for upstream, inside and downstream points of Alegre Small-sized Hydropower Plant reservoir, located in Alegre river watershed, and Mascarenhas Medium-sized Hydropower Plant reservoir, located in Doce river watershed, both in Espírito Santo State, Brazil. Water quality parameters were analyzed and water quality indexes were calculated by using CETESB, NSF and CWQI models. Trophic status classification was carried out through Lamparelli and Cunha models application. Several water quality parameters and indexes for points related to Alegre Hydropower Plant were worse than those observed for points related to Mascarenhas Hydropower Plant due, mainly, to the lower Alegre river self-purification capacity and to the fact that Alegre Hydropower Plant is located inside an urban area without wastewater treatment infrastructure. From the results, it can not be affirmed that the water passages through the studied reservoirs have resulted in Alegre and Doce rivers water quality significant improvements. This fact may be related to the reservoirs small residence times, which led to classification of their environment as predominantly lotic. For all Trophic State Indexes models studied, the Alegre reservoir downstream point presented higher trophic levels than those obtained for the points located inside and upstream. For the Mascarenhas reservoir, the downstream point presented the lowest trophic indexes values. It was also concluded that CWQI is more versatile than CETESB and NSF indexes and that the use of water quality indexes for general quality classification, regardless of water intended uses, may lead to erroneous conclusions, indicating better conditions than the actual ones.