Banca de DEFESA: JÉSSICA NAYARA DE CARVALHO LEITE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA NAYARA DE CARVALHO LEITE
DATA : 22/11/2017
HORA: 13:15
LOCAL: Auditório do Centro de Tecnologia (CT/UFRN)
TÍTULO:

IMPACTS OF OCCASIONAL DRYING DURING AN EXTENDED DROUGHT ON THE QUALITY OF THE WATER OF A RESERVOIR IN A TROPICAL SEMI-ARID REGION

PALAVRAS-CHAVES:

Shallow artificial lakes. Extended drought. Water level fluctuation. Chlorophyll-a.

PÁGINAS: 26
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Sanitária
RESUMO:

Reservoirs are artificial ecosystems built mainly in regions whose water bodies are scarce or insufficient to attend the demands of use. In dry regions, many reservoirs reach volumes so low that they are no longer sufficient for supply, interrupting the water intake. In the northeastern semi-arid region, occasional drying is recurrent in some reservoirs, which remains dry for months or even years, representing a huge problem for the supply and causing numerous socioeconomic issues. After an event of drying, in terms of impacts on water quality, it is expected that there will be improvements after reflooding from precipitation: Less algal biomass, increased water transparency, decreased turbidity and low concentration of nutrients. The objective of this study was to analyze the water quality of a tropical semiarid reservoir after drying during an extended drought event. The studied reservoir was Dourado, located in Currais Novos, Rio Grande do Norte, Brazil. The study took three distinct periods, determined according to the water volume. The three study periods were marked by rainfall below the annual historical average and, then being inserted in an extended drought period. The variables water transparency, turbidity, electrical conductivity, pH, total phosphorus, dissolved reactive phosphorus and chlorophyll-a were analyzed. After water renewal, the main result in terms of the improvement of the water quality of Dourado is the reduction of phytoplankton biomass. With this reduction, the reservoir turned to be considered as mesotrophic, considering only the chlorophyll-a variable. However, despite of the significant reduction in algal biomass in the period after the reflooding of Dourado, there was no significant reduction in nutrient concentration, thus, no improvement in water quality in terms of eutrophication occurred. The high concentration of nutrients in Dourado is probably related to the use and occupation of its watershed, as well as to the absence of management of the drainage basin and sediment of the reservoir.

MEMBROS DA BANCA:
Externo ao Programa - 2190974 - JOANA DARC FREIRE DE MEDEIROS
Externo à Instituição - JOSÉ ETHAM DE LUCENA BARBOSA - UEPB
Presidente - 1764855 - VANESSA BECKER