Banca de DEFESA: CARLOS ALBERTO NASCIMENTO DA ROCHA JUNIOR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : CARLOS ALBERTO NASCIMENTO DA ROCHA JUNIOR
DATA : 25/06/2018
HORA: 14:30
LOCAL: Auditório da Eng. Ambiental - Sala 212 (CTEC/UFRN)
TÍTULO:

EFFECTS OF VOLUME VARIATION AND LIGHT AVAILABILITY ON TEMPORAL DYNAMICS OF PHYTOPLATLANTIC BIOMASS IN A SEMIARID TROPICAL RESERVOIR

PALAVRAS-CHAVES:

Eutrophication. Models. Hydrical stress. Light availability.

PÁGINAS: 32
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Sanitária
RESUMO:

Eutrophication of aquatic ecosystems is one of the main causes of deterioration of water quality and has as main consequence the excessive growth of algae. The variation in algal biomass due to the eutrophication process is mainly dependent on the availability of water resources, such as light and nutrients, but it is also influenced by the fluctuation in water volume. In this sense, it is of fundamental importance to understand the main factors that influence the phytoplankton community, in order to predict the dynamics of their biomass for the improvement of the management of lacustrine ecosystems. Most of models that try to explain the variation of the phytoplankton biomass were developed for temperate environments and with high water availability, and the studies are focused on tropical environments with low water availability. Thus, the objective of this research is to explain and predict, through a model, the dynamics of algal biomass in a tropical semiarid reservoir, assuming that light availability and volume variation are the main factors limiting the growth of phytoplanktonic biomass. The proposed model related the effects of the reduction of the volume of water stored in the reservoir and the availability of light on phytoplankton growth, admitting a predominance of the cyanobacteria Cylindrospermopsis raciborskii species in the phytoplankton community. The results showed that the simulation tended to follow the behavior of the data observed during the monthly monitoring performed in the reservoir between the years 2010 and 2014, with an increase in chlorophyll a concentrations (CHLA) as the stored volume decreases. In addition, the peak occurrence in the light attenuation rate is derived from a sharp fall in simulated CHLA. This study shows that light availability along the water column and hydrological events affect algal growth, thus showing evidence that these are its main limiting factors, at least during periods of extreme drought such as the period analyzed in this study.

MEMBROS DA BANCA:
Presidente - 1362202 - JOSE LUIZ DE ATTAYDE
Interno - 1764855 - VANESSA BECKER
Interno - 2190974 - JOANA DARC FREIRE DE MEDEIROS
Externo à Instituição - CARLOS RUBERTO FRAGOSO JUNIOR - UFAL