Localização de áreas de monitoramento telemétrico em ambientes aquáticos da Amazônia / Location of telemetric monitoring sites in Amazon floodplain lakes

O presente trabalho demonstra a aplicabilidade de imagens de sensoriamento remoto e de métodos de processamento de imagens digitais para definição de locais adequados à instalação de sistemas telemétricos de monitoramento de variáveis ambientais em sistemas aquáticos, localizados em regiões de difícil acesso. A técnica consiste essencialmente da aplicação de operações Booleanas entre mapas da pluma do Rio Amazonas e de zonas inundadas do Lago de Curuai em diferentes etapas do ciclo hidrológico. A localização exata para o sistema de monitoramento telemétrico será vital para o desenvolvimento de modelos de troca de gases traço entre a planície de inundação Amazônica e a atmosfera.

The present work illustrates the application of remote sensing and image processing methods to define appropriate sites for installing buoy moored telemetric systems at the surface of Amazon floodplain lakes for long-term limnologic-micrometeorologic monitoring. The technique consists essentially of Boolean operations over Amazon plume maps and historic inundation of the Curuai Lake at distinct stages of the hydrologic cycle. The precise location for the long-term monitoring is vital to the development of models concerning air-water trace gas exchange in the Amazon floodplains.

Emissão de metano por reservatórios hidrelétricos amazônicos através de leis de potência / Methane emission of Amazonian hydroelectric reservoirs from Powerlaw relations

The purpose of this work is evaluating methane emissions from two Amazonian reservoirs, Tucuruí and Samuel. The analysis considers fluctuations of the reservoir area-height and isotopic measurements and fluxes of d13CH4 acquired in the field, which are influenced by many factors simultaneously, such as winds, atmospheric pressure, oxidation in the water column, and others. Isotopic composition of methane in bubbles indicates that CO2 reduction is a major pathway for methane production in the sediments. The results also show that fluxes are higher in shallow reservoirs than in deeper ones. Using concepts and techniques of fractal theory, fundamentally based on power law functions, and considering a time horizon of 100 years, a model between water level, flux and reservoir area of Tucuruí allowed to estimate methane emission from Tucuruí at about 2,5 ± 2,7 x 10