This work describes the steps required to construct a hydrodynamic model of the Guajará

The waterfront of Belém, the capital of Pará State, Brazil, has undergone a beautification process whereby a hydraulic embankment is being executed at a section located at the confluence of the Guamá River and the Guajará Bay. A two-way avenue and a leisure and tourist complex will be built on this filled area. Protection of the construction site may be required in order to minimize loss of material during the build up operation and it could serve to maintain the tourist complex as well. Other important point is the impact analysis of the construction on the global flow at the confluence of the Guamá River and the Guajará Bay. Thus, a two-dimensional hydrodynamic finite elements model is used to simulate the velocities in the region for three configurations, namely: the first with the natural configuration of the area; the second where the work area is being protected by one groin; and the third one with two groins. The flow simulation for flood tide or ebb tide showed that for flood tide the velocities are higher than those in ebb tide. The simulated velocities with the presence of groins are slower than those simulated with the natural configuration model. Thus, it shows the efficacy of the groins to slow down the currents' velocities. In addition, the groins could protect the section of the revitalized Belém shore. In a general way, the construction does not change the global flow in the region. Applicação de um modelo 2D tipo águas rasas para analisar o escoamento e o uso de espigões para proteger uma área do estuário do rio Amazonas RESUMOBelém, capital do Pará, passa por um processo de revitalização de sua orla, onde está sendo executado o aterro hidráulico de um trecho da confluência entre o rio Guamá e a baía do Guajará. Nessa área aterrada serão construídos uma avenida de mão dupla e um complexo de lazer e turismo. Para tanto, a proteção da obra pode ser necessária para se minimizar a perda de material durante a execução dos trabalhos e depois para a própria conservação do complexo turístico. Outro ponto importante é a análise do impacto do projeto no escoamento BLANCO, C. J. C.; MESQUITA, A. L. A.; SENA, M. J. S.; SECRETAN, Y. Application of a 2D shallow water model to analyze the flow and the use of groins to protect an area of the Amazon river estuary. Ambi-Agua, Taubaté, v. 4, n. 2, p. 10-20, 2009. (doi:10.4136/ambi-agua.82) 11 global da confluência entre o rio Guamá e a baía do Guajará. Assim, um modelo hidrodinâmico 2D via método dos elementos finitos é utilizado para simular as velocidades na região em três modelos: o primeiro com a configuração natural da área, o segundo protegido com espigões e o terceiro com o projeto implantado. Os campos de velocidade com e sem a presença da obra servem para caracterizar os impactos sofridos pelo escoamento natural no trecho considerado. A simulação do modelo protegido mostra a eficácia dos espigões em reduzir as velocidades das correntes. De maneira geral, a implantação do projeto não muda o escoamento global da região.Palavras-chave: Modelo hidrodinâmico...

1 2 3 4 5 Climate change and sea-level rise are likely to have a significant impact on the low-lying coastal areas of Brazil around the Amazon estuary. However, the huge river flows -equivalent to a fifth of the world's total -combined with strong tidal effects and complex coastal morphology make the design and analysis of future flood protection works particularly challenging. This paper reports on the development, calibration and application of a successful hydrodynamic model for a new flood embankment in the coastal city of Belém. The model uses a geographic information system and finite-element method to solve shallow water equations, and appears suitable for wider application in the Amazon estuary.

The need to manage water resources and the way they behave in the face of changes in land use are essential for managing a watershed. In this context, a large basin modeling tool was applied to simulate the flow regime of the Ibicuí River basin considering two land use scenarios. The results were used to analyze the changes in the maximum and minimum annual and monthly average flows. The greatest change in land use was the forest coverage reduction associated to agriculture land use. As a result, an increase in the average monthly flows and in the reference flow Q90 was verified. In some sub-basins, a significant modification in the reference Q90 flow and maximum flow was verified. The Mann Whitney test showed that the results were accurate. The results indicated that changes in forest coverage and land use have an impact in the flow regime in the Ibicuí Watershed. The procedure used in this research can be applied to simulate future scenarios of land use and its impacts in the sub-basin´s flow rates.