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

Abstract

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.