Análise da influência da descarga do rio Santa Maria da Vitória sobre a propagação da onda de maré e da hidrodinâmica tridimensional da Baía de Vitória

• Autor(a) principal: Nascimento, Thiago Freitas do
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/10294
• topic: Maré barotrópica; MOHID (Modelo hidrodinâmico); Simulação numérica; Engenharia Sanitária; Estuários; Vitória, Baía de (ES); 628

The tidal wave is damped in estuarine regions and progressively distorted by frictional forces in the bottom, by river discharge, by narrowing/abrupt enlargements in the channels and by the presence of vegetation areas. In this paper the study is conducted to understand the induced tidal wave along the Porto de Vitória and check the river discharge influence of the Rio Santa Maria da Vitória in hydrodynamics. The hydrodynamic model used in this work is MOHID in three-dimensional barotropic mode and deployed throughout the estuarine system of the Ilha de Vitória. And the simulation period corresponds to the year 2009. As the tidal boundary condition, the model was forced by a set of harmonics, which were extracted from a long series of tidal data by Pacmaré program. And the data of river discharge of Santa Maria da Vitoria were obtained from the National Water Agency (ANA) website. As a boundary condition in the bottom was used length values equivalent roughness, which were extracted from the maps of study by Paiva (2008). While the mangrove region the value of 3 meters was used, as the work of Maciel (2004) and Nascimento et al. (2011). A rectangular mesh horizontally at regular intervals of approximately 56x56 meters was used, while for the vertical discretization a mesh sigma type was used with 10 layers. The results founded for the tide waves in the Baía de Vitória was observed that the tidal wave to propagate upstream of the estuary, the M2 and S2 components has a different behavior, while the first is amplified the second is reduced. Moreover, the region of Baía de Vitória is where the shallow water harmonic suffers more influence. During periods of high river discharge the tidal wave tends to be blocked, resulting in a number of harmonics and amplitude lower compared with periods of low river discharge, corroborating the results of Goring (1984), Godin (1985); Nicoliti (2007); Nicoliti et al. (2009). It was ascertained that at least 11 harmonic constituents are common to the period of low river discharge, are absent in the period of high river discharge analyzed. For the period low river discharge, we realized the presence of multiple vortices when analyzing residual streams and these vortices no was noted in the period of high river discharge. Thus, it was found that during periods of high river discharge the water quality of the estuarine system of Ilha de Vitória may suffer a substantial improvement. However, when we analyzed the hydrodynamics of the Baía de Vitória, it was found that there is a phase difference between the northern and southern parts, and the highest velocities are found in the southern part of the bay, which is aligned with the work done by Garção (2007) and Rigo (2004). However, during high river discharge events the northern part of the bay runs like a river, flowing in one direction throughout the tidal cycle, and it is in this region where the highest velocities are found. Finally, a reversal of dominance was observed in the region, in the periods of spring tide the estuary is ebb dominant and in the periods of quadrature the estuary is flood dominant, these result also was found by Rigo (2004). Furthermore, it was noted that during low tide the highest velocities are found in the subsurface in central region of Baía da Vitória.