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- Hydrodynamic model intercomparison for the patos lagoon (Brazil)Publication . Martins, Flávio Augusto Bastos da Cruz; Fernandes, Elisa H. L.An intercomparison study is carried out between two models with different formulations and spatial discretizations in order to overcome the limitations posed by the standard calibration and validation procedures and improve confidence in the hydrodynamic results for the Patos Lagoon. Numerical simulations were carried out applying the TELEMAC and MOHID models, based on the same boundary conditions and identical calibration coefficients so differences in calculated flow conditions result from the formulations and parameterizations of each model. Results from both models are compared with measurements from three stations inside the lagoon. Preliminary results indicate that both models compare well with the measurements and with each other. These results increase the confidence on hydrodynamic results for the Patos Lagoon and provide the first step towards water quality studies for the area.
- Coupling anchovy eggs and hydrodynamic model as an assessement tool for estuarine ecohydrological managementPublication . Morais, P.; Chicharo, Maria Alexandra; Martins, Flávio Augusto Bastos da Cruz; Chícharo, Luís; Lopes, J.Nitrate and urban waste water directives have raised the need for a better understanding of coastal systems in European Union. The incorrect application of these directives can lead to important ecological or social penalties. In the paper this problem is addressed to Ria Formosa Coastal Lagoon. Ria Formosa hosts a Natural Park, important ports of the southern Portuguese coast and significant bivalve aquaculture activity. Four major urban waste water treatment plants discharging in the lagoon are considered in this study. Its treatment level must be selected, based on detailed information from a monitoring program and on a good knowledge of the processes determining the fate of the material discharged in the lagoon. In this paper the results of a monitoring program and simulations using a coupled hydrodynamic and water quality / ecological model, MOHID, are used to characterise the system and to understand the processes in Ria Formosa. It is shown that the water residence time in most of the lagoon is quite low, of the order of days, but it can be larger in the upper parts of the channels where land generated water is discharged. The main supply of nutrients to the lagoon comes from the open sea rather than from the urban discharges. For this reason the characteristics and behaviour of the general lagoon contrasts with the behaviour of the upper reaches of the channels where the influence of the waste water treatment plants are high. In this system the bottom mineralization was found to be an important mechanism, and the inclusion of that process in the model was essential to obtain good results.
- Modelação matemática tridimensional de escoamentos costeiros e estuarinos usando uma abordagem de coordenada vertical genéricaPublication . Martins, Flávio Augusto Bastos da Cruz
- A three-dimensional hydrodynamic model with generic vertical coordinatePublication . Martins, Flávio Augusto Bastos da Cruz; Neves, R.; Leitão, Paulo ChambelA three-dimensional primitive equation model and its application to a tidal estuary is described. The model solves the primitive equations for incompressible fluids with Boussinesq and hydrostatic approximations. The discretization is based on the finite volume method and allows a general vertical coordinate. The computational code is implemented in such a way that different vertical coordinates can be used in different parts of the domain. The model was designed to be able to simulate the flow both in the open ocean and in coastal and estuarine zones and can be coupled in a simple way to ecological models. The model was implemented successfully in several estuarine and coastal areas. Results are show for the Sado estuary in Portugal to illustrate model accuracy and potential. Quantitative validation is based on field data (water levels and velocities) while qualitative verification is based on the analysis of secondary flows.
- A coupled hydrodynamic and ecological model to manage water quality in Ria Formosa coastal lagoonPublication . Martins, Flávio Augusto Bastos da Cruz; Pina, Pedro; Calado, S.; Neves, R.Nitrate and urban waste water directives have raised the need for a better understanding of coastal systems in the European Union. The incorrect application of these directives can lead to important ecological or social penalties. In this paper this problem is addressed to Ria Formosa Coastal Lagoon. Ria Formosa hosts a Natural Park, important ports of the southern Portuguese coast and significant bivalve aquaculture activity. Four major urban waste water treatment plants discharging into the lagoon are considered in this study. Its treatment level must be selected, based on. detailed information from a monitoring program and on a good knowledge of the processes determining the fate of the material discharged into the lagoon., In this paper the results of a monitoring program and simulations using a coupled hydrodynamic and water quality/ecological model, MOHID, are used to characterise the system and to understand the processes in Ria Formosa. It is shown that the water residence time in most of the. lagoon is quite low, of the order of days, but it can be larger in the upper parts of the channels where land generated water is discharged. The main supply of nutrients to the lagoon comes from the open sea rather than from the urban discharges. For this reason the characteristics and behaviour of the general lagoon contrasts with the behaviour of the upper reaches of the channels where the influence of the waste water treatment plants are high. In this system the bottom mineralization was found to be an important mechanism, and the inclusion of that process in the model was essential to obtain good results.
- Modelação hidrodinâmica de escoamentos costeirosPublication . Martins, Flávio Augusto Bastos da Cruz; Neves, R.; Chambel, PauloAs zonas costeiras, os estuários e os sistemas lagunares são regiões de elevada importância do ponto de vista económico devido à intensa actividade nelas desenvolvida. Encontram-se por esse motivo sujeitas a fortes pressões do tipo ambiental. A correcta gestão dos seus recursos deve ser apoiada em ferramentas que possibilitem uma análise precisa dos fenómenos que nelas ocorrem e permitam a previsão da evolução desses sistemas. A recente evolução na capacidade de cálculo dos computadores de pequeno porte tornou viável a utilização de modelos hidrodinâmicos como ferramentas de apoio à decisão.
- Modelling antropogenic impact on primary production of sado estuaryPublication . Martins, Flávio Augusto Bastos da Cruz; Neves, R.; Pina, PedroThe assessment of human impact on complex estuarine systems is a multidisciplinary task that is highly demanding in terms of measurements and fieldwork. Nowadays the use of inexpensive and reliably modeling tools can substantially reduce the amount of measurements needed to characterize a system. These tools are also a convenient way to forecast the future evolution of the system and to study the impact of different scenarios of human influence. In this communication a modeling system composed by hydrodynamic, transport and ecological models is used to assess the current trophic state of Sado Estuary (Portugal) and to predict the future trends of the system based on different scenarios of human intervention. Special care is taken to the impact of changing riverine nutrient loads. Sado estuary is a large European estuary that has been considered until now in good trophic conditions with eutrophication appearing only in some isolated spots. Nevertheless in recent years some studies point out that the situation is changing. Sado estuary is a system with strong environmental opposing interests. It hosts a major industrial and urban center around the city of Setúbal and the upper reaches are used to intensive cultures such as rice. On the other hand the estuary possess an important ecological value since it is used by several important species of fish as a spawning and nursery area and it’s wetlands are used by many species of birds as winter shelters. Due to it’s importance the majority of Sado Estuary is considered as Natural Reserve.