Water quality modelling for the ecosystem of the Ciénaga de Tesca coastal lagoon

A water quality model for shallow eutrophic lagoons is proposed. The model consists of a 2-D hydrodynamic and a chemical-biological blocks and is an intermediate variant between the self-purification models, usually used in the engineering practice, and the eutrophication models. The advanced engineering parts are: (1) the grid and subgrid hydrodynamic formulation; (2) the anthropogenic and natural organic matter fluxes; and (3) relations between the phytoplankton productivity and the conditions of the nutrients and light. The model was calibrated and applied for the Ciénaga de Tesca shallow lagoon (Colombia). Results, obtained by means of numerical simulations, are considered as possible alternatives to improve the ecological state of the Ciénaga de Tesca. Engineering dignities of the model are coupled in a minimum available hydrobiological information that is needed and the representation of model results.