Tidal propagation in Ria de Aveiro lagoon, Portugal

Ria de Aveiro is a shallow vertically homogeneous lagoon, located in the No rthwest of Portugal, connected to the Atlantic through a very narrow artifi cial channel, and supplied with freshwater by two major rivers, Antua and V ouga. The present study describes the application of a two-dimensional dept h integrated mathematical model, to predict tide-induced water level and de pth mean current for the entire lagoon. The model computes time series of t hose variables as well as their instantaneous distribution at different tim es of the tidal cycle. Properties of tides and tidal currents in Ria de Ave iro are characterized and discussed. Special emphasis is given to the study of the hydrodynamic behaviour of the lagoon in extreme conditions of astro nomical tide forcing, considering spring and neap tide conditions. Tides pr opagate from the mouth of Ria de Aveiro and are present in the entire lagoo n. The tidal amplitude decreases with the distance from the mouth while the phase lag in the high and low water (which is different) increases. The ti dal range increases for the spring tide at the far end of the channels corr espond to a local increase of the high tide level, which result in a fortni ghtly variation of the mean levels at those places. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.