Study of the dynamic behaviour of the Sancti Petri Channel, southwest coast of Spain

Abstract

The dynamic behaviour of the Sancti Petri tidal channel (southwest coast of Spain), which is open at both ends and connected to water bodies with different dynamic characteristics (Atlantic Ocean and Cádiz Bay), is studied herein. This singular estuary is characterized by double inflow-outflow extremes, the tide penetrating almost simultaneously through both ends with a small difference of amplitude. For this study, sea level recordings were obtained from different points throughout the channel and the corresponding harmonic constituents were determined. The results show that the phases of the semidiurnal tides increase from the mouths to a zone located in the vicinity of the channel´ s halfway point, while their amplitudes increase from the Atlantic Ocean to Cádiz Bay along the channel. A one-dimensional numerical model with geometry that is representative of the channel was used to reproduce the features observed for the semidiurnal and diurnal tidal constituents. The data supplied by the model were verified with values obtained at strategically chosen sites of the inner domain. The model developed may be used for operational predictions of tides in the study area, especially for the ports of Gallineras and Sancti Petri.