Case Study: Promoting the Stability of the Óbidos Lagoon Inlet
Publication: Journal of Hydraulic Engineering
Volume 133, Issue 7
Abstract
The stabilization of tidal inlets by jetties interrupts the littoral drift and has negative visual impacts. This paper proposes an innovative solution to improve the stability of a tidal inlet (the Óbidos Lagoon, Portugal) and minimize maintenance dredging, while avoiding the disadvantages of the traditional solution. The new solution has two key features. First, transverse channels are dredged over the tidal flats to promote ebb dominance, thereby improving the ability of the lagoon to flush out incoming sediments. Second, a partially submerged guiding wall near the southern shoreline, together with the existing guiding wall in the northern shore, prevents the movement of the inlet channel and concentrates the ebb flow in the channel. Analyses with empirical, numerical, and analytical models indicate that the solution improves the stability of the tidal inlet and reduces the accretion in the system.
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Acknowledgments
This work was funded by INAG, project “Revision of the environmental management plan for the Óbidos Lagoon” and LNEC, projects “Long-term evolution of estuarine morphology” and “Short-term morphodynamics of tidal inlets.” The writers would like to thank INAG for the permission to publish this work and Professor A.M. Baptista (Center for Coastal and Land-Margin Research, Oregon Health and Science University) for the model ELCIRC. The writers are also grateful to their colleagues who participated in the INAG project, Mr. J. Rego for his participation in the analysis of the hydrodynamics of the Óbidos Lagoon, and Mr. Lourival Trovisco for treating the aerial photographs.
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Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 133 • Issue 7 • July 2007
Pages: 816 - 824
Copyright
© 2007 ASCE.
History
Received: Jan 17, 2006
Accepted: Nov 30, 2006
Published online: Jul 1, 2007
Published in print: Jul 2007
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