If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Oualidia lagoon, Morocco: an estuary without a river

$53.74 plus tax (Refund Policy)

Buy Article:


This study describes some physical oceanography features of an estuary maintained by fresh groundwater inflow. The mesoscale variability of currents, temperature and salinity are documented from moored current meter observations of 12 days duration at three stations. Current speeds exceeded 0.7m.s−1 during spring tides and decrease to 0.1m.s−1 during neap tides. Current directions followed the major channel axes, reversing by 180 degrees between the flood and the ebb tides. Harmonic analysis indicated that tidal currents were mainly semi-diurnal, with a predominance of the M2 harmonic, but included M4 and M6 sub-harmonics, possibly resulting from non-linear interactions of the flow with the shallow bottom and channel curvatures. Close to the lagoon entrance the water is of marine character but, further upstream, salinity decreased significantly. In the absence of river runoff, this decrease must result from some yet undisclosed underground freshwater inflow. The water renewal time estimated using the tidal prism method was at least two tidal cycles. Using the fresh-water fraction method, the groundwater inflow was estimated to be 2.3m3.s−1 at most. Coupled 2D hydrodynamic and advection-dispersion models (MIKE21) were then used to verify some renewal times. The tidally averaged renewal time for the whole lagoon was found to be 7 days, while the local renewal time at the upstream end of the lagoon was 25 days. Finally, an inverse modelling approach using MIKE21 was used to estimate the groundwater inflow required to produce the observed salinities. That inflow was found to be 0.25m3.s−1 for the period under consideration, showing that the tidal prism method gave flows that were far too high.


Document Type: Research Article

Publication date: January 1, 2005

More about this publication?
  • Co-Published by NISC and Taylor & Francis - Subscriber access available here
Related content

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more