title: Investigation of groundwater behavior in response to oceanic tide and hydrodynamic assessment of coastal aquifers.
abstract: This study was based, firstly, on observations and analysis of water table level variations in the Plio-Quaternary and Hauterivian aquifers, Oualidia (Morocco), and secondly, on comparing this behavior to oceanic tidal variations. Recordings were made in the well located at 1318 m from the coast, where the two aquifers are in direct contact. This investigation was subdivided into two periods of 4 months each. Results showed a tidal influence on water table level within the well during semi-diurnal and monthly periods. Water table fluctuation periods were equal to 12 h 25 min identical to oceanic tide propagation period, while time lag between water levels was equal to 3 h 24 min. Moreover, results allowed aquifer diffusivity calculation through a confined aquifer model, which was equal to 6.20 m(2) s(-1) calculated from average value of water amplitude and to 40.6 m(2) s(-1) calculated from average value of time lag. In addition, tidal wave amplitude attenuation occurred exponentially with distance from ocean, which disappeared completely after 2000 m from coast.
authors.affiliation: Marine Geoscience and Soil Science Laboratory (URAC-45), Earth Sciences Department, Faculty of Sciences, University of Chouaïb Doukkali, El Jadida, Morocco. faahmed81@yahoo.fr.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Fadili
authors.affiliation: I2M UMR 5295 Laboratory, Environmental Civil Engineering Department, Bordeaux University, Bordeaux, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Malaurent
authors.affiliation: Marine Geoscience and Soil Science Laboratory (URAC-45), Earth Sciences Department, Faculty of Sciences, University of Chouaïb Doukkali, El Jadida, Morocco.
authors.forename: Saliha
authors.initials: S
authors.lastname: Najib
authors.affiliation: Marine Geoscience and Soil Science Laboratory (URAC-45), Earth Sciences Department, Faculty of Sciences, University of Chouaïb Doukkali, El Jadida, Morocco.
authors.forename: Khalid
authors.initials: K
authors.lastname: Mehdi
authors.affiliation: I2M UMR 5295 Laboratory, Environmental Civil Engineering Department, Bordeaux University, Bordeaux, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Riss
authors.affiliation: Water and environment laboratory, Faculty of Sciences, University of Chouaïb Doukkali, El Jadida, Morocco.
authors.forename: Abdelhadi
authors.initials: A
authors.lastname: Makan
authors.affiliation: Marine Geoscience and Soil Science Laboratory (URAC-45), Earth Sciences Department, Faculty of Sciences, University of Chouaïb Doukkali, El Jadida, Morocco.
authors.forename: Khadija
authors.initials: K
authors.lastname: Boutayeb
mesh_terms: D004784:Environmental Monitoring; D060587:Groundwater / Q000032:analysis*; D057446:Hydrodynamics; D008962:Models, Theoretical; D009018:Morocco; D012623:Seawater; D013995:Time
keywords: Costal aquifers; Hydraulic diffusivity; Morocco; Oceanic tide; Oualidia