Author(s): Oumaima Gharnate; Dalila Loudyi; Mohamed Chagdali
Linked Author(s): Dalila Loudyi
Keywords: Harbor agitation; North Atlantic of Morocco; Birkhoff; Boussinesq; MIKE 21
Abstract: The port of Jorf Lasfar is one of the major ports on the North Atlantic coast of Morocco. Substantial agitation inside the port area has been observed. Consequently, it has become imperative to reconsider this phenomenon within the general framework of improving the protection of the sheltered water bodies. Along the Moroccan coast, swell is generally unrelated to the weather on the coast. It is, most often, the consequence of barometric depressions passing between the Azores Archipelago and Iceland. North Atlantic swells are the most frequent. They come from the West to Northwest sector. Northern swells are often formed on the coast of Portugal, but they can also be generated by trade winds. South - West swells are often associated with local bad weather. The present work aims at studying the agitation in the port enclosures using two sources of data : Data from previous studies of the region and satellite data acquired from the National Meteorological Department. A comparison between two models of harbour agitation is presented. The first model is based on the Birkhoff equation (MIKE 21 EMS) obtained from the potential swell theory and the second is based on the Boussinesq equation (MIKE 21 BW). The work includes also simulations of sediment transport with Mike 21 using Mud transport Module in the Jorf Lasfar Harbor. MIKE 21 BW is based on the numerical solution of the time domain formulations of the equations of type Boussinesq, Madsen and al (1991, 1992, 1997a, b), Sorensen and Sorensen (2001) and Sorensen and al (2004). This model allows the Boussinesq-type equations to be solved using a flux formulation with improved frequency dispersion characteristics. The MIKE 21 EMS elliptical wave module, is based on the numerical solution of the so-called "gentle slope" wave equation originally derived by Birkhoff in 1972. This equation governs the motion of water harmonic waves of infinitesimal height, considered as linear waves, over a gently sloping bathymetry with arbitrary water depth. The impact of the domain and bathymetry characteristics on the choice of these two types of numerical models are highlighted. The model that best fits to our study is presented.