Modeling of the marine circulations and contamination by wastewater in the Nador lagoon

In this paper, marine circulations and transport of wastewater in the Nador lagoon, considering the new inlet with Mediterranean Sea, are simulated by the finite volume method. The physical model is based on the well known 2D shallow water equations that include slope variations and friction losses. Convection fluxes are approximated by a second order Non Homogeneous Riemann Solver (SRNH) on unstructured meshes, whereas an operator splitting procedure is used for the friction terms. The solver can be applied to model flows on complicated geometries and can handle slope variations while preserving the balance between the pressure gradient and the bed source term. Results show clearly the presence of recirculation zones inside the lagoon. In addition, it is found that the flow is almost inert at Beni Enzar and Kariat Arkmane which leads to a contamination and a stagnation of the wastewater in these regions.