Inundation models of a potential tsunami in the plain of Martil-Tetouan (Morocco)

International audienceThe Mediterranean coast of Morocco would by highly vulnerable if a tsunami occurred in consequence of the complex geodynamic of the Alboran sea basin. In the plain of Martil and Tetouan, in the south-east of the Gilbraltar strait, life is intrinsically linked to the touristic attractiveness which represents the first economic sector locally. Therefore, the occupation of the coast and its real estate is seasonal. A tsunami constitutes a latent threat for this developing coastal environment which the tourist numbers strongly change the extent of the exposition of population between high and low season.Protecting these human and material issues leads to increase the interest about the question of tsunami risk that is still unexpressed in the national natural risks governance (OCDE, 2016). This, using modelling tools can enhance risk apprehension by public authorities (civil protection, urban planners, etc.) and improve the awareness of resident and seasonal populations.The chosen approach to study the tetouanese coast relies on the comparison of three inundation modelling methods. The static model consists of subtracting a given water height to the local topography. The dynamic model uses numerical simulation with the Freshkiss3D computing code to appreciate the progression of the tsunami in the plain. Finally, the hybrid model subtracts the total volume of water arriving at the coast by elevation level.Their comparison highlights the heterogenous exposition of the territory. Lower and densely populated areas will need a strengthened attention in terms of evacuation planning. The spatial inundation extent obtained also lead to a precise identification of the issues exposed to the risk of tsunami, with the use of demographic criterion and a sectorial economic analysis, but mostly by analysing the capacity response of the crisis management entities in case of a tsunami