MODELING AND ASSESSMENT OF URBAN FLOOD RISKS: A CASE STUDY OF AGADIR, MOROCCO

Abstract

Urban floods are among the most threatening natural hazards to Moroccan cities, particularly in light of rapid urban expansion that often disregards the original courses of rivers and streams. This situation is compounded by inadequate stormwater drainage infrastructure, which is unable to cope with extreme climatic events. In this context, the present study assesses urban flood risks in the city of Agadir (lower Souss Valley), a city that remains continuously exposed to recurrent flood hazards. The HEC-RAS(5.0.4) model, specialized in two-dimensional hydraulic modeling, was employed to simulate flood-prone areas and flow velocities during flood events. To perform a spatial cartographic analysis, the modeling results were integrated into a Geographic Information System (ArcGIS 10.01) using the Arc Hydro extension, in order to delineate natural watercourses and identify high-risk zones within the urban fabric. The results revealed a concentration of risks in low-lying neighborhoods such as Hay Al Amal, Tamersit, Azrou, Al Qods, Derb Tissir, and Mohammed V Avenue. The study emphasizes the need to incorporate digital modeling outputs into future urban planning documents and to develop comprehensive management plans aimed at improving stormwater drainage networks and protecting residential and economic infrastructures. Beyond its local context, the research demonstrates the scientific relevance of coupling hydraulic models with GIS for flood risk assessment in North African cities, offering insights that can guide both policy design and climate risk management strategies