Flood risk vulnerability assessment using GIS and hydraulic modeling, case study of the Fez river watershed, Morocco

¹ Research group water sciences and environmental engineering, Geoengineering and Environment Laboratory, Department of Geology, Faculty of Sciences, Moulay Ismail University, Zitoune, B.P11201, Meknes, Morocco.
² ITC-CNR, Construction Technologies Institute, National Research Council, 70124 Bari, Italy;
³ National Institute for Scientific and Technological Research in Water, University Ibn Zohr – Agadir.
⁴ Geography and Tourism Research Group, Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001 Heverlee, Belgium.

^* Corresponding author: narjisse.essahlaoui@edu.umi.ac.ma

Abstract

Morocco, like other countries in the world, is threatened by floods. These have become frequent in previous years and the current year (2024). Weather-related floods in the Fez river watershed constitute the natural hazard that threatens property. In this work, we adopted an approach based on the modeling of flow processes using the HEC-RAS model. The main sources of information are topographic map, geological map, hydrometeorological data, digital terrain model (DTM), land use, etc. 2D and 3D hydraulic modeling using HEC-RAS software, allowed the mapping and analysis of floodplains. The HEC-RAS hydraulic modeling tool is used to perform permanent flow simulations and the model input files are developed in GIS software using the HEC-GeoRAS extension. The results of the study further indicate that the Geographic Information System combined with hydraulic modeling are very effective tools for floodplain mapping and analysis. The resulting map is the flood risk map. This useful information can be used to plan and control future floods and will thus help in sustainable land management.