Afra, Abdallah2026-05-132026-05-132025-12-20https://dspace.univ-tlemcen.dz/handle/112/26323This PhD dissertation examines flood risk assessment in Algeria's Mekerra Basin utilising an advanced Rainfall-Runoff-Inundation (RRI) modelling methodology to overcome significant deficiencies in flood prediction and management for semi-arid locations. The research establishes an extensive hydrological modelling framework that incorporates high-resolution topography data, land use patterns, and historical climate records to simulate and forecast flood dynamics under present climatic scenarios. The RRI model exhibits robust predictive performance (NSE > 0.86, R² > 0.89) in accurately representing the basin's distinctive flash flood behaviour, as evidenced by thorough calibration and validation against recorded flood events. This research not only advances the field of semi-arid hydrology but also offers policy recommendations that bolster Algeria's national flood risk reduction strategies, while creating a transferable methodology applicable to other data-scarce regions susceptible to heightened flood risks due to climate change. The results underscore the pressing necessity for adaptive water management strategies that integrate sophisticated modelling methods with community-driven mitigation efforts to improve resilience in the Mekerra Basin and similar semi-arid watersheds globally.enflood modelingRainfall–Runoff–Inundation (RRI) modelMekerra Basinflood risk assessmentsemi-aridThesis