ABSTRACT
ABSTRACT: Flooding is a devastating natural threat which impacts different regions across the world every year. These extreme hydrological phenomena are increasing in terms of their occurrence times and damage intensity due to human activities and climate change. The aim of this study therefore simulates the rainfall-runoff process applying 24-h storm rainfalls to predict design peak discharge for the 200, 100, 50, 20, 10, and 5 year return, on the Meghouga river basin located in Tangier city (North of Morocco). In this study, the Soil Conservation Service Curve Number (SCS-CN) model based on the soil type and land use data was used through The Hydrologic Engineering Center-Hydrologic Modeling System software (HEC-HMS, version 3.5) to simulate the storm event to set up the rainfall-runoff model in Meghougha basin, this model provides a various meteorological and hydrological processes to obtain flood hydro-graph. SCS Unit Hydrograph (SCS UH) method was applied for the rainfall-runoff transforma-tion computation while SCS Curve Number method was used for loss infiltration. The results obtained in the course of this study consist on unit hydrographs which generates the rainfall in function of the runoff for watershed outlet as well as the estimation of runoff for different re-turn periods where no gauge station is available.
