Hydrodynamic investigation and numerical simulation of intermittent and ephemeral flows in semi-arid regions: Wadi Mekerra, Algeria

Abstract

Semi-arid regions are characterized by important infrequent rainfall. They often occur in early autumn and give rise to devastating floods. Flooding problems at Wadi Mekerra, located in the Sidi Bel Abbes town (Northwest Algeria), was traditionally the main concern of researchers and government officials. In this work, the magnitude of raging flood wave in the studied catchment and the principal causes are discussed. After this, we present the main hydromorphometric features and the results of numerical simulations of flood wave. This simulation is done by using finite volume shock capturing schemes. It concerns applying the first order Godunov scheme and the second order Monotonic Central scheme. The Manning roughness coefficient was used as a calibration parameter. The comparison of numerical results with observed data confirms more stability and accuracy of applied numerical schemes in rising limb phase than in the falling limb phase. These results provide information on flood forecasting and monitoring of changes in the magnitude of the flow in Wadi Mekerra.