Abstarct: Meander straightening (or rectification), one of the most severe forms of river channelization, shortens channel length, increasing slope and reducing flood heights. However, rectification also destabilizes the river’s equilibrium or grade by increasing sediment transport capacity limited to the rectified reach. If we rectify a river, this rectification reduces angular coefficient of river, creating horseshoe lakes and producing many changes in river morphology. In addition to changes in slope, velocity and discharge, the ecosystem of area undertakes changes that even leading to create a new ecosystem or destroying the ecosystem of that area. In this thesis, a numerical model is written in visual basic to validate this simulation with resultant objective data in the studies of Parker, Talbot and Lapointe to facilitate highway construction along the Sainte-Marguerite River and compared to Talbot and Lapointe simulations using SEDROUT2.0 our simulation results show higher accuracy that is closer the data presented by Parker.