Prediction of Flow-Rate of Sanaga Basin in Cameroon Using HEC-HMS Hydrological System: Application to the Djerem Sub-Basin at Mbakaou

This article proposes the development of a rainfall-runoff model in order to simulate the hydrologic behavior of the Djerem sub-basin at Mbakaou in the Sanaga basin in Cameroon. We suggest a solution based on a spatial conceptual modeling, then a restriction to a finite number of parameters judged applicable for the different choices of models. The approach relies on the hydrologic system HEC-HMS whose interest is not only it's adaptability to the tropical and equatorial climate, but also and especially to the acceptable results that it provides for a very weak quantity of data. In this work, we take into consideration the different aspects of modeling such as: surface flow, underground flows, direct runoffs, losses, as well as interactions between the surface and the base-flow of rivers. The results obtained allows the planning of the Mbakaou dam, consequently to increase the hydroelectric production on one hand and on the other hand, provide some exploitable information for dimensions of hydrologic works, protective against floods or for hydrologic management and ecology of the Djerem basin at Mbakaou. To validate our model, a comparison of the simulated flow-rate and the observed flow-rate was carried out using historic data with the Nash-Sutcliffe Criterion and we obtained an efficiency of 0.862, meaning that the simulation was good.