The use of hydraulic models to optimize the rehabilitation of an open channel irrigation system: The example of the Senegal river delta irrigation system

摘要

For more than thirty years, important investments have been undertaken for hydro-agricultural schemes in the Senegal River Delta. Indeed, the River's distributaries form a complex network of natural side channels with a high potential in terms of land suitable for irrigation. However,the current configuration of these channels and the lack of maintenance prevent this feeder system from conveying the flows required to meet the region's agricultural production potential. Consequently their rehabilitation has started. This takes into account the future water demand,the network's geometrical characteristics, the actual practice of irrigation, as well as the type of control used for managing the system and has led to the use of a mathematical model for design purposes: the Simulation of Irrigation Canals (SIC) software, developed by Cemagref. The SIC software has been chosen because it accommodates the simulation of automatic gates and performs transient state runs particularly well. Steady state runs do not take into account decisive factors like diurnal irrigation or the significant storage capacity of the system, and would lead to a flawed design of the system. This article illustrates the advantages of using the transient regime for the design of a networked feeder system with substantial storage capacity