Identification of Degradation Factors and hydraulic dysfunction of the Galmi irrigated scheme and measures for the sustainability of the system (Niger)

Niger is a country with a chronic food deficit despite the efforts made by successive governments. To address this, the government considered creating hydro-agricultural infrastructure in the 1970s, but these systems have been poorly maintained since their construction. It is within this context that the present study was conducted in the Galmi irrigation scheme. Its objective is to conduct a comprehensive diagnosis of the irrigation, protection, and drainage networks in order to identify the factors contributing to their degradation and the causes of their malfunction. The methodology involved surveying a number of canals within these various networks and conducting our diagnosis in relation to them. This study reveals that the factors contributing to the degradation of the Galmi irrigated area, leading to its poor hydraulic functioning, are numerous and multifaceted: the near-total silting up of the reservoir, the deterioration of the weirs, broken panels, silting, weed growth, and cracking of the canals. It is estimated that over 70% of the hydraulic structures within this irrigated area are degraded. Finally, we note the poor management of irrigation water, the failure to adhere to water rotation schedules, and the breach of the protective dike. For a successful return to irrigated agricultural activities, it would be advisable to rehabilitate this, the country's largest irrigated area.