Du barrage à la parcelle irriguée

Abstract

This work revolves around the objectives of developing hydroponics and evaluating the efficiency of irrigation water use (WUE) at the level of seven (7) Great Irrigated Perimeters (GIP) located in North-Eastern Algeria: Bounamoussa, Safsaf, Guelma- Bouchegouf, Zit Emba, Jijel-Taher, K’Sar Sbahi et Sedrata. The perimeters are equipped with pressurized water distribution networks and their water supply is ensured by seven dam-reservoirs. These Great Irrigated Perimeters have benefited from several network rehabilitation actions. The analysis is based on the impacts of hydraulic improvements (Water Law 2005) on the efficiency of the use and the level of valuation of irrigation water, through indicators that measure both the overall efficiency of the networks (E1) and the plot efficiency irrigation (E2). The irrigation water use efficiency index (E1 *E2) allows tracking of efforts realized in an economy of water. This method is adopted within the framework of the Mediterranean Strategy for Sustainable Development (MSSD) of the Blue Plan (2012). Our study showed the significant potential in the north-eastern region of Algeria, but the waterclimatic contrasts between the north and the south affect the water soils balance. he need to store water to outeface irrigation demand. This shows the imperative to store water to cover irrigation demand. Between 2006 and 2016, the average annual volume allocated to the perimeters was around 100.92 hm3, three quarters of this volume being shared between the three main perimeters: GuelmaBouchegouf (37.24 hm3), Bounamoussa (31.82 hm3) and Safsaf (12.90 hm3). The theoretical quota for the volume of water allocated to irrigation varies significantly from year to year, depending on the climatic year and the volume of water stored in the dam. The perimeters have shown encouraging progress in terms of overall network efficiency (E1), the average yield at the scale of the irrigation networks of all the GIP studied is 71,5%, with an average of between 67.9 (Bounamoussa) and 93.5% (Zit Emba). At the regional level, for the 2016 campaign, the efficiency (EUE) over all of the seven large irrigated perimeters is around 59.5 %, varying between 40.8 % (Guelma Bouchegouf) and 80.7 % (Jijel -Taher). Despite the remarkable progress, this level of efficiency remains unsatisfactory, in particular for the three large perimeters which mobilize large volumes of water (Guelma- Bouchegouf, Bonmoussa and Safsaf), due to losses during transport, leaks and wastage during use At the local level, the perimeter irrigated of Guelma-Bouchegouf, the study of the 2016 irrigation campaign focused on the five irrigated sectors that form this perimeter. The average network efficiency (E1) is 57.9 % greatly affected by the loss of water during transport from the dam to the irrigation perimeter. Progress in installing more water-efficient equipment has improved plot efficiency (75%). Also, progress is recorded in the extension of irrigated areas. Progress has been made with regard to the extension of irrigated areas, and agricultural production is now oriented towards agricultural production sectors and better value for one cubic meter of irrigation water. However, the Great perimeters irrigate only 31% of the equipped surface, for reasons linked to internal and external factors of the agricultural water sector ; In addition, much efforts remains to be done for effective management of water demand.