LONG-TERM WATER DEMAND ASSESSMENT USING WEAP 21: CASE OF THE GUELMA REGION, MIDDLE SEYBOUSE (NORTHEAST ALGERIA)

: The Guelma sub-basin, an integral part of the Middle Seybouse basin, covers a surface area of 818 km 2 , subject to subhumid climate. The main surface water reservoir is the Bouhamdane dam with a regulated volume of 55 hm 3 . The main underground reservoirs are found in the aquifer systems of the Guelma plain, the Bouchegouf plain, the H’lia water table and the Heliopolis karst. To enable the rational use of water resources in the study region, integrated management of these resources remains essential. In this work we used WEAP 21 software (Water Evaluation and Planning), for the modeling of water resources, considering the year 2017 as the reference year for 2020-2050, with a base scenario «water demand”. The results of the simulation show a significant water shortage of around 50.5 hm 3 , marking a scarcity of the resource, noticed from the reference year 2017, because of the unfavorable climatic conditions which significantly impacted the water reserve in the municipalities of the watershed. This shortage will decrease to a volume of 31 hm 3 in 2024, and 104.20 hm 3 in 2050.