ASSESSMENT OF THE INFLUENCE OF THE DJORF TORBA DAM ON THE TURONIAN AQUIFER SYSTEM IN BÉCHAR (SOUTHWESTERN ALGERIA)
Mekkaoui Abderrahmane1, Ameri Sarra2, Lachache Salih2, Bekhira Abdelghani3, Belkendil Abdeldjalil4
1Laboratory FIMAS, Department of Civil and Hydraulic Engineering, Tahri Mohamed University, Béchar Algeria
2Technology Institute, Nour Bachir University Center, El-Bayadh, Algeria
3Department of Civil and Hydraulic Engineering, Tahri Mohamed University, Béchar, Algeria
4Land Use Planning Research Center (CRAT), Zouaghi Slimane Campus, Ain El Bey Road, 25000 Constantine, Algeria
Abstract: This study assesses the influence of the Djorf Torba Dam on the Turonian aquifer system in the Béchar region, southwestern Algeria, focusing on reservoir water infiltration into the underlying Turonian and Quaternary aquifers hosted in fractured limestone formations. Infiltration processes are controlled by aquifer hydrodynamic properties, reservoir water levels, and surface area.Monitoring data from external piezometers show that 72.2% of the instruments screened in the Turonian aquifer exhibit groundwater level variations closely correlated with reservoir water levels, with correlation coefficients ranging from 0.75 to 0.94. Piezometric mapping indicates groundwater levels between 693 m and 697.67 m, forming two recharge domes connected to the main branches of the reservoir. When reservoir levels exceed 695 m, infiltration significantly increases along major Turonian fault zones. Water balance calculations estimate an average infiltrated volume of 22.57 hm³/year, including 17.56 hm³/year recharging the Turonian aquifer and 5.02 hm³/year contributing to the Quaternary groundwater. Hydrochemical analyses reveal that groundwater chemistry reflects reservoir water composition, with higher solute concentrations resulting from leaching processes. These findings highlight the strong hydraulic and geochemical impact of the Djorf Torba Dam on the Turonian aquifer system.
Keywords: Djorf Torba Dam; Turonian aquifer; reservoir infiltration; groundwater–surface water interaction;
VOLUME 10 ISSUE 01 2026: 210 – 218