摘要
The management of water resources requires an adequate understanding of the relationship between the various components of the hydrological cycle. The accelerated urbanization and agricultural development impose the concern about the sustainability of water resources, particularly in arid and semi-arid regions. In such environments, water scarcity and drought often lead to intensive groundwater abstraction which can adversely affect the hydrological system. Severe over-exploitation of groundwater has been observed on the Aleppo basin of the Al Qweek River. The Al Qweek valley constitutes the central part of the study area (southwestern parts of the Aleppo basin). The region is characterized by a semi-arid climate with an average annual precipitation of 325 mm. The intensive exploitation of the upper aquifer in the catchment is responsible for a continuous decline of the piezometric levels with an average of 1.8 m/year. The objective of this study was to investigate the relationship between the upper aquifer and the Al Qweek River within the catchment boundary using streamflow and hydrograph separation techniques by means of daily discharge data for both the Al Qweek and Al Qwaak rivers. HydroOffice was used for the base-flow separation, flow duration curves (FDC), and recession curve displacement analysis. Furthermore, groundwater recharge was estimated by means of RECESS and RORA. This is the first study using the hydrograph separation method in this region to our knowledge. The results indicate a proportional relationship between the surface and groundwater with an average discharge fluctuation that ranged from 0.30 to 0.20 m for the Al Qweek and Al Qwaak rivers, respectively. The results also revealed a dominant base flow in the catchment that ranged from 86.3 to 88.2 % of the total flow with a computed base-flow index that varied from 0.85 to 0.90 in all gauge stations, indicating a stable flow regime in the region. Furthermore, the high base flow is resulting in high permeability conditions of the upper aquifer and low direct surface runoff. The visual interpretation of the FDC suggests sustained base flow from groundwater storage. The low-flow index indicates an average contribution of groundwater storage of 45 to 58 %. The result of recession curve analysis shows a recession constant from 0.8 to 0.9 indicating a dominant interflow and low overland runoff. Furthermore, the results also show that estimation of groundwater recharge using RORA is inappropriate for the region of interest. Keywords Surface–groundwater Interaction Base-flow separation Recession curve analysis Net groundwater recharge