Evaluation of MIKE SHE and MIKE 11 Models for Simulating the Hydrology of Surface Water and Groundwater in the Foumanat Plain Aquifer

Shallow alluvial aquifers in watersheds with multiple rivers experience complex hydrological and hydraulic interactions among different subsystems, such as the aerated zone, groundwater, and surface water. In such aquifers, combining hydrological models of surface water and groundwater is crucial for accurately simulating and describing these processes. This study focused on developing and evaluating the MIKE SHE integrated hydrological model and the MIKE 11 hydrodynamic model to simulate hydrological and hydraulic processes in the Foumanat aquifer. To establish a dependable model, groundwater levels and river flow were concurrently calibrated at the control points of observation wells and hydrometric stations within the study area. Calibration was performed based on sensitivity analysis, utilizing parameters such as saturated hydraulic conductivity, leakage coefficients, and Manning's roughness coefficient. Despite the natural heterogeneity of the region, the model demonstrated satisfactory performance, yielding an absolute error of less than one for groundwater level estimation and less than 0.5 for flow rate estimation at the hydrometric stations. During the wet season (October to March), the combined evaporation and transpiration (ETa) amounts to 0.4 times the total rainfall. In contrast, during the dry season (April to September), the combined evaporation and transpiration (ETa) equates to 7.3 times the total rainfall, emerging as the main contributor to water loss. These findings apply to a dry year, implying that these ratios would increase in dry and average years.