Estimating Aquifer Hydraulic Parameters Using Electrical Resistivity Tomography in Recent Sediments of the Bazian Sub-Basin, Kurdistan Region, Iraq.

Groundwater is the principal source of drinking water, domestic use, livestock, and agricultural irrigation in the Bazian region. Estimating aquifer hydraulic parameters and demarcating aquifer potential zones in the Bazian sub-basin are the primary goals of this research. Combining two-dimensional electrical resistivity tomography (2D ERT) and pumping tests gives a more efficient and cost-effective way to estimate hydraulic parameters, including transmissivity (T) and hydraulic conductivity (K), as well as Dar-Zarrouk parameters, including transverse resistance (Tr) and longitudinal conductance (S). Eight two-dimensional electrical resistivity tomography profiles were carried out at different sites to determine groundwater potential zones, and five pumping tests were conducted close to ERT profiles to estimate the aquifer characteristics. The 2D ERT data revealed the presence of two types of aquifer zones. The upper zone, which is composed of the Recent Sediments, is considered a high-potential groundwater zone. In contrast, the lower zone exhibited low resistivity values, indicating the presence of a poorly aquifer zone in the Kolosh Formation. Two relationships between the Dar-Zarrouk parameters from ERT and the hydraulic parameters from pumping tests were established to evaluate the properties of the Recent Sediments at sites lacking pumping test data. The findings suggest that the T values range from 33.4 to 150.9 m2/day, whereas the K values range from 0.7 to 1.3 m/day across the entire research area. Additionally, porosity (ϕ) and aquifer thickness (h) were assessed, yielding values of 13.4–19.6% and 40–115 m, respectively.Keywords: Groundwater, ERT, Dar-Zarrouk, Aquifer properties, Bazian.