Application of a Composite Model to Estimate Baseflow, Effective Recharge, and Hydraulic Conductivity

This study employs a composite baseflow model to estimate baseflow, effective recharge, and hydraulic conductivity. Baseflow recession analysis is a hydrological method used to analyze the gradual decline of streamflow during dry periods when groundwater serves as the primary source of water for rivers and streams. Previous approaches often rely on either linear or nonlinear Boussinesq equations, both of which have limitations. The linear Boussinesq equation fails to capture the nonlinear behavior of baseflow, while the nonlinear equation struggles to represent low discharge values, where baseflow recession is most occurred. Furthermore, the nonlinear model introduces assumptions and overlooks baseflow contributions from below the stream’s water level. To address these issues, this study applies the composite model for baseflow estimation. The composite model effectively separates the baseflow component of stream discharge. Following this, effective recharge and hydraulic conductivity are estimated using a high-resolution MODFLOW model, providing more accurate and comprehensive insights into groundwater-surface water interactions.