Effects of Heterogeneous Stream‐Groundwater Exchange on the Source Composition of Stream Discharge and Solute Load

The exchange of water and solutes between the stream groundwater along a network affects source composition discharge solute load in stream. To date, this hydrologic turnover has only been analyzed with respect to water. In study, we extend concept analyze effects different conditions on spatial patterns magnitude fluxes. Based coupled stream-groundwater model built MODFLOW using Streamflow-routing package, simulated 30 km length evaluated evolution under precipitation streamflow conditions. Results show that even for highly variable conditions, direction (loss/gain) remained unchanged consistently gaining or losing reaches, but changed interspersed transitional reaches. comparison nitrate revealed decoupling contribution from stream, as zones high gains do not necessarily coincide concentrations. Overall, nearly 80% total contributions outflow catchment were generated over 20% length. Our research highlights importance distinguishing streams. This turn implies reduce groundwater-borne nutrient loads streams, measures need focus specific reaches highest contributions.