Water having entered a stream channel from the surrounding catchment may continue to have connections with the catchment. In the stream's hyporheic zone, water “in the channel” exchanges with “groundwater” in the bed of the stream. Hyporheic exchange flows typically occur at scales small relative to the length and volumetric transport characteristics of the stream. Nevertheless, it is well documented that hyporheic exchange flows significantly influence nutrient dynamics. Additionally, there is evidence of hyporheic exchange flows similarly influencing the processes establishing the concentrations of major-ions and metals in stream-catchment systems. It is within the contexts of (i) solute transport and (ii) the continuing connections [...]
