Bed form-induced hyporheic exchange and geochemical hotspots

113: Hyporheic Exchange Flows

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 docu...

Impact of Heterogeneity, Bed Forms, and Stream Curvature on Subchannel Hyporheic Exchange

Hyporheic exchange in gravel bed rivers with pool-riffle morphology: Laboratory experiments and three-dimensional modeling

[1] We report the first laboratory simulations of hyporheic exchange in gravel pool-riffle channels, which are characterized by coarse sediment, steep slopes, and three-dimensional bed forms that strongly influence surface flow. These channels are particularly important habitat for salmonids, many of which are currently at risk worldwide and which incubate their offspring within the hyporheic z...

Modelling hyporheic exchange: From the boundary layer to the basin

Hydrological connections in streams occur longitudinally along the stream channel, laterally with the floodplain and vertically with the hyporheic zone. These connections are an important control on freshwater ecosystem processes at the basin-scale including nutrient cycling and retention; movements of organisms to complete life stages; and the provision of refugia during high and low flow peri...

How does subsurface characterization affect simulations of hyporheic exchange?

We investigated the role of increasingly well-constrained geologic structures in the subsurface (i.e., subsurface architecture) in predicting streambed flux and hyporheic residence time distribution (RTD) for a headwater stream. Five subsurface realizations with increasingly resolved lithological boundaries were simulated in which model geometries were based on increasing information about flow...