Hyporheic Exchange in Mountain Rivers I: Mechanics and Environmental Effects

Abstract

Hyporheic exchange is the mixing of surface and shallow subsurface water through porous sediment surrounding a river and is driven by spatial and temporal variations in channel characteristics (streambed pressure, bed mobility, alluvial volume and hydraulic conductivity). The significance of hyporheic exchange in linking fluvial geomorphology, groundwater, and riverine habitat for aquatic and terrestrial organisms has emerged in recent decades as an important component of conserving, managing, and restoring riverine ecosystems. Here, we review the causes and environmental effects of hyporheic exchange, and provide a simple mathematical framework for examining the mechanics of exchange. A companion paper explores the potential effects of channel morphology on exchange processes and the hyporheic environments that may result in mountain basins (Buffington and Tonina 2009).

Fine sediment deposition and interstitial flow effects on macroinvertebrate community composition within riffle heads and tails

“…A reduction of channel depth typically forces water into the sediments at the heads of riffles resulting in downwelling water. The water passes through the interstitial spaces of the sediments (vertically and horizontally) in a downstream direction, until at the tail of the riffle, increasing water depth produces a zone of low pressure forcing water out of the sediments and into the open channel (Tonina & Buffington, 2009;Hassan et al, 2015). However, flow paths are often complex and interstitial flow may vary as a function of river stage, especially high flow events (Käser et al, 2009;Dudley-Southern & Binley, 2015).…”

The role of organisms in hyporheic processes: gaps in current knowledge, needs for future research and applications

“…Mermillod-Blondin et al, 2000;Nogaro et al, 2006Navel et al, 2010) or at the riffle-pool scale (Schmid and Schmid-Araya, 2010), but research is still required for upscaling these microcosm observations to reach, floodplain, and catchment scales. Boulton et al (1998) focused on the micro-habitat (mm to mm), the riffle-pool successions (m to dm) and the catchment scales (100-1000 km); but we know very little about intermediate scales (reach, river section, or floodplain scales, 1-10 km; Creuze´des Chaˆtelliers and Reygrobellet, 1990;Tockner et al, 2002) where valley shape, depth of the substratum, and lateral aquifer levels seems to be determinant parameters for hyporheic hydrology (Woessner, 2000;Malard et al, 2003;Weng et al, 2003;Poole et al, 2004;Buffington and Tonina, 2009;Tonina and Buffington, 2009). The combination of large-scale studies ) and hydrological modeling (Peyrard et al, 2008) may be an efficient strategy to understand the interactions between physical characteristics and biological processes at these multiple scales, even if processes that take place deep in the groundwater (i.e.…”

Spatial patterns of hyporheic exchange and biogeochemical cycling around cross‐vane restoration structures: Implications for stream restoration design

“…Channel bed morphologies, such as steps, pools, and riffles, intensify the vertical flux of water through the hyporheic zone by a variety of hydraulic mechanisms [Elliott and Brooks, 1997;Hester and Doyle, 2008;Buffington and Tonina, 2009;Tonina and Buffington, 2009;Endreny et al, 2011a]. Flow paths that redirect stream water through the hyporheic zone introduce dissolved oxygen (DO), organic material, and nutrients to the streambed and increase the time that these solutes are in contact with sediments and organisms [Findlay, 1995;Brunke and Gonser, 1997;Boulton et al, 1998].…”