Sedimentation and flow patterns induced by regular and modified groynes on the River Elbe, Germany

Abstract

Groynes help to protect river banks and support water levels for navigation. Since recently, groyne fields are considered as surrogate habitat for various species and may, in terms of ecology, partially replace flood plains that were lost in the course of river training in the last centuries. In order to maintain and improve the hydraulic function and ecological value of groyne fields, the German Federal Institutes of Hydrology and the Waterways Engineering and Research studied innovative groyne types and regular groynes on the River Elbe, Germany. In a 10-year field campaign, groyne field hydraulics and morphology were monitored using acoustic Doppler current profiler and echo-sounding techniques. The data is used to assess groyne field heterogeneity and morphodynamics over the 10-year period as well as flow patterns at different flow stages. The results indicate a high morphological activity in the groyne fields associated with flood discharges. Significant sedimentation in the bank regions was observed, whereas sedimentation in deeper areas of the groyne fields was less pronounced. The sedimentation patterns and rates in the groyne fields are, to some extent, found to be influenced by different groyne types and associated flow patterns.

Juvenile coho salmon track a seasonally shifting thermal mosaic across a river floodplain

“…reduced niche diversity) due to loss of landscape complexity and ecological integrity is diagnostic of human‐dominated landscapes worldwide (Peipoch et al ., ). Hydrologic alteration (Kingsford, ; Poff et al ., ) and shoreline armouring (McCartney et al ., ; Henning & Hentschel, ) directly suppress the mechanisms that generate and maintain active floodplains that provide growth opportunities to mobile organisms.…”

Transport of suspended sediments under the influence of bank macro‐roughness

“…(); Ten Brinke et al. (); Yossef and de Vriend (); Henning and Hentschel (). Recently, Sanjou and Nezu () analysed, for a constant planar configuration of rectangular embayments, the effect of bed slope on the mass and the momentum exchange between inner and outer flows.…”

“…Meile et al (2011a) and Sukhodolov (2014) analysed the effect of macro-roughness elements positioned in the channel bank in the flow resistance. The role of sediment siltation in groyne fields for the sediment budget of rivers was investigated by Abad et al (2008); Ten Brinke et al (2004); Yossef and de Vriend (2010); Henning and Hentschel (2013). Recently, Sanjou and Nezu (2013) analysed, for a constant planar configuration of rectangular embayments, the effect of bed slope on the mass and the momentum exchange between inner and outer flows.…”

“…Nevertheless, laboratory experiments relating the hydrodynamics and morphodynamics of lateral embayments are scarce and difficult to carry out (Henning and Hentschel, ), since sedimentation processes are related to the variability of discharge (or flow aspect ratio), geometrical configuration of the river banks and the sediment concentration transported in the flow. Thus far, only a few details about measured sedimentation in laboratory channels under such conditions can be found (Sukhodolov et al.…”

Ecohydraulics: linkages between hydraulics, morphodynamics and ecological processes in rivers

“…Other human interventions, such as groynes that protect riverbanks and improve navigation, only have an effect in the immediate vicinity of the structure. In the present special issue, Henning and Hentschel (this issue) and Jamieson et al . (this issue) optimized the design of groynes to improve their ecological value and hydraulic function.…”