Morphology of estuarine bedforms, Weser Estuary, Germany

Large bedforms (dunes) are present in many shallow-water environments. Knowledge of their dimensions and dynamics is required for river coastal management. In tidal rivers estuaries, the interaction among hydrodynamics (which results from action flows), sediment transport bedform shape size complex. study, distribution morphology Weser Estuary, Germany, were investigated. Bedforms identified bathymetric data monthly multibeam echosounder surveys along navigation channel during years 2009 to 2013. Their characterized. most channel, except at position estuarine turbidity maximum where dredging carried out. Average length varied between 20 60 m height 0.3 1.6 m. Bedform asymmetry spatially temporally estuary. times high discharge, generally more ebb-asymmetric than low discharge. The predominantly two-dimensional low-angle dunes with steepest slope situated near crest. A significant proportion possessed a steep face (portion lee side steeper 15°). This implies that they likely create flow separation turbulent wake, strong potential induce roughness. However, important variations area density noted, both estuary as function phase (ebb or flood) seasonal variation have wide implications terms understanding modelling estuaries.