Currents and water levels in the estuary of the river Elbe are determined by the tidal influence of the North Sea, the discharge from the Elbe catchment area as well as the wind in the area. The tide of the North Sea has a period of approx. 12.5 hours. Entering the Elbe estuary the form of the tidal wave is changed by friction and reflexion. The duration of high tide decreases whereas the duration of low tide increases, leading to large flood and small ebb velocities.
The tidal cycle in the Lower Elbe was recorded from the Leading Light Hamburg-Blankenese in July 2011 and is shown in fast motion in two different velocities. The falling and rising water level, the transition from ebb to flood flow as well as flow conditions at the groyne heads and in the groyne fields can be observed. The video recording was kindly supported by the Hamburg Port Authority.