Change to hydrodynamics (TraC)

Changes to hydrodynamics are typically large-scale responses to large-scale modification of the existing coastal, transitional or fluvial system though they may occur at a variety of spatial (wave oscillation to wave field) and temporal scales (seconds to decades). Changes to hydrodynamics may manifest as increase or decrease to wave height, length or duration, increases or decreases to tidal flow and associated current vector speed, duration and orientation, the duraction of the flood and / or ebb tide, changes to speed of tidal propagation and upstream changes to the saline limit and fluvial discharge variations.

The hydrodynamics of a coastal zone or estuary are dependent on a range of factors, including water body geometry (surface area, bathymetry and water depth), accomodation space and the nature of the prevailing external atmospheric forcing parameters relative to tidal state (e.g. spring and neap tides). Major modifications to the coastal and transitional system (e.g. large coastal flood and erosion protection schemes) can cause considerable changes to the way in which water moves within and between different parts of the system, and can therefore have a considerable impact on the geomorphology of coastal and transitional waters.

The following engineering activities are likely to cause changes in tidal dynamics: