SEDIMENTATION PROCESSES IN TIDAL CHANNELS AND TIDAL BASINS CAUSED BY ARTIFICIAL CONSTRUCTIONS

[摘要] Tidal basins and tidal rivers especially in areas of agricultural and industrial interest are more and more regulated and improved for different reasons such as draining, disposal of waste water, shipping and storm flood protection. This is - up to now - mainly done by dams, dikes, training walls, channel dredging, storm surge control barriers, etc .. In general, the tidal motion (tidal range and tidal velocities) in the whole system is affected by these man-made changes in the cross-sectional area of the tidal river. The hydrographical effects caused by such artificial constructions in tidal rivers have been outlined in the papers of H.G. WITTMER and al.(12). However, the morphological consequences of such measures are largely unknown. The analysis of a real system, such as the EIDER-Estuary at the German Bay, which was affected by both a reduction in its tidal prism by the construction of a tidal dam in 1936, and by a reduction of its cross-sectional area by a storm surge control barrier in 19 72, must therefore be highly appreciated. In general, the most important changes of a tidal regime are caused by two different types of artificial influences: - horizontal reductions of the tidal volume (for instance by damming-off a tidal river) - vertical reductions of the cross-section(s) at any particular part of the tidal regime (for instance by storm surge control barriers or training walls) In both cases the existing equilibrium conditions are disturbed and the relationships between the horizontal and vertical components of the tidal motion are distorted more or less according to the distance from the structure.

[学科分类] 建筑学

[关键词] sedimentation;tidal channel;tidal basin