The morphology of the Oosterschelde
Daily, large transports of sediments take place
in the Oosterschelde, but the amount of
sediment transported by ebb and flood flows
are more or less counterbalanced. Nevertheless
during the last hundred years a continuous
erosion has been noticeable. Through research
in a bi-dimensional model efforts were made to
obtain more insight into the processes that play
a role here. In the fore-delta not only the
current, but also the wave action plays a role in
the morphological development. There are
certain general expectations with regard to the
influence of the storm-surge barrier in the
Oosterschelde on the morphological
development.
Evolution to date regarding the research into
the fresh water/salt water situation
The salinity in an estuary is neverthe same; it
varies in function of time and place. This holds
in particular for the Oosterschelde which is in
communication with both fresh water basins
and flows. The parts with the highest degree of
fresh water are the Krabbenkreek and the Kom.
The percentage of fresh water in the Ooster
schelde commensurates with the influx of fresh
water. The influx of salt water basically occurs
through the tidal flows. When the tidal
influence decreases then the degree of the
salinity will diminish accordingly. Differences in
density between fresh water and salt water will
hardly influence the mixing process, with the
exception, however, of the northeastern branch.
The present research is aimed in particular at
enhancing the accuracy of the prognoses for the
salt distribution in the future situation on the
Oosterschelde and the Zoommeer.
Partial heightening of dikes near the
agglomeration of Yerseke
The partial heightening of the dikes, which are
meant to give a temporary added protection
until the storm-surge barrier will be completed
in 1985, has caused various problems in certain
built-up areas. Among others, the alignment
through the agglomeration of Yerseke has
occasioned much brain-racking. The plans on
which the specifications will be based divides
the enlargement of the dikes into four phases,
which have been extensively described in this
paper.
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