ere. Twice a day prognoses will be made,
ased on data about the swell, the
ave-pattern, the current, the wind and the
/orking conditions in the mouth, but also at the
rear of the Oosterschelde. The Centre will be
anned by a staff from Rijkswaterstaat and the
N.M.I. (Royal Netherlands Meteorological
I 'stitute).
asearch into the wave direction across the
i outh of the Oosterschelde
direction spectrum of waves can be drawn,
i e. a graphic illustration of the energy a wave
c omprises in different directions and at various
equencies. For the storm surge barrier and its
construction it is important that the wave
rection spectra are broadly known.
V ,'ith the aid of aerial photography, local visual
oservation and modelcalculations one tries to
ain insight into this matter. Lately the
ssistance of radar and laser technics have been
>ked for too. On the former REM-island at
oordwijk a gauge has also been installed for
ontact measurements.
ie design of the Oesterdam
o preserve the greatest possible part of the
osterschelde as a nature and shellfish area the
gnment of the Oesterdam will run as far
istward as possible. The height of the crest
id the cross section of the dam have been
imarily based on the water restraining
nction of the dam. The dam will have other
nctions tod however. On it two seperate roads
ave been planned, one for fast and one for
ow moving traffic. Furthermore simple
creational provisions will be made. The
aometrical pattern of both roads, which
imetimes run over the crest and sometimes
cer the banks, promises to be pleasantly varied.
and reclamation for the compartment works
a to now no provisions have been made in the
anning for the supply of approx. 13 million m3
sand needed for the compartment works,
ne location where sand can be reclaimed lies
the Krammer. From this area sand will be
edged forthe closure of the Philipsdam. Six
her places where sand can be reclaimed
ve been spotted on both sides of the
3sterdam in the vicinity of Bergen op Zoom.
I locations will be closely examined on the
Mowing aspects: the ecological responses to
nd reclamation, the operational problems
at may occur, what are the costs per unit and
what places can the reclaimed sand be used.
A memorandum has been drafted and its
contents discussed with the parties interested.
Geomorphologic changes occurring in the
Grevelingenmeer
When the Grevelingen-basin was closed off
from the sea and the tide disappeared, it turned
into a stagnant salt water lake. Consequently
the geomorphology of the area was greatly
affected. In this contribution the alterations that
have occurred in the landscape since 1971 are
discussed per item. These are: the mud-flats,
shoals, vegetated mud flats, shores and shallow
parts of the water which are influenced by
waves, wind, the water flowing down, the
ripening of the bottom and the vegetation.
Special attention is given to the impact of
human action on all these processes.
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