Hydro-ecological relations in the Delta Waters

In this paper (Section 2) first the historic evolution of the tidal
landscape is analysed, resultbg in some 'hypotheses' M general
response mecbnism to chaqges in the natural driving forces. !hen
(Section S) the major changes of the tidal landscape in the respective
basins of the Dutch Delta area over the last decadee are broadly
reviewed. The observed phenomena are confronted with the general
'hypotheses' of Section 2 and discussed in relation to the specific
shift in natural driviog forces. Flnatly a short outlook on future
developments is given.
2 EVOLUTION OF THE TIDAL LANDSGAEE DURmG RISTORiC TINES
2.1 Kelinium and Oosterschalde
During Roman times the coastline of the South-Vest Netherlands only
showed two main tidal inlets (Fig. 1).
At that time the northernmost inlet, known in Roman writings as
Aelinium, was the main distributary of the rivers Rhine and Ueuse, and
partly of the river Scheldt (Zagwljn. 1987). During the next centuries
the importance & this estuary continually diminished, in favout of the
development cf the sarly Haringvliet, GreveBgen and Onsterschelde
estuaries.
Figure 1 The South-West Netherlasds 2000 B.P.
circa 1550
(Zagwiju. 1987) and