Keywords:
mainland barrier dunes
tidal inlet
dune stability
Contact: Staatsbosbeheer regio Noord Holland, POBox
62, NL-1800 AB, Alkmaar
Location: NL, North Holland, dune area between Bergen
and Schoorl
Management
The Holland coast is a rigid line of dunes planted with marram
grass to stabilize and protect the coast. The new approach for
coastal protection is dynamic coastal management. Main goal is
to develop and conserve nature values and to protect the hinterland
from flooding. Stabilisation prevents the coast from developing.
The sand dune area between Bergen and Schoorl has some low
lying valleys behind the shoreline.One of these valleys is the
Parnassiavallei. This valley was most suitable for the creation
of a tidal inlet for example because of a second ridge of high
dunes behind the foredunes, wich are able to protect the hinterland
from flooding.
Tidal inlet
In 1997 a tidal inlet is created. The valley is excavated
to 1,5 m above sea-level. It has a minimum width of 50 meters
and a maximum width of 300 metres to let the sea and the drifting
sand enter the valley. The sea enters the inlet 5 to 10
times a year. The topsoil of the valley is removed to allow
the fresh water back to the surface and to allow wind to
blow the sand away. The release of the groundwater will create
a moist dune valley.
Results
In one year sand drift has increased significantly. Because of
drifting sand, bringing in calcareous sand from the shoreline,
the soilproperties in the valley have changed and vegetation that
is typical for dynamic dunes, reappeared. It is expected that
in the future more rare species will return, and the valley will
be a habitat for birds, sand lizards and other living creatures.
So far, there have not yet been many breeding birds in the valley,
but from 1999 on the southern part is closed for the public, so
it is expected that in the future breeding birds will appear.
The dunes of Schoorl
References:
- Dutch commissioners summon the sea out into the dunes, C.
de Feijter, Coastline 1997-2
- Hees, I.E.M van & M.P.J.M. Janssen, Dynamiek in de kustzone,
een advies voor het herstel van dynamische processen in de kustzone
van de Schoorlse duinen, Stichting Duinbehoud, Leiden, 1995.
(EUCC Library code 33Nbd 95)
- De kerf bij Schoorl, geomorfologie en kalkgehalten situatie
1998, S.M.Arens, R.M.K.Haring, rapportnummer RAP98.03, opdrachtgever
Rijkswaterstaat. (EUCC library code 33 Nbd98)
- The North Holland dune reserve, Coastline special, Coastline
1992 1/2, 17-32, coproduction between PWN waterleidingbedrijf
and the EUCC, Leiden, 1992 (EUCC Library code 33Nbd92)
- internet : www.staatsbosbeheer.nl
