The Rhine, the Meuse and the tributaries of these rivers have had many catchment areas.
These rivers have deposited a thick layer of sand and river gravel over the whole of the Netherlands.
Terms:
tributaries = zijrivieren
catchment = stroomgebied
Slide 2 - Slide
Sand and river gravel in the Netherlands
Why is it that thick layers of sand and river gravel were deposited all over the Netherlands by these rivers?
The Netherlands lies in the lower course of the catchment area of the Rhine and the Meuse. Here the water flows slowly and the material carried by the rivers is deposited.
Slide 3 - Slide
Learning objectives
You can describe some measures that the people in the Dutch landscape below sea level have taken to protect themselves against the water.
You can describe how layers of peat have formed in the Dutch landscape below sea level.
You can tell from a photo or a map whether a landscape is located above or below sea level.
Slide 4 - Slide
Slide 5 - Slide
Formation of peat
In the Netherlands below sea level, new soil types were deposited during the period of the rising sea level.
The beaches and dunes were formed by the sea.
Behind the dunes was a marshland, here a layer of peat was formed.
Slide 6 - Slide
Formation of peat
About 1000 years B.C. a new beach ridge formed along the coast.
Behind the beach ridge tidal flats were formed. In these tidal flats the water often stood still and clay was deposited.
When openings appeared in the dunes, the sea water came behind the dunes again and a layer of peat was formed.
Slide 7 - Slide
Slide 8 - Slide
Slide 9 - Slide
Slide 10 - Slide
Slide 11 - Slide
Terps and dykes
Where is the dyke on the map?
Slide 12 - Slide
Sedimentation
Which area in the photo (A or B) lies higher compared with the sea level?
Slide 13 - Slide
Sedimentation
Which area in the photo (A or B) lies higher compared with the sea level?
It is B. In area B the sedimentation of sand and clay at high water continues, while area A lies behind the dyke.
Slide 14 - Slide
Protected or unprotected?
Which letter(s) on the topographic map lie(s) outside the dyke?
Slide 15 - Slide
Protected or unprotected?
Which letter(s) on the topographic map lie(s) outside the dyke?
Letter A lies outside the dyke. Here you find tidal flats.
Area B is a polder. What sort of water has to be pumped out of B? How do they do this nowadays?
Slide 16 - Slide
Protected or unprotected?
Area B is a polder. What sort of water has to be pumped out of B?
How do they do this nowadays?
Rainwater is pumped away using pumping stations. In the olden days windmills were used.
Slide 17 - Slide
Dutch polders
Een zeepolder ligt aan zee en ontstaat door sedimentatie van zand en klei. De zee zet door haar eb- en vloedbewegingen zeeklei af tegen de zeedijk. Wanneer een nieuw buitendijks stuk land groot en hoog genoeg was, legde men er een dijk omheen. Vervolgens pompte men de polder droog.
Een droogmakerij is een polder. Hoe werd deze polder gemaakt?
Eerst werd er een ringdijk gebouwd.
Daarna werd er een ringvaart gemaakt.
Tenslotte werd de polder doorgepompt door bijvoorbeeld een molen.
Veenpolders komen vooral voor in het westen van Nederland. Door grootschalige turfwinning (turf = gedroogd veen) ontstonden vanaf de middeleeuwen enorme plassengebieden die in een later stadium weer werden drooggelegd door middel van inpoldering.
Slide 18 - Slide
Learning objectives
You can describe some measures that the people in the Dutch landscape below sea level have taken to protect themselves against the water.
You can describe how layers of peat have formed in the Dutch landscape below sea level.
You can tell from a photo or a map whether a landscape is located above or below sea level.
Lesson duration is: 60 min
