4.4 The marine clay landscape
4.4 The marine clay landscape
After studying this section, you will be able to:
Explain how the lower parts of the Netherlands have been formed during the Holocene
Recognise the regions in the marine clay landscape and their features
What are myths (which is not true) about water and the Netherlands?
The NL has regions enclosed by dyke rings
We will always keep our feet dry because of expertise
Half of the Netherlands is below sea level
Our coastline has been shortened
Different polders
sea polder = zeepolder
peat polder = veenpolder
reclamed lakefloor = droogmakerij
IJsselmeerpolders = Example: Noordoostpolder (Flevoland)
When the sea is calm, clay or sand are being deposited
📌 Seapolder:
Dykes around the new land
About sea level
Sand and clay was brought by the sea
Waddengebied plus Zeeland (North sea)
peat polder (Ch4.5)
reclaimed lakefloors
Reclaimed lake floor
It is a polder.
How was it made?
First a ring dyke was built
Then the channel around it was dug
Then it was pumped dry and the water was transported away
Back in the day
Now
By sedimentation we get extra land along the coast. What type of polder is it?
sea polder
peat polder
reclamed lakefloor
IJsselmeerpolder
Where do we have most peat polders?
In the east of the NL
In the south of the NL
In the west of the NL
In the north of the NL
Why did we build the IJsselmeerpolders?
to protect us against flooding
to have more land for agriculture
to build a second airport
to travel faster from Randstad to the north
Dune area between Den Haag / Wassenaar / Noordzee
Is there any space for sea water, dunes etc in a densely populated area?
3 ways to protect us better from the sea in the future:
to avoid more coastal erosion: beach nourishment (zandsuppletie)
give more space to the dunes: dynamic coastal management
tidal landscape supplies extra sediment
Beach nourishment
Dynamic coastal management
Protect the coast line by reinforcing dykes and extra sand:
Which uses has the zandmotor?
Homework
First 5 assingments of 4.4
Map
THE END
Essence
During the Holocene, layers of sand and clay were deposited in the lower parts of the Netherlands. In the northern marine clay landscape, you can still find many mounds. Kwelders were reclaimed by building dykes and used for agriculture. In Noord- Holland, Zuid-Holland and Flevoland, polders can be found. In some of these, a great deal of human activity takes place. Marine clay is a good soil type for agriculture.