The Info List - Polder

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A polder (Dutch pronunciation: [ˈpɔldər] ( listen)) is a low-lying tract of land enclosed by dikes that forms an artificial hydrological entity, meaning it has no connection with outside water other than through manually operated devices. There are three types of polder:

Land reclaimed from a body of water, such as a lake or the sea bed Flood plains separated from the sea or river by a dike Marshes
separated from the surrounding water by a dike and subsequently drained; these are also known as koogs especially in Germany

The ground level in drained marshes subsides over time. All polders will eventually be below the surrounding water level some or all of the time. Water enters the low-lying polder through infiltration and water pressure of ground water, or rainfall, or transport of water by rivers and canals. This usually means that the polder has an excess of water, which is pumped out or drained by opening sluices at low tide. Care must be taken not to set the internal water level too low. Polder land made up of peat (former marshland) will sink in relation to its previous level, because of peat decomposing when exposed to oxygen from the air. Polders are at risk from flooding at all times, and care must be taken to protect the surrounding dikes. Dikes are typically built with locally available materials, and each material has its own risks: sand is prone to collapse owing to saturation by water; dry peat is lighter than water and potentially unable to retain water in very dry seasons. Some animals dig tunnels in the barrier, allowing water to infiltrate the structure; the muskrat is known for this activity and hunted in certain European countries because of it. Polders are most commonly, though not exclusively, found in river deltas, former fenlands and coastal areas. Flooding of polders has also been used as a military tactic in the past. One example is the flooding of the polders along the Yser
river during World War I. Opening the sluices at high tide and closing them at low tide turned the polders into an inaccessible swamp, which allowed the Allied armies to stop the German army.


1 Etymology 2 Polders and the Netherlands 3 Examples of polders

3.1 Bangladesh 3.2 Belgium 3.3 Canada 3.4 Finland 3.5 France 3.6 Germany 3.7 Guyana 3.8 India 3.9 Ireland 3.10 Italy 3.11 Lithuania 3.12 Netherlands 3.13 Poland 3.14 Slovenia 3.15 South Korea 3.16 United Kingdom 3.17 United States

4 See also 5 References 6 External links

Etymology[edit] From Dutch polder ("polder"), from Middle Dutch polre, from Old Dutch polra, ultimately from pol- "part of land, elevated above its surroundings"; with augmentative suffix -er and epenthetical -d-. Polders and the Netherlands[edit]

Pumping station in Zoetermeer, Netherlands. The polder lies lower than the surrounding water on the other side of the dike. The Archimedes' screws are clearly visible.

The Netherlands
is frequently associated with polders, as its engineers became noted for developing techniques to drain wetlands and make them usable for agriculture and other development. This is illustrated by the saying: "God created the world, but the Dutch created the Netherlands[1]". The Dutch have a long history of reclamation of marshes and fenland, resulting in some 3,000 polders[2] nationwide. By 1961 6,800 square miles (18,000 km2), about half of the country's land, was reclaimed from the sea.[3] About half the total surface area of polders in north-west Europe is in the Netherlands. The first embankments in Europe were constructed in Roman times. The first polders were constructed in the 11th century. As a result of flooding disasters, water boards called waterschap (when situated more inland) or hoogheemraadschap (near the sea, mainly used in the Holland
region)[4] were set up to maintain the integrity of the water defences around polders, maintain the waterways inside a polder, and control the various water levels inside and outside the polder. Water boards hold separate elections, levy taxes, and function independently from other government bodies. Their function is basically unchanged even today. As such they are the oldest democratic institution in the country. The necessary cooperation among all ranks to maintain polder integrity gave its name to the Dutch version of third way politics—the Polder
Model. The 1953 flood disaster prompted a new approach to the design of dikes and other water-retaining structures, based on an acceptable probability of overflowing. Risk is defined as the product of probability and consequences. The potential damage in lives, property and rebuilding costs is compared to the potential cost of water defences. From these calculations follows an acceptable flood risk from the sea at one in 4,000–10,000 years, while it is one in 100–2,500 years for a river flood. The particular established policy guides the Dutch government to improve flood defences as new data on threat levels becomes available. Some famous Dutch polders and the year they were laid dry are:

(1609-1612) Schermer
(1633-1635) Haarlemmermeerpolder
(1852) As part of the Zuiderzee Works:

(1930) Noordoostpolder
(1942) Flevopolder

Examples of polders[edit] Bangladesh[edit] Bangladesh has 123 polders, of which 49 are sea-facing. These were constructed in the 1960s to protect the coast from tidal flooding and reduce salinity incursion.[5] They reduce long-term flooding and waterlogging following storm surges from tropical cyclones. They are also cultivated for agriculture.[6] Belgium[edit]

De Moeren, near Veurne
in West Flanders Polders along the Yser
rive between Nieuwpoort and Diksmuide Polders of Muisbroek and Ettenhoven, in Ekeren
and Hoevenen Polder
of Stabroek, in Stabroek Kabeljauwpolder, in Zandvliet Scheldepolders on the left bank of the Scheldt Uitkerkse polders, near Blankenberge in West Flanders Prosperpolder, near Doel, Antwerp and Kieldrecht.


Marsh Pitt Polder
Ecological Reserve Grand Pré, Nova Scotia


Söderfjärden Munsmo Two polders (totally 3 km2) near Vassor in Korsholm


Marais Poitevin Les Moëres, adjacent to the Flemish polder De Moeren in Belgium.

Germany[edit] Main article: Koog In Germany, land reclaimed by dyking is called a koog. The German Deichgraf system was similar to the Dutch and is widely known from Theodor Storm's novella The Rider on the White Horse.

Altes Land near Hamburg Blockland & Hollerland near Bremen Nordstrand, Germany Bormerkoog and Meggerkoog near Friedrichstadt 36 koogs in the district of Nordfriesland 12 koogs in the district of Dithmarschen


In southern Germany, the term polder is used for retention basins recreated by opening dikes during river floodplain restoration, a meaning somewhat opposite to that in coastal context. Guyana[edit]

Black Bush Polder, Corentyne, Berbice.


Region, Kerala[7][8]


Lough Swilly, Co. Donegal. Near Inch Island
Inch Island
and Newtowncunningham.[9]


Delta of the river Po, such as Bonifica Valle del Mezzano


Rusnė Island


Alblasserwaard, containing the windmills of Kinderdijk, a World Heritage Site Alkmaar Andijk Anna Paulownapolder Beemster, a World Heritage Site Bijlmermeer 's-Gravesloot Haarlemmermeer, containing Schiphol
airport Krimpenerwaard Lauwersmeer Mastenbroek Noordoostpolder Prins Alexanderpolder Purmer Schermer Watergraafsmeer Wieringermeer Wieringerwaard Wijdewormer Zuidplaspolder, along with Lammefjord in Denmark the lowest point of the European Union Flevopolder, the largest artificial island in the world


delta near Elbląg
and Nowy Dwór Gdański Warta
delta near Kostrzyn nad Odra


The Ankaran Polder
(Slovene: Ankaranska bonifika), Semedela Polder (Semedelska bonifika), and Škocjan Polder
(Škocjanska bonifika) in reclaimed land around Koper

South Korea[edit]

Parts of the coast of Ganghwa Island, adjacent to the river Han in Incheon Delta of the river Nakdong in Busan Saemangeum
in Jeollabuk-do

United Kingdom[edit]

Traeth Mawr Sunk Island, on the north shore of the Humber
east of Hull Parts of The Fens

Branston Island, by the River Witham
River Witham
outside the conventional area of the fens but connected to them.

Parts of the coast of Essex Some land along the River Plym
River Plym
in Plymouth Some land around Meathop
east of Grange-over-Sands, reclaimed as a side-effect of building a railway embankment The Somerset Levels
Somerset Levels
and North Somerset Levels Romney Marsh

United States[edit]

New Orleans Sacramento – San Joaquin River Delta

See also[edit]

Flood control in the Netherlands Afsluitdijk Land reclamation IJsselmeer Zuiderzee Works Windpump


^ https://books.google.com/books?id=3HjRCwAAQBAJ&dq=origin+of+phrase+%22God+created+the+world%2C+but+the+Dutch+created+the+Netherlands%22.&q=%22God+created+the+world%2C+but+the+Dutch+created+the+Netherlands%22.#v=snippet&q=%22God%20created%20the%20world%2C%20but%20the%20Dutch%20created%20the%20Netherlands%22.&f=false ^ "Kijk naar de geschiedenis". Rijkswaterstaat. Retrieved 2008-01-21. [permanent dead link] ^ Ley, Willy (October 1961). "The Home-Made Land". For Your Information. Galaxy Science Fiction. pp. 92–106.  ^ "waterschap". Archived from the original on 2012-11-02.  ^ "Bangladesh polders under threat", Irin News ^ "Bangladeshi project to enhance polders amidst climate woes" Archived 2014-04-08 at the Wayback Machine., Unearth News ^ "Rain continues to throw a challenge in Kuttanad". The Hindu. The Hindu Group. 2011. Retrieved 2011-06-10.  ^ Thampatti, Manorama (March 1999). "Rice Bowl in Turmoil: The Kuttanad
Wetland Ecosystem". Resonance. Indian Academy of Sciences. Archived from the original on 2010-12-16. Retrieved 2011-06-10.  ^ "Inch Wildfowl Reserve History". Inch and Foyle Wildfowl Project. Retrieved 5 June 2015. 

Farjon, J.M.J., J. Dirkx, A. Koomen, J. Vervloet & W. Lammers. 2001. Neder-landschap Internationaal: bouwstenen voor een selectie van gebieden landschapsbehoud. Alterra, Wageningen. Rapport 358. Morten Stenak. 2005. De inddæmmede Landskaber - En historisk geografi. Landbohistorik Selskab. Ven, G.P. van de (red.) 1993. Leefbaar laagland: geschiedenis van waterbeheersing en landaanwinning in Nederland. Matrijs, Utrecht. Wagret, P. 1972. Polderlands. London: Methuen.

External links[edit]

Wikimedia Commons has media related to Polders.

landscapes in the Netherlands
— in a northwest European and a landmark context. How to make a polder — online film

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