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28-740: From the Middle Ages the 'Binnendijksche Buitenveldertse' polder in the rural Amstelland region was part of the Nieuwer-Amstel municipality. In 1921, the Buitenveldert polder was annexed by the city of Amsterdam. Since then, the Kalfjeslaan on the southside of Buitenveldert has been the city limit. As part of the Algemene Uitbreidingsplan ('General Expansion Plan') of 1935, the Buitenveldert polder became

56-582: A meaning somewhat opposite to that in coastal context. IJsselmeer The IJsselmeer ( Dutch: [ˌɛisəlˈmeːr] ; West Frisian : Iselmar , Dutch Low Saxon : Iesselmeer ), also known as Lake IJssel in English, is a closed-off freshwater lake in the central Netherlands bordering the provinces of Flevoland , North Holland and Friesland . It covers an area of 1,100 km (420 sq mi) with an average depth of 4.5 m (15 ft). The river IJssel , after which

84-421: 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 with 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

112-407: A piece of land elevated above its surroundings, with the augmentative suffix -er and epenthetical -d- . The word has been adopted in thirty-six languages. 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

140-431: Is a stub . You can help Misplaced Pages by expanding it . Polder A polder ( Dutch pronunciation: [ˈpɔldər] ) is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes . The three types of polder are: The ground level in drained marshes subsides over time. All polders will eventually be below the surrounding water level some or all of

168-608: 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 become available. Major Dutch polders and the years they were laid dry include Beemster (1609–1612), Schermer (1633–1635), and Haarlemmermeerpolder (1852). Polders created as part of the Zuiderzee Works include Wieringermeerpolder (1930), Noordoostpolder (1942) and Flevopolder (1956–1968) Several cities on

196-786: The Paraíba Valley region (in the state of São Paulo ) have polders on land claimed from the floodplains around the Paraíba do Sul river. Bangladesh has 139 polders, of which 49 are sea-facing, while the rest are along the numerous distributaries of the Ganges-Brahmaputra-Meghna River delta. These were constructed in the 1960s to protect the coast from tidal flooding and reduce salinity incursion. They reduce long-term flooding and waterlogging following storm surges from tropical cyclones . They are also cultivated for agriculture. The Jiangnan region, at

224-486: The Yangtze River Delta , has a long history of constructing polders. Most of these projects were performed between the 10th and 13th centuries. The Chinese government also assisted local communities in constructing dikes for swampland water drainage. The Lijia (里甲) self-monitoring system of 110 households under a lizhang (里长) headman was used for the purposes of service administration and tax collection in

252-542: The 11th century. The oldest extant polder is the Achtermeer polder, from 1533. 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) 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

280-526: The IJsselmeer constituted the new province of Flevoland , the twelfth province of the Netherlands. The water of the IJsselmeer is now almost completely fresh, the saline having long since been purged. This altered environment has had an impact on the fish and plant ecosystems . The change has been beneficial for Dutch boats, many of which are steel, as the freshwater significantly reduces rusting of

308-520: The IJsselmeer was later closed off to form the Markermeer . From 1929 till 1967, over half the IJsselmeer was drained, creating 1,979 km (764 sq mi) of polders : Wieringermeerpolder , Noordoostpolder , East and South Flevoland . In 1975, a dyke was built between Enkhuizen and Lelystad as the northern boundary of the Markerwaard , a planned but never realized polder in

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336-530: The IJsselmeer. This dyke, the Houtribdijk or Markerwaarddijk , split the IJsselmeer into two parts. The former southern part of the IJsselmeer is now the hydrologically separate Markermeer . The proposed polderisation of the Markerwaard was abandoned after many of the Dutch population did not want the loss of the traditional seaside (now lakeside) environment and vistas. In 1986 three polders in

364-428: The air. Polders are at risk of 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

392-578: The bay. Later drainage plans focused on creating fertile farmland, but they never progressed beyond the planning stage. It was only after the flood of 1916 that the legislature approved the Zuiderzee Works , a major hydraulic engineering project that involved building dykes, draining parts of the Zuiderzee, and constructing the Afsluitdijk to keep tides and high water out. In 1932 the Zuiderzee

420-536: The closed-off bay functions as a large freshwater reservoir, serving as a source for agriculture and drinking water. Outlet sluices in the Afsluitdijk regulate the water level of the IJsselmeer. The IJsselmeer is used for transport and fishing. It also offers a number of opportunities for recreational activity, both on the water and on its shores. Due to the shallowness of the IJsselmeer, the Markermeer, and

448-454: The hulls, and there is far less build-up of marine growth (such as algae and barnacles below the barges ' waterlines). This has the knock-on benefit that barges and yachts in the IJsselmeer need far less antifouling , a coating which is inevitably somewhat toxic to wildlife. Due to considerable amounts of water from the Rhine flowing through its distributary IJssel into the IJsselmeer,

476-536: The lake and the North Sea, turning the lake into a bay of the North Sea, called the Zuiderzee . The Zuiderzee continued to be a threat to the Dutch, especially when northwesterly storms funnel North Sea waters towards the English Channel, creating very high tides along the Dutch coast. During the 17th century, Zuiderzee dykes collapsed several times, and plans were drawn up to eliminate the threat by draining

504-514: The lake was named, flows into the IJsselmeer. Two thousand years ago Pomponius Mela , a Roman geographer, mentioned a complex of lakes at the current location of the IJsselmeer. He called it Lacus Flevo . Over the centuries, the lake banks crumbled away due to flooding and wave action, and the lake, now called the Almere , grew considerably. During the 12th and 13th centuries, storm surges and rising sea levels flooded large areas of land between

532-601: The neighboring boroughs of Rivierenbuurt to form the new borough of Zuideramstel, which also included parts of the Prinses Irenebuurt. In 2010, after another merger, Buitenveldert became part of the borough of Amsterdam-Zuid . In 1998, the masterplan for the Zuidas business district was adopted by the Amsterdam municipal council. The new business district has transformed the northern part of Buitenveldert, whereas

560-551: The polder, with a liangzhang (粮长, grain chief) responsible for maintaining the water system and a tangzhang (塘长, dike chief) for polder maintenance. In Germany, land reclaimed by diking 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 . In southern Germany, the term polder is used for retention basins recreated by opening dikes during river floodplain restoration ,

588-485: 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 institutions 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

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616-799: The polders into an inaccessible swamp, which allowed the Allied armies to stop the German army . The Netherlands has a large area of polders: as much as 20% of the land area has at some point in the past been reclaimed from the sea, thus contributing to the development of the country. IJsselmeer is the most famous polder project of the Netherlands. Some other countries which have polders are Bangladesh , Belgium , Canada and China . Some examples of Dutch polder projects are Beemster , Schermer , Flevopolder and Noordoostpolder . The Dutch word polder derives successively from Middle Dutch polre , from Old Dutch polra , and ultimately from pol- ,

644-400: The site of a new suburb. It was the only suburb on the south side of the city; most other suburbs were planned on the west side. In 1958 the first stone was laid for the suburb, which was designed according to the garden city planning principles. In 1959 the first residents moved into their new homes. In 1987 Buitenveldert was granted the status of a borough . In 1998 the borough merged with

672-598: The southern part has remained mostly residential. The highlight of this residential area is the Gelderlandplein, a shopping centre with several clothing shops, jewelries, restaurants, supermarkets and others. It is one of the few shopping centres in Amsterdam but while the others, like Magna Plaza and Bijenkorf, are located in the city centre, the Gelderlandplein is in this residential area. 52°20′N 4°53′E  /  52.333°N 4.883°E  / 52.333; 4.883 This North Holland location article

700-569: 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

728-500: The time. Water enters the low-lying polder through infiltration and water pressure of groundwater , 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

756-594: The world, but the Dutch created the Netherlands". The Dutch have a long history of reclamation of marshes and fenland, resulting in some 3,000 polders nationwide. By 1961, about half of the country's land, 18,000 square kilometres (6,800 sq mi), was reclaimed from the sea. About half the total surface area of polders in northwest Europe is in the Netherlands. The first embankments in Europe were constructed in Roman times. The first polders were constructed in

784-461: Was closed off by the Afsluitdijk, a 32-kilometre (20 mi) dyke connecting Friesland and North Holland on either side of the Zuiderzee. The Zuiderzee was no longer a sea inlet and was renamed IJsselmeer ( Lake IJssel ) after the IJssel river that flows into it, which is also the namesake of the province of Overijssel . The continuing flow of fresh river water soon flushed out the salt water. Part of

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