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Land reclamation
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Land reclamation is either of two distinct practices. One involves creating new land from sea- or riverbeds, the other refers to restoring an area to a more natural state (such as after pollution, desertification or salination have made it unusable).
and reclamation can be the creation of new land where there was once water.
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Land reclamation is either of two distinct practices. One involves creating new land from sea- or riverbeds, the other refers to restoring an area to a more natural state (such as after pollution, desertification or salination have made it unusable).
Creating new land
For habitation or agriculture
Land reclamation can be the creation of new land where there was once water. Notable examples in the West include parts of New Orleans; Washington, D.C. (which is partially built on land that was once swamp); Mexico City (which is situated at the former site of Lake Texcoco); Helsinki (of which the major part of the city center is built on reclaimed land); the Cape Town foreshore; the Chicago shoreline; the Manila Bay shoreline; Back Bay, Boston, Massachusetts; Battery Park City, Manhattan; the port of Zeebrugge in Belgium; the polders of the Netherlands; and the Toronto Islands, Leslie Street Spit, and the waterfront in Toronto. In the Far East, Japan, the southern Chinese cities of Hong Kong, Shenzhen and Macau, and the city-state of Singapore, where land is in short supply, are also famous for their efforts on land reclamation. One of the earliest and famous project was the Praya Reclamation Scheme, which added 50 to of land in 1890 during the second phase of construction. It was one of the most ambitious projects ever taken during the Colonial Hong Kong era. Some 20% of land in the Tokyo Bay area has been reclaimed. Monaco and the British territory of Gibraltar are also expanding due to land reclamation. The city of Rio de Janeiro was largely built on reclaimed land.
Artificial islands are an example of land reclamation. Creating an artificial island is an expensive and risky undertaking. It is often considered in places that are densely populated and flat land is scarce. Kansai International Airport (in Osaka) and Hong Kong International Airport are examples where this process was deemed necessary. The Palm Islands, The World and hotel Burj al-Arab off Dubai in the United Arab Emirates are other examples of artificial islands.
A related practice is the draining of swampy or seasonally submerged wetlands to convert them to farmland. While this does not create new land exactly, it allows commercially productive use of land that would otherwise be restricted to wildlife habitat. It is also an important method of mosquito control.
For beach restoration
Beach rebuilding is the process of repairing beaches using materials such as sand or mud from inland. This can be used to build up beaches suffering from beach starvation or erosion from longshore drift. It stops the movement of the original beach material through longshore drift and retains a natural look to the beach. Although it is not a long-lasting solution, it is cheap compared to other types of coastal defences.
Environmental impact
Draining wetlands for ploughing, for example, is a form of habitat destruction. In some parts of the world, new reclamation projects are restricted or no longer allowed, due to environmental protection laws.
Environmental legislation
Hong Kong legislators passed the Protection of the Harbour Ordinance in 1996 in an effort to safeguard the increasingly as threatened Victoria Harbour against encroaching land development.
Land amounts added
- Netherlands - about 1/5 land from land reclamation or about 7.000kmē.
- South Korea - As of 2006, 38 percent or 1,550kmē of coastal wetlands reclaimed.
- Singapore - 20% of the original size or 135 kmē as of 2003, plans for 99 kmē more.
- Hong Kong - Praya Reclamation Scheme began in the late 1860s that consisted of two stage totaling 50 to 60+ acres. This figure understates the importance of the sites reclaimed: Hong Kong Disneyland, Hong Kong International Airport, and its predecessor, Kai Tak Airport, were all built on reclaimed land. In addition, much reclamation has taken place in prime locations on the waterfront on both sides of Victoria Harbour. This has raised environmental issues of the protection of the harbour which was once the source of prosperity of Hong Kong, traffic congestion in the Central district, as well as the collusion of the Hong Kong Government with the real estate developers in the territory.
- In addition, as the city expands, new towns in different decades were mostly built on reclaimed land, such as Tuen Mun, Tai Po, Shatin-Ma On Shan, West Kowloon, Kwun Tong and Tseung Kwan O.
- Macau - 170% of the original size or 17 kmē
- Tokyo Bay, Japan - 249 kmē.
- Kobe, Japan - 23 kmē (1995).
- Bahrain - 76.3% of original size of 410 km2(1931-2007).
See also
Repairing damaged land
Land reclamation or Land rehabilitation is also the process of cleaning up a site that has sustained environmental degradation, such as those by natural cause (desertification, ...) and those caused by human activity (strip mining, ...). Land reclamation is often done in these sites to allow for some form of human use (such as a housing development) or to restore that area back to its natural state as a wildlife habitat home.
Reclaiming desert land
Land reclamation in deserts involves
- setting-up reliable water provisioning (eg by digging wells or placing long-distance water pipes)
- stabilizing and fixating the soil
Stabilizing and fixating the soil is usually done in several phases.
The first phase is fixating the soil to such extent that dune movement is ceased. This is done by grasses, and plants providing wind protection such as shelterbelts, windbreaks and woodlots. Shelterbelts are wind protections composed of rows of trees, arranged perpendicular to the prevailing wind, while woodlots are more extensive areas of woodland.
The second phase deals about improving/enriching the soil by planting nitrogen-fixating plants and using the soil immediately to grow crops. Nitrogen fixating plants used include clover, yellow mustard, beans, ... and food crops include wheat, barley, beans, peas, sweet potatoes, date, olives, limes, figs, apricot, guave, tomato, certain herbs, ... Regardless of the cover crop used, the crops (not including any trees) are each year harvested and/or plowed into the soil (eg with clover, ...); in addition a each year the plots are used for a another type of crop (known as crop rotation) to prevent depleting the soil on specific trace elements.
External links
- , provides free downloads of software and articles on land drainage.
- - A non-profit organization dedicated to sustainable conservation and the rehabilitation of damaged ecosystems.
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