Land reclamation, often known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new land from oceans, seas, riverbeds or lake beds. The land reclaimed is known as reclamation ground, reclaimed land, or land fill.
In Ancient Egypt, the rulers of the Twelfth Dynasty (c. 2000–1800 BC) undertook a far-sighted land reclamation scheme to increase agricultural output. They constructed levees and canals to connect the Faiyum with the Bahr Yussef waterway, diverting water that would have flowed into Lake Moeris and causing gradual evaporation around the lake's edges, creating new farmland from the reclaimed land. A similar land reclamation system using dams and drainage canals was used in the Greek Copaic Basin during the Middle Helladic Period (c. 1900–1600 BC). [1] One of the earliest large-scale projects was the Beemster Polder in the Netherlands, realized in 1612 adding 70 square kilometres (27 sq mi) of land. In Hong Kong the Praya Reclamation Scheme added 20 to 24 hectares (50 to 60 acres) 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. [2] Some 20% of land in the Tokyo Bay area has been reclaimed, [3] most notably Odaiba artificial island. The city of Rio de Janeiro was largely built on reclaimed land, as was Wellington, New Zealand.
Land reclamation can be achieved by a number of different methods. The simplest method involves filling the area with large amounts of heavy rock and/or cement, then filling with clay and dirt until the desired height is reached. The process is called "infilling" [4] and the material used to fill the space is generally called "infill". [5] [6] Draining of submerged wetlands is often used to reclaim land for agricultural use. Deep cement mixing is used typically in situations in which the material displaced by either dredging or draining may be contaminated and hence needs to be contained. Land dredging is also another method of land reclamation. It is the removal of sediments and debris from the bottom of a body of water. It is commonly used for maintaining reclaimed land masses as sedimentation, a natural process, fills channels and harbors. [7]
Agriculture was a driver of land reclamation before industrialisation. [26] In South China, farmers reclaimed paddy fields by enclosing an area with a stone wall on the sea shore near a river mouth or river delta. The species of rice that are grown on these grounds are more salt tolerant. Another use of such enclosed land is the creation of fish ponds. It is commonly seen on the Pearl River Delta and Hong Kong. These reclaimed areas also attract species of migrating birds.
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.
Even in the post-industrial age, there have been land reclamation projects intended for increasing available agricultural land. For example, the village of Ogata in Akita, Japan, was established on land reclaimed from Lake Hachirōgata (Japan's second largest lake at the time) starting in 1957. By 1977, the amount of land reclaimed totalled 172.03 square kilometres (66.42 sq mi). [27]
Artificial islands are an example of land reclamation. Creating an artificial island is an expensive and risky undertaking. It is often considered in places with high population density and a scarcity of flat land. 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 (although there is yet no real "scarcity of land" in Dubai), as well as the Flevopolder in the Netherlands which is the largest artificial island in the world.
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. An example of this is the city of Mumbai. [10]
As human overcrowding of developed areas intensified during the 20th century, it has become important to develop land re-use strategies for completed landfills. Some of the most common usages are for parks, golf courses and other sports fields. Increasingly, however, office buildings and industrial uses are made on a completed landfill. In these latter uses, methane capture is customarily carried out to minimize explosive hazard within the building.
An example of a Class A office building constructed over a landfill is the Dakin Building at Sierra Point, Brisbane, California. The underlying fill was deposited from 1965 to 1985, mostly consisting of construction debris from San Francisco and some municipal wastes. Aerial photographs prior to 1965 show this area to be tidelands of the San Francisco Bay. A clay cap was constructed over the debris prior to building approval. [28]
A notable example is Sydney Olympic Park, the primary venue for the 2000 Summer Olympic Games, which was built atop an industrial wasteland that included landfills.
Another strategy for landfill is the incineration of landfill trash at high temperature via the plasma-arc gasification process, which is currently used at two facilities in Japan, and was proposed to be used at a facility in St. Lucie County, Florida. [29] The planned facility in Florida was later canceled. [30]
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. Reclamation projects have strong negative impacts on coastal populations, although some species can take advantage of the newly created area. [31] A 2022 global analysis estimated that 39% of losses (approximately 5,300 km2 or 2,000 sq mi) and 14% of gains (approximately 1,300 km2 or 500 sq mi) of tidal wetlands (mangroves, tidal flats, and tidal marshes) between 1999-2019 were due to direct human activities, including conversion to aquaculture, agriculture, plantations, coastal developments and other physical structures. [32]
The State of California created a state commission, the San Francisco Bay Conservation and Development Commission, in 1965 to protect San Francisco Bay and regulate development near its shores. The commission was created in response to growing concern over the shrinking size of the bay.
Hong Kong legislators passed the Protection of the Harbour Ordinance, proposed by the Society for Protection of the Harbour, in 1997 in an effort to safeguard the increasingly threatened Victoria Harbour against encroaching land development. [33] Several large reclamation schemes at Green Island, West Kowloon, and Kowloon Bay were subsequently shelved, and others reduced in size.
Reclaimed land is highly susceptible to soil liquefaction during earthquakes, [34] which can amplify the amount of damage that occurs to buildings and infrastructure. Subsidence is another issue, both from soil compaction on filled land, and also when wetlands are enclosed by levees and drained to create polders. Drained marshes will eventually sink below the surrounding water level, increasing the danger from flooding.
Country or territory | Notes |
---|---|
Bahrain | 76.3% of original size of 410 km2 (160 sq mi) (1931–2007). [ citation needed ] [35] |
Bangladesh | About 110 km2 (42 sq mi) in total and has 12,000 square kilometres (4,600 sq mi) potential (8% of total area) up to 12 metres (39 ft) depth in the territorial sea area. [36] |
Hong Kong | 67 km2 (26 sq mi) of land was reclaimed up to 2013. Praya Reclamation Scheme began in the late 1860s and consisted of two stages totaling 20 to 24 hectares (50 to 60 acres). [2] 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, [37] as well as the collusion of the Hong Kong Government with the real estate developers in the territory. [38] [39] In addition, as the city expanded, new towns in different decades were mostly built on reclaimed land, such as Kwun Tong, Sha Tin-Ma On Shan, Tai Po, Tseung Kwan O, Tuen Mun, and West Kowloon. |
India | Mumbai – An archipelago of originally seven separate islands were joined by land reclamation over a span of five centuries. This was done to develop Mumbai as a harbour city. |
Indonesia | Jakarta – Giant Sea Wall Jakarta is part of a massive coastal development project at Jakarta Bay. |
Japan | |
Macao | 170% of the original size or 17 km2 (6.6 sq mi) [41] |
North Korea | In the 1980s, North Korea commenced a "find new land" program to reclaim 300,000 hectares of land (3,000 km2 or 1,160 mi2) in order to expand the country's supply of arable land. The project was unsuccessful and only reclaimed 20,000 hectares (200 km2 or 70 mi2) by the time it was cancelled after the death of Kim Il-sung in 1994. It also contributed to the collapse of the North Korean economy and the subsequent famine in the 1990s. Land reclamation efforts resumed in the 2010s under Kim Jong-un with more success. North Korea constructed artificial islands in the Yellow Sea containing Korean People's Army bases, possibly inspired by Chinese artificial islands in the South China Sea and possibly as bases for long-range ballistic missiles. [42] [43] [44] |
Philippines |
|
Singapore | 20 percent of the original size or 135 km2 (52 sq mi). As of 2003 [update] , plans for 99 km2 (38 sq mi) more are to go ahead, [46] even though disputes persist with Malaysia over Singapore's extensive land reclamation works. [47] Parts of Changi Airport are also on reclaimed land. |
South Korea | As of 2006, 38 percent or 1,550 km2 (600 sq mi) of coastal wetlands reclaimed, including 400 km2 (150 sq mi) at Saemangeum. Songdo International Business district, the largest private development in history, is a large-scale reclamation project built entirely on tidal mudflats. |
United Arab Emirates | Dubai has a total of four reclaimed islands (the Palm Jumeirah, Jebal Ali, The Burj al Arab Island, and The World Islands), with a fifth under construction (the Palm Deira). There are several human-made islands in Abu Dhabi, such as Yas Island and Al Lulu Island. |
Country | Notes |
---|---|
Monaco | 0.41 km2 (0.16 sq mi) out of 2.05 km2 (0.79 sq mi), or one fifth of Monaco comes from land taken from the sea, mainly in the neighborhoods of Fontvieille, La Condamine, and Larvotto/Bas Moulins. |
Netherlands | About 1/6 (almost 17%) of the entire country, or about 7,000 km2 (2,700 sq mi) in total, has been reclaimed from the sea, lakes, marshes and swamps. The province of Flevoland has almost completely been reclaimed from the Zuiderzee. |
Country | Notes |
---|---|
New Zealand | Significant areas of land totaling several hundred hectares have been reclaimed along the harbourfronts of Auckland, Dunedin, and Wellington. In Dunedin – which in its early days was nicknamed "Mudedin" – around 2.5 km2 (0.97 sq mi), including much of the inner city and suburbs of Dunedin North, South Dunedin, and Andersons Bay is reclaimed from the Otago Harbour, and a similar area in the suburbs of St Clair and St Kilda is reclaimed swampland. The international airports serving Auckland and Wellington have had significant reclamation for runway use. [48] [49] |
Nigeria | Eko Atlantic, [50] Lagos – 25 square kilometers |
Country or territory | Reclaimed land (km2) | Notes |
---|---|---|
China | 13,500+ km2 | Land reclamation in China |
Netherlands | 7,000 km2 | Flevoland, de Beemster, Afsluitdijk Land reclamation in the Netherlands |
South Korea | 1,550 km2 | |
United States | 1,000+ km2 | Artificial islands of the United States |
Japan | 500+ km2 | |
United Arab Emirates | 470 km2 | Land reclamation in the United Arab Emirates |
Bahrain | 410 km2 | |
Singapore | 135 km2 | Land reclamation in Singapore |
Bangladesh | 110 km2 | |
Hong Kong | 67 km2 | Land reclamation in Hong Kong |
Qatar | 35 km2 | |
Macao | 17 km2 | |
Philippines | 9.26 km2 | Cebu South Road Properties Central Business District and Land reclamation in Metro Manila |
New Zealand | 3.3 km2 | Reclamation of Wellington Harbour [51] |
Sri Lanka | 2.33 km2 | Colombo International Financial City [52] [ circular reference ] |
South Africa | 1.94 km2 | Cape Town Foreshore [53] |
Maldives | 0.62 km2 | Velana International Airport [54] |
Monaco | 0.41 km2 | Land reclamation in Monaco |
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The Hong Kong Special Administrative Region (HKSAR), can be divided into three geographical regions: Hong Kong Island, Kowloon, and the New Territories. Hong Kong is a coastal city, bordering Guangdong Province through the city of Shenzhen to the north and the South China Sea to the east, south, and west. Hong Kong and its 260 nearby islands and peninsulas are located at the mouth of the Pearl River Delta. The area of Hong Kong is distinct from Mainland China, but is considered a part of "Greater China".
A polder 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:
Jamaica Bay is an estuary on the southern portion of the western tip of Long Island, in the U.S. state of New York. The estuary is partially man-made, and partially natural. The bay connects with Lower New York Bay to the west, through Rockaway Inlet, and is the westernmost of the coastal lagoons on the south shore of Long Island. Politically, it is primarily divided between the boroughs of Brooklyn and Queens in New York City, with a small part touching Nassau County.
Tokyo Bay is a bay located in the southern Kantō region of Japan spanning the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. The Tokyo Bay region is the most populous and the largest industrialized area in Japan.
The Kowloon Peninsula is a peninsula that forms the southern part of the main landmass in the territory of Hong Kong, alongside Victoria Harbour and facing toward Hong Kong Island. The Kowloon Peninsula and the area of New Kowloon are collectively known as Kowloon.
An artificial island or man-made island is an island that has been constructed by humans rather than formed through natural processes. Other definitions may suggest that artificial islands are lands with the characteristics of human intervention in their format process, while others argue that artificial islands are created by expanding existing islets, constructing on existing reefs, or amalgamating several islets together. Although constructing artificial islands is not a modern phenomenon, there is no definite legal definition of it. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those that support entire communities and cities. Archaeologists argue that such islands were created as far back as the Neolithic era. Early artificial islands included floating structures in still waters or wooden or megalithic structures erected in shallow waters.
Kowloon Bay is a bay within Victoria Harbour and an neighbourhood within Kowloon, Hong Kong.
Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing dams, dikes, and other controls for streams and shorelines; and recovering valuable mineral deposits or marine life having commercial value. In all but a few situations the excavation is undertaken by a specialist floating plant, known as a dredger.
Kau Yi Chau, also known as Tai Kau Yi Chau, is an uninhabited island located west of Victoria Harbour, between Peng Chau and Green Island in Hong Kong. It is located on the crossroad of sea routes, east to west and north to south. The ferry between Central and Mui Wo sails close to the south of the island. Administratively it is part of Islands District.
Serangoon Harbour is a harbour in Singapore located between the mainland island of Singapore and Pulau Ubin.
Central and Wan Chai Reclamation is a project launched by the government of Hong Kong since the 1990s to reclaim land for different purposes. This includes transportation improvements such as the Hong Kong MTR station, Airport Express Railway & Central-Wan Chai Bypass, as well as public recreation space such as the Central Harbourfront Event Space, Tamar Park and the Hong Kong Observation Wheel.
Penta-Ocean Construction Co., Ltd. is a major Japanese construction firm. It specializes in marine works and land reclamation.
Since 1949, China has carried out extensive land reclamation projects. It is among the countries which have built the most artificial land; from 1949 to 1990s, the total area of land reclaimed from the sea of China was about 13,000 km2.
The reclamation of land from the ocean has long been used in mountainous Hong Kong to expand the limited supply of usable land with a total of around 60 square kilometres of land created by 1996. The first reclamations can be traced back to the early Western Han dynasty, when beaches were turned into fields for salt production. Major land reclamation projects have been conducted since the mid-19th century.
Dredging, Environmental and Marine Engineering NV (DEME) is an international group of specialised companies in the fields of capital and maintenance dredging, land reclamation, port infrastructure development, offshore related services for the oil & gas industry, offshore windfarm installation, and environmental remediation. The group is based in Zwijndrecht, Belgium, and has current operations on five continents.
The Las Piñas–Parañaque Critical Habitat and Ecotourism Area (LPPCHEA), also known as the Las Piñas–Parañaque Wetland Park, is a protected area at the coasts of the cities of Las Piñas and Parañaque in Metro Manila, Philippines. The entire wetland is a declared Ramsar site under the Ramsar Convention of UNESCO.
The reclamation of land from surrounding waters is used in Singapore to expand the city-state's limited area of usable, natural land. Land reclamation is most simply done by adding material such as rocks, soil and cement to an area of water; alternatively, submerged wetlands or similar biomes can be drained.
Lantau Tomorrow Vision, also known as the Kau Yi Chau Artificial Islands, is a postponed development project in Hong Kong proposed by two former Chief Executives of Hong Kong. Former Chief Executive Carrie Lam proposed in her 2018 policy address the creation of a third core business district by constructing artificial islands with a total area of about 1,700 hectares through massive land reclamation near Kau Yi Chau and Hei Ling Chau of the eastern waters of Lantau Island. The project has been met with controversy and opposition due to environmental concerns and also its high cost of an estimated HK$580 billion, amounting to half of the city's fiscal reserves. In February 2024 the financial secretary said the project would be postponed after looking at its finances, but insisted it would not be cancelled.
The expansion of the land area of Lower Manhattan in New York City by land reclamation has, over time, greatly altered Manhattan Island's shorelines on the Hudson and East rivers as well as those of the Upper New York Bay. The extension of the island began with European colonialization and continued in the 20th century. Incremental encroachment, landfill, as well as major infrastructure have added acreage to the island. Since the passage of the Rivers and Harbors Act of 1899 all projects which extend into navigable waterways follow federal regulation and are overseen by the United States Army Corps of Engineers.