What is Land Reclamation? 

Land reclamation is a process of modifying the inherent nature of the specific land, enhancing and equipping the land to become suitable for intensive use for which it couldn’t be used earlier. Land reclamation involves reclaiming land from arid lands, swampy land, coastal areas, mine spoils, salt-affected soils, and other infertile lands. However, the extensively known and debated version of land reclamation is the creation of new inhabitable land in the sea or other water bodies and this article focuses on the development of man made islands by coastal land reclamation or reclamation from rivers and lakes.

The main objective is to create habitable land areas to meet the demands of the growing population and lack of land. But land reclamation has evolved into a symbol of pride elucidating the human superiority and ability to shape built environments, altering coastlines, and creating luxurious waterfront developments at the cost of the environment. It is ironic how humans forget that they are also a part of the environment and continue to challenge their well-being!

Historical cases of Land Reclamation- Man Made Islands

Artificial islands and land reclamation have been painted as contemporary ground-breaking developments, however, the lesser-known fact states that such entities have existed in the past. Taking a closer look at such man-made interventions for what has evolved through the years, it is only the function and the scale. Some of the precedents (existing and perished) include the floating islands of Lake Titicaca, crannogs of prehistoric Scotland and Ireland, the ceremonial centers of Nan Madol in Micronesia, Dejima (or Deshima) in the bay of Nagasaki in Japan, artificial Chinamitl islands (Chinampas) and even the floating city of Venice.  

Elaborating, the artificial Chinamitl islands are a cluster of man-made agricultural islands developed on the lake of Titicaca, during the Aztec period around the natural island and city of Tenochtitlan, or the current-day historic center of Mexico. While Chinampas were planting beds to cultivate, Nan Madol in Micronesia was a political, religious, and ceremonial center of about 100 artificial islands constructed on a lagoon joint by a canal network Saudeleur dynasty.

Further, during the Edo period, the crowded coastal city, an island, Dejima was built in the bay of Nagasaki to meet the growing demand for infrastructure that the already suffocating cities couldn’t offer. The city of Venice is another example of canal-connected artificial islands that sprouted in the Adriatic Sea in the 5th century.  

Land Reclamation Methods

Reclamation from water bodies, in simple terms is either by filling with large amounts of heavy rock and cement, clay, and soil until the desired height is reached or by draining water to create lands that in this case are mainly suitable for agriculture. Moving into the technical realms there are three methods of reclaiming land from water bodies as follows. 

Rehandling method 

The rehandling pit is a natural depression on a firm seabed that is identified or created by means of dredging. Barges are used to transport the sand that is filled temporarily in the pits that can hold up to several cubic meters of fill material. Two cutter suction hopper dredger dredges are involved in this process, of which one dredges the sand at the borrow source and transports it to the rehandling pit, while the other operates at the rehandling pit to fill the reclamation area. 

Hydraulic filling method

The hydraulic filling method is only suitable for granular fill and is generally used when filling is carried out from an offshore source. The dredger dredges the sand from the borrow source, which is transported to the reclamation area and then discharged out by pumping a mixture of water and the fill material.  

Sand spreading method

The sand spreading method is suitable when the seabed is too shallow or the seabed soil is too soft. A spreader which uses a winch system and a bulldozer for mobility, is mounted on a small floating barge and a mixture of sand and water is discharged through perforations in the pipe. 

Contemporary Land Reclamation Projects

Artificial Islands and Land Reclamation Projects have significantly found their place in the global race to develop seducing waterfront real estate developments. The countries have succumbed to the potential of land reclamation for making global statements; showcasing innovation, reshaping coastlines, creating new urban centers, and redefining the possibilities of the built environment. Amidst growing awareness and rising protests, such developments continue to mushroom.

Dubai’s Palm Jumeirah and Singapore’s Marina Bay are exclusive waterfront developments with world-class amenities and uniqueness that can’t escape the list of contemporary land reclamation projects. But there are other projects too that are massive. The Great Garuda land reclamation project of Indonesia (2014) intended to reclaim 12.5 square kilometers of land to combat the flooding in North Jakarta by developing 17 artificial islands off the island’s north coast is currently under halt occupied with other flood-mitigation measures.

Another such project is the Penang South Reclamation (PSR) project in Malaysia, facing resistance from the fishermen of the region. The government sought to deal with it with a promise of social and economic inclusion; developing 25% of the houses in affordable housing prices apart from ensuring appropriate environmental measures. Social and economic inclusion in reclaimed islands is certainly another question to be answered!

The Story of Mumbai

Mumbai is known for its dense population, unquenched thirst for building, and peak property prices. Somehow, land has always been Mumbai’s most critical commodity and this fact is still pertinent today. The present-day metropolitan Mumbai crams 21 million people into an area of 233 square miles. But why the story of Mumbai is incomplete without land reclamation?

This massive 233 square miles of land was once originally 7 islets of less than 18 square miles. Incredible isn’t it? From 7 disconnected islands to what Mumbai is today, it has seen multiple reclamations of land from the sea at different times and distinct scales. The Hornby Vellard project was one such earliest significant intervention that has shaped most of the present-day city. Beginning in 1782, the Hornby Vellard causeway project linking all seven islands, namely, Colaba, Old Woman’s Island, Bombay, Mazgaon, Parel, Mahim, and Worli was completed in 1784.

By 1845, the seven islands coalesced into a single entity by reclaiming land from the Arabian Sea as a part of the Hornby Vellard project. However, the reclamation efforts continued, even after merging the islands and even after independence. Though some of the reclamation projects in Mumbai were conceived to relax the overcrowding and to provide public spaces, they eventually turned out to be hosts to luxurious waterfront apartments.

Impacts of Land Reclamation 

While land reclamation may sort out some of the issues, having been put under the lens, the effects of artificial islands on aquatic life, marine ecosystems, and coastal dynamics, is a far from indisputable fact. Land reclamation poses a threat to the aquatic flora and fauna leading to biodiversity loss. Further, it causes a disruption in hydrodynamics (sea level, wave conditions, tidal conditions, storm surge, coastal currents, and river flow) due to a change in the shoreline. For instance, in China land reclamation has interfered with the hydrodynamics resulting in alteration of the wave dynamics, has posed a threat to the coral reefs, and also has caused a change in the migration pattern of several species. 

Moreover, land reclamation leads to water quality degradation due to sediment disturbances caused by dredging of the water bodies and underwater explosions. This also leads to high metal concentrations in water as the disturbed sediments cannot absorb the heavy metal present in the water. Similar effects are observed due to the reclamation of the ‘Palm Islands’ and The ‘World Islands’ including coastal erosion, change in wave pattern, and sediments disrupting the sunlighting reaching the marine fauna and flora, inflicting harm on them. In short, land reclamation is fighting the environment, inflicting harm on other life to ensure human sustenance and a win for innovative ideologies. 

Alternative to Man Made Islands: Floating city

While it is true that artificial islands have always served ‘a need’ in history and are viewed as ‘a pride’ in contemporary times, the continual unsustainable artificial island developments will leave the environment at stake in the long run. In the midst of the climate crisis and the call for sustainability worldwide, there is a call for an alternative solution, environmentally sound, and economically feasible, as a swap for artificial islands. Researchers identify ‘floating city’ as a sustainable and cost-efficient alternative to land reclamation, and potentially the future of building on water.

FAQ

1. What is Dredging?

Dredging is a process of excavating or removing sediment, such as sand, gravel, or mud, from the bottom of a water body, such as a lake, river, or ocean. Dredging can be performed using various methods, including suction dredging, which uses a vacuum-like system to remove sediment, and cutter suction dredging, which uses a rotating cutter to break up and remove sediment.

2. What are Barges?

Barges are large, flat-bottomed boats or vessels used for transporting goods, cargo, and even people, typically on inland waterways such as rivers, canals, and lakes. They are often self-propelled or towed by a tugboat and are commonly used for bulk transportation of goods like coal, sand, grain, and oil.