Land Reclamation | 17 May 2023

Why in News?

The increasing economic importance of coastal zones, particularly in East Asia, the Middle East, and West Africa, has led to significant land reclamation projects worldwide. Despite the economic benefits, these projects face environmental challenges and potential risks from rising sea levels and storm surges.

What is Land Reclamation?

• About:
  • Land reclamation refers to the process of creating new land by altering the topography of existing bodies of water, such as seas, rivers, lakes, or marshes.
    • It is typically done along coastlines but can also occur inland, involving the conversion of wetlands or other water bodies.
  • Land reclamation has a long history of being used to expand coastal areas for agriculture and industrial purposes.
• Traditional Land Reclamation:
  • Traditionally, land reclamation meant building a series of dikes to enclose tidal marshes or shallow offshore waters and draining these enclosures to create dry land.
    • In some cases, streams were diverted to carry additional sediment into these areas, building up the land to a higher level.
    • Soil and stone could also be excavated from the mainland and dumped along the shore or on the coast of existing islands, gradually expanding the land into the sea.
• Modern Land Reclamation:
  • Today, major engineering projects involve the construction of kilometres of offshore concrete barrier walls, which are filled with substantial amounts of sand, earth, clay or rock, often shipped in from far afield.
  • The reclamation site can also be filled with dredged soil from the nearby seafloor mixed with water, in a process known as hydraulic reclamation.
• Current Extent of Land Reclamation:
  • The study, which examined satellite imagery of coastal cities with a population of at least 1 million, found that reclamation projects in 106 cities around the world had altogether created around 2,530 square kilometres (more than 900 square miles) of coastal land.
  • Nearly 90% of new coastal land was created in East Asia over the last two decades, most often to make way for industry and port facilities catering to the globalised economy.
    • From 2000 to 2020, China alone added around 350 square kilometres, with Singapore and Incheon, in South Korea, also raising vast new areas.

What are the Issues Associated with Land Reclamation?

• Coastal Flooding: Most coastal land expansion in the past couple of decades happened in low-lying areas, with more than 70% of that land “at high risk from coastal flooding between 2046 and 2100,” due in part to storm surges linked to global warming and the risk of land subsidence.
  • Stronger storms and increasingly destructive flooding are already taking coastal communities by surprise.
• Distortion of Seabed Ecosystem: Using materials like sand which are obtained from the marine and river environment can mean the destruction of habitats and spawning grounds of organisms.
  • Several countries have already banned the export of sand for land reclamation. The resulting sand shortage has forced some construction companies to extract sand and clay from the ocean floor, destroying the seabed ecosystem in the process.
• Loss of Wetlands: Coastal wetlands, such as mangroves, salt marshes, and estuaries, are highly productive ecosystems that provide numerous ecological benefits.
  • Land reclamation often involves draining or filling these wetlands, resulting in their destruction or alteration.
  • This loss of wetlands can disrupt the natural balance of coastal ecosystems, affecting water quality, fish nurseries, and the overall resilience of the coastal zone.

Way Forward

• Strategic Coastal Planning: There is a need to develop comprehensive coastal zone management plans that consider the long-term effects of land reclamation and balance economic development with environmental sustainability.
• Green Engineering Solutions: There is a need to employ innovative engineering techniques that minimise the impact of land reclamation on coastal ecosystems.
  • For example, adopting "soft" engineering solutions like permeable structures, floating islands, and sand-filled geotextile containers that allow water flow and minimise disruption to coastal processes.
• AI for Coastal Monitoring: There is a need for using artificial intelligence and remote sensing techniques to monitor coastal changes, predict erosion hotspots, and assess the effectiveness of coastal management interventions.

Source: IE