Land Reclamation

Definition:

  • The process of creating new land from oceans, seas, riverbeds or lake beds

Benefits

  • Increase the availability of arable land
  • Expanding the carrying capacity of land
  • A feasible solution to the problem of overcrowding
  • It allows for further growth of a country's industry
  • Reclaimed land can be used for a multitude of purposes

Pros & Cons

Pros

  • Increase land area for a certain country
  • More spaces to build infrastructure for development
  • Can reclaimed lot of lands from flooding

Land Reclamation Method

Cons

  • Damaging to corals and marine life due to wrong selection of poor knowledge of the subject
  • Deteriorate soil and water quality
  • Impair ecosystem functioning and services

Draining of submerged land method

Deep Cement Mixing

  • Used when the material displaced by either dredging or draining may be contaminated and hence needs to be contained.

Infilling Method

  • The most simple method involves filling the area with large amounts of heavy rocks and/or cement
  • The material used to fill the area is generally called ‘infill’.

Land Dredging

  • Removal of sediments and debris from the bottom of water
  • Commonly used for maintaining reclaimed land masses ad sedimentation, a natural process, fills channels .

Example 1 :


Dubai2


  • The Palm Jumeirah, Dubai
  • Project cost: $12bn (£8.5bn)
  • Land reclaimed: 5.6km2

Example 2:-


hongkong


  • Lantau Tomorrow Vision, Hong Kong
  • Project cost: HK$624bn (£57bn)
  • Land to be reclaimed: 18km2

Land Reclamation Technique


Hydraulic Reclamation

  • Used for carried filling out from an offshore source/ rehandling pit/ from dredger

Dry Method

  • This methods suitable for filing material from land sourse, especially rock, hillcut and clay fill
  • However, this method can be vulnerable to soil liquefaction when there is seismic activity.

Direct Pumping

  • Used when the seabed is deep or the underlying seabed soil is soft

Rehandling Pit Method

  • It is transporting sand by barge and dumping the fill material like clay or rock just temporary in the pit for storage
  • The pits capacity is usually million cubic meter

Dredging

  • Removal of sediments from underwater which involving excavation process
  • Soil and rocks are excavated for channel and harbor deepening and for land reclamation
    Video Link

Sand Spreading

  • Used when the seabed is deep or the underlying seabed soil is soft

Process:-

  1. By floating equipment like dredger, fill material dredger from a borrow or dredging area
  2. Transfer the fill to the reclamation site by dredger, barge, pipeline
  3. Place fill material as mixture and process water in the reclamation area
  4. Fill material ratio adjusted following the grain size of fill material