High land Values
Land reclamation is commonly undertaken around coastal cities such as Singapore and Hong Kong as land values are excessive thereby costs are justified by estate developers. What is not highlighted is that ocean water behaviours including tidal accumulation, sea level rise, connection to wetlands and aquatic biodiversity determine the success or failure of land reclamation ventures.
Defying the Waves
Obstruction of natural ocean currents causes water to find its way by enhancing wave action and tides thereby naturally shifting in fresh direction with additional force.
Credit ; ArchDaily
Port City of Busan Reclamation Project
South Korea’s Port and marine city was built in the 1980’s as a result of coastal reclamation facing the sea on three sides and boasting luxurious residential high rises. The reclamation not only altered the shape of the coastline but also introduced hard land including concrete and asphalt into the ocean making the city more vulnerable to large storms and sea-level rise evident in the coastal city being ravaged by successive typhoons causing waves to spill over the seawalls and flooding low lying city localities.
Credit ; Hydroinformative Institute
Shanghai Reclamation Venture
The Shanghai coastal city urban design retained the role of wetlands as a buffer between the ocean and the land by employing sensitive land reclamation techniques which helped absorb much of the ocean’s force. Eliminating natural flooding erosion systems of wetlands can lead to extensive flooding and on the other hand preventing flooding in one location can cause water to find a new direction which leads to flooding elsewhere.
Credit; istockphoto
Hong Kong
The island of Hong Kong went about reclamation in an environmentally sustainable manner and the amount of inevitable toxic silt generated when reclaiming land was negligible as the inverse of the philosophy of a “develop first, preserve later” mentality was adopted.
Kingdom of Saudi Arabia
No effective land reclamation policy and strategy is available in the Saudi Arabian peninsula. What the planners conveniently ignored is that wetlands are not only buffers for flooding and erosion but also habitats for unique aquatic species. Marine ecology zones house coral reefs, horseshoe crabs, seaweed beds and other species near the coast. These organisms have a major impact on the ocean’s food chain and potential of commercial fishing and overall biodiversity.
Manila Bay
Manila Bay manages commerce and trade of the city through its natural harbor feature and has long been regarded as the exponent of Philippines’ socio-economic development.Reclaimed lands are the primary reason for the rise of the water level on the bay causing massive flooding and storm surges in low-lying poor localities and cities.
Karachi
A petition was filed in the High Court of Sindh , Suit No. 2316 of 2021, in which it was pleaded that no Environmental Impact Analysis of unwarranted reclamation and urbanisation initiatives was carried out and that such a massive reclaiming exercise poses serious danger to Karachi Port as underground sand is tilting towards the port, reducing water’s depth requiring continuous and costly dredging .No study on suspended sediments affects has ever been undertaken by the defendants. This was alleged a “Grab as much as possible land” initiative.Reclamation causes significant change in wave patterns, which in turn can alter the change in direction and magnitude along the coast resulting in transportation of sediments which usually leads to either massive erosion of shoreline at certain locations and may also cause siltation or deposition. If the reclamation site is near a marine reserve or marine habitat the natural flow of sand transport combined with excess sand from the reclamation always shows adverse impacts on marine life. Sea level rise is ongoing for global warming and is to be kept as a critical design factor in any coastal development .Reclamation if done near the coastal lagoons can block the inlets between lagoons and ocean causing increased flooding of urban areas. Tidal flushing from the ocean becomes non-existent which is highly detrimental to marine ecosystems and depletes fish species. It was pleaded that no hydrodynamic and sediment transport modeling, reclamation based on design waves, currents, sea levels from numerical models, geotechnical studies, ecological studies and environmental impact studies for any such endeavours was carried out prior. Reliance was placed on a Supreme Court of Pakistan judgement cited as 2020 SCMR 513 (Naimatullah Khan Advocate and others v. Federation of Pakistan) .
Acid Sulphate Soils & Blacklisting of Ports
Mangrove muds are typically potential acid sulfate soils. The best management technique for reclamation in tidal areas is to avoid exposing the mud to the air. Other techniques include re-covering the mud with water immediately after disturbance and/ or liming to neutralise any sulfuric acid formed (costly for large areas). Sediments that contain iron sulfides and with a potential to oxidize and produce acid following disturbance are found in low-lying coastal areas such as mangrove forests, salt marshes, estuaries, tidal lakes and coastal floodplains. Management and rehabilitation of an area badly affected by acid leachate will most likely be time consuming and costly, if possible. In some areas of Australia soils drained 100 years ago are still releasing acid. Hence, the Karachi Comprehensive Coastal Development Zone (KCCDZ) in the port’s Eastern Backwaters, needs to be independently reviewed in this perspective of acidification of port waters which also leads to hull corrosion and possible blacklisting of Karachi ports by the International Maritime Organisation.
Dubai Plays Smart to Attract Tourists
The Emirate of Dubai had only 70 km of coastline so huge land reclamation projects were initiated to develop luxury residential estates to attract tourism. The man made island of Palm Jumeirah , spread over 110 million m3 of dredged material and sand was completed in the year 2005. However coral reefs and oyster beds were buried with sediment which had a catastrophic effect on the marine ecosystem and lowered commercial fish catches. Coral reefs also acted as a buffer to storm surges.Breakwaters constructed to protect Palm Jumeirah are under continuing threats of coastal erosion as the sea fights to return to its natural state.
Author : Nadir Mumtaz
Credit ; Sources
http://www.karachiurbanlab.com
https://www.ctc-n.org/technology-library/protection-hard-engineering/land-claim
https://caselaw.shc.gov.pk/caselaw/view-file/MTU0NzYwY2Ztcy1kYzgz
https://tamug-ir.tdl.org/server/api/core/bitstreams/23754cab-6bcc-4da7-b172-15da085b4c31/content
https://nt.gov.au/__data/assets/pdf_file/0011/228989/environmental-guidelines.pdf
https://www.mdpi.com/2073-4441/14/16/2546
https://www.archdaily.com/1002420/how-water-responds-to-land-reclamation-in-coastal-cities
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