Offshore Gulf townships vulnerable to natural hazardsMarch 5th, 2009 - 2:47 pm ICT by IANS
Bangalore, March 5 (IANS) Reclaimed islands and offshore luxury townships coming up in the Persian Gulf are potentially vulnerable to natural hazards like earthquakes and tsunamis, warns an Indian scientist.
Although they are futuristic and novel, “there are serious issues of long-term sustainability of these townships,” cautions Arun Kumar, a professor at King Fahd University of Petroleum and Minerals in Dhahran, Saudi Arabia.
“Natural hazards have struck this region in the past and have the potential to strike again any time in the future,” Kumar says in a report published in the latest issue of Current Science.
According to the report, the United Arab Emirates (UAE), Qatar and Bahrain are spending vast sums of money on such mega urban development projects offshore that are susceptible to both geological and atmospheric hazards.
Saudi Arabia used reclamation to expand the size of Tarut Island for urban development. The city of Dubai is developing five new giant offshore island communities: The Palm Jebel Ali, The Palm Jumeirah, The Palm Deira, The World and The Universe. The Pearl Qatar is another colossal project being developed by Qatar on reclaimed land. Bahrain is also developing a similar urban development project on reclaimed land.
These townships are being built on these islands so that thousands of luxury homes, hotels, marinas, golf courses, and other types of commercial and recreational complexes including high-rise apartments can emerge.
Tropical cyclones and the resulting oceanic surges are the main possible atmospheric hazards that can strike this region at any time in the future, says Kumar. His report warns about the likelihood and possible impact of each of these unsafe events. Further, bearing global warming in mind, there is also the issue of the long-term supply of potable water to such communities.
Major urban centres in the Gulf region like Dubai are prone to dangers from earthquakes considering there are 25 seismogenic source zones in the Arabian Peninsula and adjacent countries, says Kumar. “Due to constant subduction pressure of the Arabian Plate under the Eurasian Plate, Iran and the surrounding regions are prone to high-level seismic activity,” he warns.
“The danger of earthquakes would be higher in reclaimed islands and their tall buildings because reclaimed land is potentially more susceptible to liquefaction and slope failure,” the report says. Liquefaction is a phenomenon where soils suddenly go from a solid state to a liquefied state that can happen when the ground is shaken during an earthquake.
Reclamation material here is mainly dredged carbonate sand and little is known about the underlying or nearby fracture zones and seismicity. “All these factors make tall buildings constructed on reclaimed islands quite dangerous and prone to seismic destruction.”
In the Arabian Sea, India’s Kachchh and Pakistan’s Makran coasts have in the past experienced tsunami generating earthquakes, adds Kumar. The Makran earthquake of Nov 28, 1945 and the resulting tsunami generated wave heights up to 11.5 metres and run-ups of up to 17 metres on the Makran coast. The tsunami also swept into the Gulf and washed out a large sandbar at Ras al-Khaimah in UAE.
Although tropical cyclones affecting the Arabian Peninsula and the Gulf are not common, they are becoming more frequent due to the effects of global warming, the report says. These can be severe and hazardous, as demonstrated by the cyclone Gonu which in June 2007 generated sustained winds measuring 256 km per hour.
Kumar also cautions that offshore townships built on reclaimed islands could potentially be affected by inundation and erosion due to a rise in sea-level and an increase in storm surge events.
Movement of surface and submarine currents in the Gulf poses a severe threat of erosion to these man-made islands. This means that a constant stabilisation effort will be required to sustain them, says Kumar.
“The problems of environmental pollution and algal blooms due to eutrophication within the closed water bodies due to lack of circulation, absence of currents and surface waves, and heavy input of organic waste are expected to be serious issues,” the report adds.
“I am not sure if environmental impact assessment was done for these reclaimed islands,” Kumar told IANS in an email interview. “May be they did such studies but I did not find any information in the public domain.”
(K.S. Jayaraman can be contacted at firstname.lastname@example.org)
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