Palm Islands on the coast of Dubai, United Arab EmiratesBy: Lovely Roy on: Mar 25, 2016 at: 16:14:24
Palm Islands are two artificial islands, Palm Jumeirah and Palm Jebel Ali, on the coast of Dubai, United Arab Emirates. As of November 2014, only Palm Jumeirah has been completed. This island takes the form of a palm tree, topped by a crescent. After completion, Palm Jebel Ali will take a similar shape; both islands will be host to a large number of residential, leisure and entertainment centres and will add a total of 520 kilometres of non-public beaches to the city of Dubai.
The creation of the Palm Jumeirah began in June 2001. Shortly after, the Palm Jebel Ali was announced and reclamation work began. A third island was planned and construction started, but this project was later remodelled and renamed to Deira Island.
The Palm Islands are artificial islands constructed from sand dredged from the bottom of the Persian Gulf by the Belgian company, Jan De Nul and the Dutch company, Van Oord. The sand is sprayed from dredging ships, guided by a Global Positioning System, onto the required area. The spraying process is known as rainbowing because of the rainbow-like arcs produced in the air when the sand is sprayed. The outer edge of each palm's encircling crescent is a large rock breakwater. The breakwater of the Palm Jumeirah contains over seven million tons of rock; each rock was placed individually by a crane, its position signed off by a diver, and given a Global Positioning System coordinate.
The Jan De Nul Group started working on the Palm Jebel Ali in 2001 and had finished by the end of 2006. The reclamation project for the Palm Jebel Ali includes the creation of a four-kilometer-long peninsula, protected by a 200-meter-wide, seventeen-kilometer long circular breakwater. There are 210,000,000 cubic meters of rock, sand and limestone that were reclaimed (partly originating from the Jebel Ali entrance channel dredging work). There are approximately 10,000,000 cubic meters of rocks in the Slope Protection Works.
1) Palm Jumeirah
The Palm Jumeirah Consists of a tree trunk, a crown with 16 fronds, and a surrounding crescent island that forms an 11 kilometer-long breakwater. The island itself is five kilometers by five kilometers. It adds 78 kilometers to the Dubai coastline.The main challenges of the installation of sub-sea horizontal directional drillings on Palm Jumeirah specifically, was that there were close spacing between the bores (holes), changing soil conditions along the drilling alignment (fill/rock) and brackish (slightly salty) groundwater. To resolve the second problem, vibrocompaction technologies were used just like in the case with sand in the palm's fronds themselves.
Besides the scientific challenges to this construction project, another challenge was the pressure to finish the islands in such a limited amount of time - 3 years. In order to keep ahead of schedule, the company constructing the islands, decided to start laying the sand foundation under the sea. Yes, time constraints forced both companies - the one constructing the breakwater crescent, and the one constructing the islands to complete both structures simultaneously. However, eight months into the project, it wanted to bring them above sea level. In April 2002, after 550 m of the breakwater crescent was completed, the company finally brought out the fronds. This decision was based on a study conducted that sought to minimize constructions risks, to be elaborated below. It explains the different sediment transport processes that occurred during construction time.
Residents began moving into Palm Jumeirah properties at the end of 2006, five years after land reclamation began.The Palm Island address is considered a status symbol in Dubai.
A Monorail opened in 2009, but is not connected to other public transport.
2) Palm Jebel Ali
The Palm Jebel Ali began contruction in October 2002 and was expected to be completed in 2016 and was originally planned to be completed by mid-2008 and has been on hold since.
The project, which is 50 percent larger than the Palm Jumeirah, is proposed to include six marinas, a water theme park, 'Sea Village', homes built on stilts above the water, and boardwalks that circle the "fronds" of the "palm" .
The construction of the Palm Islands has had a significant impact on the surrounding environment, resulting in changes to area wildlife, coastal erosion, alongshore sediment transport and wave patterns. Sediment stirred up by construction has suffocated and injured local marine fauna and reduced the amount of sunlight which filters down to seashore vegetation. Variations in alongshore sediment transport have resulted in changes in erosion patterns along the UAE coast, which has also been exacerbated by altered wave patterns as the waters of the Gulf attempt to move around the new obstruction of the islands.
Dubai's megaprojects have become a favorite cause of environmentalists. Greenpeace has criticized the Palm Islands for lack of sustainability, and Mongabay.com, a site dedicated to rain forest conservation, has attacked Dubai's artificial islands aggressively, stating that:significant changes in the maritime environment [of Dubai] are leaving a visual scar ,As a result of the dredging and redepositing of sand for the construction of the islands, the typically crystalline waters of the gulf of Dubai have become severely clouded with silt. Construction activity is damaging the marine habitat, burying coral reefs, oyster beds and subterranean fields of sea grass, threatening local marine species as well as other species dependent on them for food. Oyster beds have been covered in as much as two inches of sediment, while above the water, beaches are eroding with the disruption of natural currents.
Project risks and threats
1) Waves 2 meters high.
2) Storm frequency of 1 in 1 year.
3) Earthquakes from 6 to 7 on the Richter scale.
4) Weak soil due to constant exposure to rising sea water.
5) Water pollution.
1) Erosion(caused by winds and water currents) is one of the biggest problems present, as it strips away the sand which forms the majority of the island.
2) Damage to the marine ecology (e.g. the loss of reefs and fish), including disturbances in the reproductive cycles of the species of fish that were close to the shores of Dubai. Research conducted by marine biologists on this phenomenon showed that the newly-born fish were not able to survive in conditions along the shores of Dubai due to constant construction and environmental alterations (e.g. shifting of sand, moving boulders and the effects of the vibrators used to compact the sand and soil).
3)Due to the shape of the island right outside the coast of Dubai, there is loss of coastal shape along the seashore of Dubai.
Remedial measure to protect the coast
To properly manage their shorelines and effects, Dubai relies on its coastal monitoring program. Established in 1997, the Dubai coastal monitoring program began studying the baseline bathymetric (measurement of depth of water in oceans or seas) and topographic survey of the Jumeirah (Dubai) coastline.
Additional data were collected with technological improvements including remote video monitoring of Dubai beaches, sediment sampling and analysis, near shore directional wave and current recordings and intensive measurement exercises at selected locations using Acoustic Doppler Current Profiler (ADCP) equipment. This way they were able to do a constant monitor and check on the continuously changing environmental conditions along the coast of Dubai.