Friday, Dec 07, 2007
Gulf News
The ocean is eating away at the coast at a rate of 50 metres every two years according to data collected, so a battle to reclaim land to protect homes and provide beaches is going on.
Without five-tonne bags of sand strategically positioned 100 metres from the shore to form protective groynes the recently nourished Umm Suqeim I beach would wash away, potentially taking houses along with it.
To combat coastal erosion caused by the impact of the sea, 500,000 cubic metres of sand has been poured along the shore to pad out the receding coastline in the past year, said Alya Abdulrahim Abdullah, head of the coastal management section at Dubai Municipality (DM).
The area under her authority stretches between the Sharjah and Abu Dhabi border, almost 70 kilometres, 10 nautical miles offshore and 1 kilometre inland. This area is defined as Dubai Coastal Zone.
Wave forecasting
www.dubaicoast.aeThe site is also used by contractors as well as by beachgoers and kite surfers who rely on the 30-minute feeds for wind and wave conditions.
This data is captured by an Acoustic Doppler Current Profiler (ADCP) located at a depth of about 8 metres, about 200 metres offshore of the Jumeirah Open Beach breakwater.
By using the information collected engineers have been able to find the best positions for groynes and breakwaters to stop the sand from being washed away.
"Numerical wave forecasting and shoreline modelling are the basis for planning coastal protection schemes that should solve the problem of holding the sand for a few years at least. We are looking for short and medium-term solutions, let's say five years ahead, because in Dubai things change so fast," said Alya.
Coastal development guidelines for all developers are also in the pipeline and will be released early 2008, she added. As for the question of erosion, the problem is chronic and has always occurred along the Dubai coast, said Alya.
"The megaprojects have caused some erosion but we had severe erosion in many areas before these projects. Because of The World, the coastline is more protected but now the sand is just shifting in a different direction."
In some areas the beaches have moved several times already to the city's edge and back again, said Giarrusso.
Coastal zone monitoringIn Umm Suqeim alone, 150,000 cubic metres of sand has been dumped and sand bags of between two and five tonnes will form groynes to protect and stabilise the beach, said Giarrusso.
Eye in the sky surveyThe zone covers the entire extent of Dubai Creek as well as Al Mamzar Lagoon and any other excavated water connected to the Arabian Gulf.
CamerasTwo cameras positioned on the 17th floor of the Burj Al Arab facing opposite directions help monitor the coastline.
www.dubaicoast.org for internet surfers to monitor the waves.
In future, nine more cameras will be positioned along the coastline from Dubai creek to Dubai Marina. At Jumeirah Open Beach, a radio receiver on the meteorological tower captures all the data sent by the Acoustic Doppler Current Profiler (ADCP).
By Emmanuelle Landais
Gulf News 2007. All rights reserved.
