To maintain the existing coastline, hundreds of tonnes of sand would need to be dumped on affected stretches on a regular basis, says a marine projects expert.
Developments like Jumeirah are speeding up erosion
DUBAI // Large scale coastal developments such as the Palm Jumeirah and the World Islands have increased the rate at which Dubai's beaches are eroding, marine experts told a seminar yesterday.
To maintain the existing coastline, hundreds of tonnes of sand would need to be dumped on affected stretches on a regular basis, delegates at the Coastal Zone and Waterways Management seminar at Dubai Municipality heard.
"This rotation or erosion of the sand on the coastal beaches would be happening naturally anyway," said the marine projects expert Dr Claudia Giarrusso of Dubai Municipality's coastal zone and waterways management section. "But coastal structures like Port Rashid, the Palm and the World Islands have increased the speed of this process."
The rotation of beach sand is caused by the angle at which the Arabian Gulf current hits the coast.
The Palm and World Islands, as well as the harbours, change the angles of the current.
Data from the coastal section's monitoring of the area, which began in 2002, showed that sand was being rotated or moved to one side of the beach while the shoreline was moving further inland at the other.
"We have already carried out nourishment of beaches in Jumeirah where we have added more sand," Dr Giarrusso said. "Generally speaking, nourishment of beaches is expensive because you have to make sure you use the right kind of sand.
"However, by law, developers building property on the coast cannot simply dispose of it, [so the sand] gets handed back to the municipality for free.
"Once we make sure it is suitable, we can then add it to where it's needed."
Other options to protect the coastline include the use of rock armour and sandbags.
"Places like Al Mamzar Lagoon in Dubai need to have more maintenance because they don't get that wave action that helps to keep the beach clean and pristine," she added.
Earlier, the audience heard how Dubai Municipality had conducted detailed monitoring of the coastline and Dubai Creek using advanced radar, cameras and underwater sensors.
This had helped to create a comprehensive picture of how waves interacted with beaches and helped produce a set of guidelines for developers building near the waterfront.
"We haven't just looked at the past and present. This data has also been used to see what will happen in the future and we have also factored in all the proposed developments like the Jebel Ali Palm and Palm Deira. We can also look at the interaction of the tide and Gulf wave movement to Dubai's inland waterways," she said.