Bahrain designs sea barriers to withstand possible sea level rise

Sea barriers
Soman Baby, Gulf Daily News 24 May 09;

EVERY new construction project in Bahrain will now be designed to withstand possible rises in the country's sea level, it has been revealed.

The decision is part of Bahrain's commitment to the UN Global Disaster Risk Reduction programme, said UN resident co-ordinator and UN Development Programme (UNDP) resident representative Sayed Aqa.

"Bahrain is the first Arab country to meet all the requirements for implementing the Hyogo Framework for Action, which is the globally approved disaster risk reduction initiative," he told the GDN.

"As Bahrain is one of the countries where 75 per cent of the urban inhabitants are exposed to rising sea levels, it has taken a major initiative to face disasters by setting up a National Disaster Management Committee (NDMC).

"Because of the climate change, it is estimated that sea levels could rise by up to one metre and in some areas up to six metres by the end of the century.

"The government has decided to protect all new developments against a possible sea level rise."

Public Works Affairs Under-Secretary Nayef Al Kalali said all construction projects in Bahrain now have to comply with the new Dredging and Land Reclamation Technical Manual.

It states that reclaimed land must be at a certain height above sea level and different levels have been proposed for different areas of Bahrain, according to the strength of the wind and tidal wave attacks, he added.

The types of benefits expected from the project are:

lEnvironmental - safeguard environment sensitive areas, identify suitable areas for development and areas which are not environment sensitive which can be reclaimed.

lProtection against natural disasters - such as flooding, rising sea levels (global warming and the greenhouse effect and rising sea levels have created a need to be prepared by proposing reclamation levels which safeguard against any flooding and wave attacks).

lEconomic - the manual helps optimise the cost of dredging and reclamation projects by identifying optimum levels for reclamation.

The study by Delft Hydraulics was undertaken to determine reclamation and crest levels and its recommendations were calculated on the basis of extreme water levels which occur once every 100 years, said Mr Al Kalali.

The report also considered the impacts of tides, storm surges, barometric pressure, wind and wave set up and run up, meteorological fluctuations and climate change.

The process included investigations, statistical analyses and mathematical modelling.

Indicative wave crest level calculations were also conducted at five reclamation sites around Bahrain.

The amount of reclamation works and design parameters were then updated and imported into a Geographical Information System (GIS) and a resulting recommended reclamation level map of Bahrain was produced.

The outcome of the study provided clearance levels for the expected rise in sea water levels due to global warming.

"This is now set at 0.4 metres in 100 years and an additional safety clearance of 0.1 metre has also been added," said Mr Al Kalali.

The manual was produced with input by a Works Ministry-commissioned consortium led by Dutch consultant Deltares.

Consortium

The consortium included Delft Hydraulics, Anthony Bates Partnership Dredging and Coastal Consultants and Dredging Research Limited.

The manual provides suitable coastal engineering defence measures required for every land reclamation process and how to select the best of these systems and methods.

In 1981, the size of Bahrain was 665.3sqkm.

In 2007, it was 741.40sqkm, an increase of 76.1sqkm in 26 years.

"This is an expansion of the kingdom by 11.4 per cent and this has been from land which has been reclaimed from the sea, mainly for housing and industrial developments," said Mr Al Kalali.

"The number of islands which make up our archipelago is dynamic and as of the end of 2007 Bahrain comprised 196 islands (133 are natural islands and 63 artificial islands).

"Yet, Bahrain still experiences a shortage of land for future housing, industrial and infrastructural development.

"To address this, the government has developed a plan following an integrated approach to continue reclaiming land from the inter-tidal zone."