Warnings to evacuate blasted from loudspeakers strung to palm trees and mosques as thousands of volunteers armed with megaphones, whistles and bicycles delivered coastal communities in Bangladesh the bad news - a cyclone was on its way.

To date nearly 3.5 million people have been affected by Cyclone Aila, a category one storm, that tore across Bangladesh last week, killing 179 people, washing away hundreds of thousands of homes, ravaging crops and damaging roads.

Despite the destruction, the deaths caused by Aila were a fraction of the toll brought about by earlier storms.

Just two years ago, Cyclone Sidr killed 3,500 people - far fewer than in 1991 when a cyclone claimed more than 138,000 lives. But neither disaster came close to a 1970 cyclone which left half a million people dead.

Bangladesh's success was cited by U.N. Secretary-General Ban Ki-moon, who made the point that Myanmar had no such arrangements in place when Cyclone Nargis struck in 2008. The weaker storm that struck former Burma, also a densely populated low-lying delta, was responsible for more than 40 times the number of deaths recorded after Sidr.

As aid workers scrambled to provide water purification tablets and dried food including rice and lentils to survivors of Aila, many credited - among other factors - an early warning system honed over the past decade for preventing a greater loss of life.

"I think people now realise the early warning system should be taken seriously," said Babar Kabir, who is in charge of Bangladesh aid group BRAC's disaster and climate change programme. "We are now able to get the message across that a national calamity is looming," he told AlertNet.

HITCHES

The nature of the storm was a key element which kept the death toll from Aila relatively low. The cyclone unleashed winds of up to 100 kph (60 mph), while Sidr whipped up winds of more than 250 kph.

Oxfam's Bangladesh country director Heather Blackwell said Aila did not cause as much wind damage as Sidr and the tidal surge was slower.

"This was more of a slower onset and also the cyclone hit during the daytime whereas Sidr struck at midnight."

Within 20 minutes of the meteorological office issuing its warning, more than 40,000 Red Cross volunteers were ready to deploy to villages and raise the alarm. Warnings were also broadcast on radio and television sending hundreds of thousands of residents to cyclone shelters.

But the system did not operate without some hitches.

Aid workers said in a few cases the storm was flagged as a level three in terms of danger, less serious than it actually was. In some of the outlying areas, the nearest shelters were 30 kms away from villagers' homes. The warning system did not reach other areas that had previously been unaffected by cyclones but were caught by this one.

"There were some issues with the early warning system. Some people didn't take notice of it because they thought it would hit elsewhere," Oxfam's Blackwell said.

CLIMATE CHANGE

With the immediate danger gone, efforts are now focused on dealing with the aftermath of cyclone Aila. Water levels are still high, houses remain submerged, drinking water has been contaminated and there is a growing risk of disease. Conditions have been compounded by the onset of the rainy season.

"People's suffering will continue for three to four months," said Fazlul Wahab, director of the Bangladesh Red Crescent's cyclone preparedness programme.

Looking to the future, several relief workers said the authorities need to double the number of cyclone-resistant shelters, repair the existing ones and do more to maintain embankments and improve drainage systems.

Coastal populations may benefit from the construction of elevated buildings. Salt-tolerant varieties or rice, flood and drought resilient seeds, and fast-growing crops that are harvested before monsoon season could help farmers.

But even with all those measures, the outlook is challenging.

Scientists predict the pattern of cyclones in the region will get worse with global warming, making tropical storms more frequent and more intense.

Situated at the edge of the Bay of Bengal, low-lying Bangladesh's location and geography makes it particularly vulnerable to the effects of climate change. As much as 18 percent of Bangladesh's landmass could disappear in coming decades as sea levels rise, according to World Bank estimates.

The question is whether any country can adequately prepare for that kind of disaster.

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