PETALING JAYA: Flood sirens are only effective if the public is aware of what the warning is for, say experts.
According to the Irrigation and Drainage Department (DID), there are 614 flood alert sirens and 197 surveillance cameras installed nationwide.
The sirens can be heard from a distance of up to two kilometres and emit two types of sounds – one an alert and the other signalling danger. These systems are also equipped with real-time monitoring telemetry.
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Director at Universiti Malaysia Kelantan’s Jeli campus Prof Dr Aweng Eh Rak said sirens are a useful tool and an effective alert system.
“But the people must be educated on what the (flood) siren sounds like so they do not confuse it with ambulances, fire departments or other emergency sirens.
“There are a places where voice alerts are used, and this is helpful to avert confusion,” he said.
Universiti Teknologi Malaysia Disaster Preparedness and Prevention Centre director Dr Khamarrul Azahari Razak said siren audibility and coverage are of utmost importance.
“During recent floods, sirens were generally audible within core settlement areas. However, heavy rainfall and strong winds, as well as the spread of houses over a wide area, affect how well the sound carries.
“The sound may be faint for households located further away, suggesting that additional sirens or complementary alert methods may be necessary,” he said.
He said that sirens had proven useful, especially when linked to upstream river monitoring data or rainfall intensity sensors.
When triggered before water reaches critical levels, it provides residents with a vital window of time to prepare.
He said the community’s understanding of siren signals strongly influences its effectiveness.
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“Residents must clearly recognise that the siren indicates a real and immediate risk.
“Past feedback shows that some residents are still unsure of what different siren tones mean or the danger level they represent,” said Khamarrul.
He added that regular community briefings and mock drills are needed to ensure everyone knows exactly how to respond.
Senior Lecturer at Universiti Malaysia Kelantan’s (UMK) Faculty of Earth Sciences Assoc Prof Dr Mohamad Faiz Mohd Amin said a study has shown that a fully functioning early warning system can reduce the impact of disasters by up to 30%.
However, it may not perform to its full potential if the community does not understand the meaning of the siren or if it is not clearly heard.
“Many residents do not hear the siren because it is obstructed by buildings, hills or even (drowned out by) the wind.
“The use of Geographic Information Systems acoustic modelling, which is a common practice in the European Union and Japan, can ensure they are installed in optimal locations,” he said.
Mohamad Faiz said sirens need to be combined with other channels, such as mobile applications, SMS broadcasts, WhatsApp alerts from the local council and the DID, radio, digital signboards and community flood wardens.
Yesterday, Deputy Prime Minister Datuk Seri Dr Ahmad Zahid Hamidi said a total of 9,800 personnel from various govern ment agencies and 7,000 operational assets had been mobilised nationwide to tackle flood disasters.
Also available, he said, were modular steel panel bridges (Bailey bridges) for use in situations where roads are cut off due to flooding.
