WHAT IS A STORM SURGE?
Cyclone Size
A storm surge is a localized unusual increase of sea water level A tropical cyclone with a larger diameter will form a higher surge
beyond the predicted astronomical tide level due to intense winds because the winds brought about by larger tropical cyclones push on
and atmospheric pressure of a tropical cyclone. a larger surface area of the ocean and affects this area for a longer
period of time.
WHERE DOES IT OCCUR?
Storm Forward Speed
This catastrophe commonly happens on low-lying coastal areas.
A tropical cyclone travelling with a higher velocity will produce a
The Philippines is very prone to storm surges because of its location
higher surge along an open coast while a cyclone travelling with a
near the equator in the Pacific Region, and due to its extensive
lower velocity is more efficient in producing higher and broader
coastline length.
surge.
CAUSES OF STORM SURGE
Timing
Wind Speed
When the formation of a storm surge during a tropical cyclone
A storm surge is mainly wind-driven. Storm intensity, which is related coincides with a high astronomical tide, the resulting surge is higher.
to the wind speed of a storm, has an influence on the amount of
Amplification of waves when storm surge and high tide happen at the
surge produced. The stronger the winds associated with a tropical
same time.
cyclone, the higher the storm surge formed.
WARNINGS AND SIGNALS
The Pressure Effect
PAGASA launched on June 2019 its upgraded storm surge warning
A lower atmospheric pressure results in a higher storm surge level.
system to help the public better prepare for tropical-cyclone related
Lowered atmospheric pressure and wind speed are the major
hazards.
causes of storm surge formation.
POTENTIAL DAMAGE BY A STORM SURGE
Buildings, road, bridges, piers and other infrastructure may not only Bhola Cyclone (1970)
be submerged, they can also washed away and destroyed. Deadliest storm surge on record
Cars and almost anything else in the path of the storm surge will A devastating tropical cyclone that
surely be drifted away from their original positions. struck East Pakistan and India's West
Bengal on November 3, 1970 with 3-
The life-threatening nature of storm surges is nothing to take a
minute sustained speed of 185 km/hr
chance on.
At least 500,000 people lost their lives
PEOPLE AFFECTED BY STORM SURGE
in the storm primarily as a result of the
RESIDENTS OF COASTAL AREAS - Their properties and life are storm surge that flooded much of the
threatened from damaging storm surges. low-lying islands of the Ganges Delta.
FISHERMAN - They cannot catch fishes due to high water levels and Cyclone Nargis (1970)
the fish nets will be destroyed. Deadliest storm surge in the 21st
Century
FARMERS - Their crops will be destroyed and worn out by high
levels of water The cyclone made landfall in
Myanmar on Friday, 2 May 2008,
DOES A REPORTED STORM SURGE AFFECT PEOPLE AT ALL sending a storm surge 40 kilometres
TIME? up the densely populated Irrawaddy
Reported storm surges that occurs on inhabited places affects delta, causing catastrophic destruction
people at all time. and at least 138,373 fatalities
MOST DAMAGING EVENTS Cyclone Mahina (1899)
Highest storm tide
Typhoon Yolanda “Haiyan” (2013) recorded
One of the strongest and deadliest
typhoons Mahina struck Bathurst Bay, Cape
York Peninsula,
On November 28, 2013, Typhoon Queensland, on 4 March 1899,
Yolanda made landfall initially on and its winds and enormous storm
Guiuan, Eastern Samar with 10- surge combined to kill more than
minute sustained speed of 230 km/hr 300 people.
According to calculations made, the
storm surge at Tacloban must have reached over 5 metres. Tides
and wave heights were not included in the calculations.
Hurricane Katrina (2005) Storm surge barriers are gate-like, hard engineering structures
One of the greatest storm surge in installed in front of tidal inlets, rivers, and estuaries which are closed
US before impending extreme water level increase, like storm surges.
Strucked on August 29, 2005 and WETLAND PROTECTION
produced a maximum storm surge of
People can make efforts to protect nearby wetlands because the
more than 28 ft (8 metres) in southern
sediments and vegetation found in swamps, estuaries, and mud flats
Mississippi, with a storm surge height
can actually dampen the destructive force of storm surges.
of 27.8 ft (8.5 m) in Pass Christian.
Preparation
HOW CAN IT BE CONSIDERED A HAZARD?
Keep listening to official warnings of storm surges issued by
According to PAGASA, 0.5-meter high storm surge can be
PAGASA.
considered a hazard because it poses a threat to people that live on
coastal areas affected. Find the nearest safe high ground where you can evacuate.
WHY DO PEOPLE LIVE IN AREAS AFFECTED BY STORM When evacuating, bring with you only what is important and
SURGE? essential.
Their source of living are on or near the bodies of water. Your planned route of evacuation should avoid any conduits of water
as flashfloods can occur.
HOW COULD PEOPLE PREVENT DISASTER WHEN STORM
SURGE STRIKES?
CONSTRUCTION OF STORM SURGE BARRIER
