Typhoons:
An annual average of
30 typhoons occur in the north-western pacific
ocean of which 20 occur in Philippines alone
causing immense damage to life and property.
The typhoons occur mainly between July and November.
Strom Surges:
The irregular coastlines
and the numerous typhoons makes Philippines
vulnerable to storm surges. High tides coinciding
with a storm intensifies the surge. Factors
contributing to the height of storm surges are
a concave coastline that prevents the rising
water from moving laterally, a fast moving storm
that does not allow time for the water to spread
and shallow coastal waters. Environmental degradations
such as destruction of mangroves, coral reefs
and other forms of natural breakwater, siltation
of river deltas bays, and shore-line reclamation
also increases the storm surge hazard.
Volcanoes:
Philippines has more
than 200 volcanoes distributed along five volcanic
belts. Of these at least 17 are considered active.
The 5 most active and destructive are Mayon,
Taal, Hibok-Hibok, Bulusan and Canlaon.
Earthquakes:
Philippines lies between
two of the world's major tectonic plates, the
Pacific and Eurasian plates, The first moving
north-west is pushing the Philippines sea plates
at a rate of about 7 cm a year. The oceanic
parts of the second are being reduced along
the western side of Luzon and Mindanao at the
rate of 3 cm a year.
Eight major and several
minor earthquake generators have been identified
in the Philippines archipelago. Between 1589
and 1983, there were 63 earthquakes which caused
major destruction.
Tsunamis:
Tsunamis have affected
Philippines coastal areas up to more than 4
meters above sea level. The coastal areas of
Mindanao facing the Celebes Sea are particularly
vulnerable. From 1603 to 1975, earthquakes generated
27 tsunamis which affected coastal towns.
Landslides
The area around Baguio
in Northern Luzon with an elevation of 1460
m is prone to landslides but other parts of
Luzon and the rest of the archipelago are also
vulnerable. Excessive rainfall frequently leads
to landslides.
Droughts:
Droughts are not common
in the Philippines. The most recent drought
occurred in 1989 and resulted in damaging rice
crops of about 326 million covering 31,587 hectares
of rain-fed and irrigated lands.
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