Hydrometerological Hazards (DRRR)

Hydrometeorological Hazards

• are dangers associated with the natural processes of phenomena involved in the transfer of water and energy between the land surface and lower atmosphere. Among the hazards associated with these are typhoons, thunderstorms, flash floods, floods, storm surges, tornadoes, El Niño and La Niña.

cyclone

• an intense low pressure system which is characterized by strong spiral winds towards the center, called the “Eye” in a counter-clockwise flow.

Hurricane

• in the Atlantic Ocean or the eastern Pacific Oceans

Typhoons

• in the western North Pacific and Philippines

Cyclone

•  in the Indian Ocean and South Pacific Ocean

Tropical Depression

• up to 61 kph

Tropical Storm

• 62 to 88 kph

Severe tropical storm

• 89 to 117 kph

Typhoon

• 118 to 220 kph

Super Typhoon

• exceeding 220 kph

Public Storm Signal No. 1

• Winds of 30-60 kph are expected

Public Storm Signal No. 2

• Winds greater than 60 kph and up to 100 kph may expected in at least 24 hours

Public Storm Signal No. 3 

• Winds greater than 100 kph-185kph may expected in at least 18 hours

Public Storm Signal No. 4

• Very strong winds of more than 185kph but less than 220 kph may expected in at least 12 hours

Public Storm Signal No. 5 

• Maximum sustained winds of more than 220 kph may be experienced within 12 hours

Tropical Cyclone Wind Signal #1

•       WINDS: 30-60 kph may be expected in at least 36 hr

SEA CONDITIONS (Open Sea)

Wave Height: 1.25-4.0 meters

DAMAGE TO STRUCTURE:

•       Very light or no damage to high risk structures,

•       Light to medium and low risk structures

•       Slight damage to some houses of very light materials or makeshift structures in exposed communities.

DAMAGE TO VEGETATION:

•       Some banana plants are tilted, a few downed and leaves are generally damaged

•       Twigs of small trees may be broken.

•       Rice crops, however, may suffer significant damage when it is in its flowering stage.

Tropical Cyclone Wind Signal #2

WINDS: 61-120 kph may be expected in at least 24 hr

SEA CONDITIONS (Open Sea)

Wave Height:4.1-14.0 m

Storm surge possible at coastal areas.

DAMAGE TO STRUCTURE:

•       Light to Moderate damage to high risk structures;

•       Very light to light damage to medium-risk structures;

•       No damage to very light damage to low risk structures

•       Unshielded, old dilapidated schoolhouses, makeshift shanties, and other structures of light materials are partially damaged or unroofed.

•       Some old galvanized iron (G.I.) roofs may be peeled or blown off.

•       Some wooden, old electric posts are tilted or downed.

•       Some damage to poorly constructed signs/billboards.

DAMAGE TO VEGETATION:

•       Most banana plants, a few mango trees, ipil-ipil and similar trees are downed or broken.

•       Some coconut trees may be tilted with few others broken.

•       Rice and corn may be adversely affected.

•       Considerable damage to shrubbery and trees with some heavy-foliaged trees blown down.

Tropical Cyclone Wind Signal #3

WINDS: 121-170 kph may be expected in at least 18 hr

SEA CONDITIONS (Open Sea)

Wave Height: > 14.0 meters

Storm surge possible at coastal.

DAMAGE TO STRUCTURE:

•       Heavy damage to high–risk structures;

•       Moderate damage to medium-risk structures;

•       Light damage to low-risk structures

•       Increasing damage to old, dilapidated residential structures and houses of light materials (up to 50% in a community)

•       Houses of medium strength materials (old, timber or mixed timber-CHB structures, usually with G.I. roofings), some warehouses or bodega-type structures are unroofed

DAMAGE TO VEGETATION: Almost all banana plants are downed, some big trees (acacia, mango, etc.) are broken or uprooted,

•       Dwarf-type or hybrid coconut trees are tilted or downed

•       Considerable damage to shrubbery and trees with heavy foliage blown off; some large trees blown down.

Tropical Cyclone Wind Signal #4

WINDS: 171-220 kph may be expected in at least 12 hr

SEA CONDITIONS (Open Sea)

Wave Height: more than 14.0 meters

Storm surge 2-3m possible at coastal areas.

DAMAGE TO STRUCTURE:

•       Very heavy damage to high –risk structures.

•       Heavy damage to medium risk structures;

•       Moderate damage to low-risk structures

•       Considerable damage to structures of light materials (up to 75% are totally and partially destroyed); complete roof structure failures.

•       Many houses of medium-built materials are unroofed, some with collapsed walls; extensive damage to doors and windows

•       A few houses of first-class materials are partially damaged

•       All signs/billboards are blown down.

DAMAGE TO VEGETATION: There is almost total damage to banana plantation,

•       Most mango trees, ipil-ipil and similar types of large trees are downed or broken.

•       Coconut plantation may suffer extensive damage.

•       Rice and corn plantation may suffer severe losses.

Tropical Cyclone Wind Signal #5

WINDS: > 220 kph may be expected in at least 12 hr

A Super Typhoon will affect the locality.

SEA CONDITIONS (Open Sea)

Wave Height: more than 14.0 m

Storm surge more than 3 meters possible at coastal areas

DAMAGE TO STRUCTURE:

•       Widespread damage to high-risk structures

•       Very heavy damage to medium-risk structures

•       Heavy damage to low-risk structures;

•       Almost total damage to structures of light in highly exposed coastal areas.

•       Complete roof failure on many residences and industrial buildings. Severe and extensive window and door damage

•       Most residential and institutional buildings of mixed construction may be severely damaged.

•       Electrical power distribution and communication services severely disrupted.

•       All signs/billboards blown

DAMAGE TO VEGETATION:

•        Total damage to banana plantation

•       Most tall trees are broken, uprooted or defoliated;

•       Coconut trees are stooped, broken or uprooted.

•       Few plants and trees survived

 

Flood

• is the inundation of land areas which are not normally covered by water. A flood is usually caused by a temporary rise or the overflowing of a river, stream, or other water course, inundating adjacent lands or flood-plains.

Flash flood

• it is a rapid flow of water on saturated soil or dry soil. These are usually caused by extensive rainfall can also be induced by man-made structures such as water overflows from a dam.

Storm Surges

• it is an abnormal rise in coastal waters due to a massive force from the sea or from the above sea level. It can be caused by strong typhoon. It can also be disastrous and can also aggravate by the occurrence of high tide.

La Niña

• is associated with extreme climatic variability such as devastating rains, winds, anomalies in rainfall, temperature and tropical cyclone activities.

El Niño

• refers to the large-scale warming of the ocean and atmosphere across the central and east-central Equatorial Pacific.