Hydrometeorological hazard is a process or phenomenon of atmospheric, hydrological or oceanographic nature that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage.

2. •Hydrometeorological hazards are processes
or phenomena of atmospheric, hydrological
or oceanographic nature
•may cause loss of life, injury or other health
impacts, property damages, loss of
livelihoods and services, social and
economic disruptions, or even environmental
damages
Hydrometeorological Hazards...

3. Hydrometeorological hazards include:
-TROPICAL CYCLONES
(TYPHOONS/HURRICANES)
-THUNDERSTORMS
-HAILSTORMS
-TORNADOES
-COLD SPELLS
-HEAVY SNOWFALL
-FLOODS/FLASH
FLOODS
-DROUGHT
-HEAT WAVES
-STORM
SURGES
-
AVALANCHES
-BLIZZARDS
Hydrometeorological hazards...

4. Hydrometeorological conditions also can be
a factor in other hazards such as landslides,
wild fires, locust plagues, epidemics, and
volcanic eruptions.
Hydrometeorological hazards...

5. The following are the most common
Hydrometeorological hazards as defined by the
National Oceanic and Atmospheric
Administration (NOAA):
CYCLONE
TYPHOON
FLOOD
STORM
SURGE
TORNADO
FLASH FLOOD
THUNDERSTO
RM
EL NIÑO and LA
NIÑA
PotentialHydrometeorological
Hazards

7. A cyclone is an intense low pressure system
which is characterized by strong spiral winds
towards the center, called the “Eye” in a
counter-clockwise flow in the northern hemisphere.
Hazards due to tropical cyclones are strong winds
with heavy rainfall that can cause widespread
flooding/flash floods, storm surges, landslides and
mudflows.

8. Classification of Cyclone:
Tropical Depression–maximum winds from
35 kilometers per hour (kph) to 63 kph
Tropical Storm–maximum winds from 64 kph
to 118 kph
Typhoon–maximum winds exceeding
118 kph

10. A typhoon is a large, powerful and violent
tropical cyclone. It is a low pressure area rotating
counter-clockwise and containing rising warm air
that forms over warm water in the Western Pacific
Ocean. Less powerful tropical cyclones are called
Tropical Depression and Tropical Storms.

11. A typhoon is called a hurricane in the Atlantic
Ocean, a cyclone in Indian Ocean and wily- wily in
Australia. Typhoons can inflict terrible damage due
to thunderstorms, violent winds, torrential rain,
floods, landslides, large and very big waves
associated with storm surges.

13. A thunderstorm is a weather condition that
produces lightning and thunder, heavy rainfall from
cumulonimbus clouds and possibly a tornado. It is
a violent local disturbance accompanied by
lighting, thunder and heavy rain and often by
strong gust of wind, and sometimes by hail.

14. The typical thunderstorm caused by
convection occurs when the sun’s warmth has
heated a large body of moist air near the ground.
This air rises and called by expansion.
The cooling condenses the water vapor
present in the air, forming a cumulus cloud.

16. •a tornado is described as a violent rotating
column of air extending from thunderstorm to the
ground
• tornadoes come in many sizes
•are typically in the form of a visible
condensation-funnel which is narrow and
touches the earth
• is often encircled by a cloud of debris

17. •have a wide- range of colors depending on the
environment
•typically, may appear nearly transparent and
invisible until dust and debris are picked up
•develop from severe thunderstorms in warm,
unstable air along and ahead of cold fronts

19. A flash flood is a rapid flooding of
geomorphic low-lying areas like washes, rivers,
dry lakes and basins.
Common causes of flash flood:
 heavy rain with a severe thunderstorm
 tropical storm
 melt water from ice
 snow flowing over ice sheets
or snowfields
 hurricane

20. •flash floods may occur after the collapse of a
natural ice or debris dam, or a human structure
such as man-made dam
•flash Floods are distinguished from regular
floods by a timescale of less than six hours

22. 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
over- flowing of a river, stream, or other water
course, inundating adjacent lands or flood-
plains.

23. •temporary rise of lakes, oceans or reservoirs
and/or other enclosed bodies of water
•heavy and prolonged rainfall associated with
tropical cyclones, monsoons, inter-tropical
convergence zones or active low pressure areas
•debris jam causes a river or stream to
overflow and flood the surrounding area.

24. Floods are basically HYDROLOGICAL PHENOMENA
caused by storm surges, and tsunami
along coastal areas
Two key elements are rainfall intensity and
duration. Intensity is the rate of rainfall, and
duration is how long the rain lasts.

26. Storm surge is the rise of the seawater
above normal sea level over the coast, generated
by the action of weather elements such as
cyclonic wind and atmospheric pressure. Sea level
is raised and driven towards the coast. Where the
depth is shallow and the slope of the sea bed is
gradual, the natural flow of water is delayed by the
effect of friction on the sea bed.

27. As more water moves from the sea to the coast
excess water piles up on the shore line. This
pilling up of water makes a large volume of
water which might eventually flow into hinterland
some distance from the coast.
Depending upon the shape of the coastline and
the slope of the sea bed, storm surge can sweep
across large portions of coastal areas.

29. El Niño and La Niña are complex weather
patterns resulting from variations in ocean
temperature in the equatorial pacific. These two
phenomena are opposite phases of what is known
as the ElNiño-Southern Oscillation (ENSO)
cycle.

30. The ENSOcycle is a scientific term that
describes the fluctuations in temperature
between the ocean and the atmosphere in the
East-central Equatorial Pacific (approximately
between the International Date Line and 120
degrees West).

31. LaNiña is sometimes referred to as the cold
phase of ENSO and ElNiño as the warm phase of
ENSO. These deviations from normal surface
temperatures can have large-scale impacts not
only on ocean processes, but also on global
weather and climate.

32. ElNiño and LaNiña episodes typically last
nine to 12 months, but some prolonged events
may last years. While their frequency can be quite
irregular, El Niño and La Niña events occur on
average every two to seven years.
Typically, El Niño occurs more frequently than
La Niña.

34. The general sequence of events that
could occur during the development of a
Category 2 typhoon/hurricane (wind speed 96-
110 mph) approaching a coastal area: (Herald
Tribune, 2011)

35. 96hoursbefore landfall:
At first there aren’t any apparent signs
of storm. The barometer is steady, winds are
light and variable, and fair-weather cumulus
clouds appear.

36. 72hoursbefore landfall:
Little has changed, except that the swell
on the ocean surface has increased to about
six feet and the waves come in every nine
seconds. This means that the storm, far over
the horizon, is approaching.

37. 48hoursbeforelandfall:
The sky is now clear of clouds, the
barometer is steady, and the wind is almost
calm. The swell is now about nine feet and
coming in every eight seconds.

38. 36hoursbefore landfall:
The first signs of the storm appear. The
barometer is falling slightly, the wind is around
11 mph, and the ocean swell is about 13 feet
and coming in seven seconds apart.

39. On the horizon, a large mass of white cirrus
clouds appear. As veil of clouds approaches, it
covers more of the horizon. A hurricane watch
is issued, and areas with long evacuation
times are given the order to begin.

40. 30hoursbefore landfall:
The sky is covered by a high overcast.
The barometer is falling at .1 millibar per hour;
winds pick up to about 23 mph. The ocean
swell, coming in five seconds apart, is
beginning to be obscured by wind- driven
waves and small whitecaps begin to appear on
the ocean surface.

42. SATELLITE-is the most advance technology
used in monitoring a cyclone or
typhoon. It can visualize exactly in real
time the formation and the path of a
cyclone.

43. Doppler RADAR
is an acronym for Radio Detection and
Ranging. Radar detection devices emit and
receive radio waves to determine the distance
from the source to the object by measuring the
time if it takes for the echo of the wave to
return.

44. Specifically, weather radar measures the
direction and the speed of moving objects,
such as precipitation, and has a capacity to
measure the velocity of the particles in order to
determine the rate of which the particles are
falling.

45. HOW DOES A
DOPPLER
RADAR WORK?

47. Preparedness
and Mitigation

48. The following preparedness and mitigation
strategies are adopted from the Department of
Education’s Disaster Risk Reduction Resource
Manual issued on 2008:

49. Preparedness (Whattodo before):
• Establish and maintain coordination with
Barangay Disaster Coordinating Councils
(BDCC) and personnel.
• Ensure that house can withstand heavy
rain and strong winds.

50. • Learn more about typhoon and other
weather disturbances, their signs and
warnings, effects and dangers and how to
protect house and other properties.
• Learn something relevant to mitigation
and preparedness for tropical cyclones.
• Participateactively to school’s disaster
response-drill or simulation.

51. Response (What to do during):
•Monitor through radio or other reliable
sources the latest official report of PAGASA on
the typhoon.
•When house is no longer safe, evacuate
immediately to safer place

52. • Stay indoors and away from windows.
•Keep an open line of communication. with
relatives that are not affected to keep them
posted.
•Ensure that members of the family will remain
calm by keeping them informed of
the latest developments.

53. Rehabilitation (What to do after):
•Help in attending the victims immediately. For
minor cuts and wounds apply first aid.
•In case of major cuts and wounds, seek
necessary medical assistance at disaster
station or hospital.

54. •Help in checking the house for damages and
losses. Note damages that require immediate
repair, e.g. electrical connections and water
supply.
•Coordinate with Barangay officials and
LGU’s for assistance.

55. Preparedness (Whattodo before):
Develop a Family Preparedness Plan
Incase of severe thunderstorm–specific
planning should include the following:

56. •Learn more about your area’s severe
thunderstorm risk.
•Discuss how you would know if a
thunderstorm may produce a tornado.
•Discuss how to be warned of an
approaching thunderstorm.

57. •Recommend trimming and removal of
dead or rotting trees that could fall and may
cause damage or injury.
•Secure outdoor objects that could be
blown away and cause damage.
•Secure house doors and windows both
from the inside and outside.

58. •Learn how to estimate the distance of the
thunderclouds by computing the difference in
time(second) between seeing the flash of
lightning and hearing the claps of thunder. (1
second = 1000 ft.).

59. Response (What to do during):
•Learn to do the lightning safety position
and stay away from structures, trees,
towers, fences, telephone lines, or power
lines if out in the open.
•Carefully watch out for falling debris and
flash floods.

60. •Stay calm throughout the occurrence of
thunderstorm.
• Postpone all outdoor activities.
•Avoid plumbing and bathroom fixtures
that are good conductors of electricity.

61. •Unplug or turn off all appliances and other
electrical items such as computers.
•Turn off air conditioner and television and
stay off the phone until the storm is over. Use
a battery operated radio for gaining
information.

62. •Choose and move to a ‘safe place’ in
your house (if there is any) where members of
the family can gather together during a
thunderstorm preferably on lowest floor of
your house. Where there are no windows,
skylights, or glass doors, which could be
broken by strong winds or hail, causing
damage or injury.

65. “Lightning safety experts have
invented a ‘lightning safety position’ that is
very important to know if you are caught in a
thunderstorm and you can’t find a
shelter.
FOLLOWTHELIGHTNINGSAFETY
POSITIONfor:
 It makes you a smaller target

66. With your heels together,if lightning hits the
ground, it goes through the closest foot, up to
your heel and then transfers to the other foot
and goes back to the ground again. Ifyou
don’t put your feet together, lightning
could go through your heart and kill you. You
put your hands over your ears to protect
themfrom thunder.”
(Lightning Safety Experts)

67. Preparedness (Whattodo before):
•Develop a preparedness plan for the whole
family.
•Have periodic drills with the members of the
family.
•Inspect pre-designated areas to ensure the
best protection.

68. •Keep an open line communication with
other members of the family.
•Listen to radio and television for
information.
•Store flashlights and back-up batteries to
receive warnings reponse.

69. Response (Whattodo during):
•Move to pre-designated area or an interior
room on the lowest floor and get under a sturdy
piece of furniture.
• Stay away from windows.
•Lie flat in a depression if caught outside
your house/ school or any building.

70. Rehabilitation (Whattodo after):
• Attend to survivors immediately.
• Check the house for damages and losses.
•Coordinate with proper authorities for
assistance.

71. Preparedness (Whattodo before):
•Find out the frequency of occurrence of floods
in locality, especially those that affect your area.
•Know the flood warning system in your locality.
If none exists, recommend to the appropriate
authority for the creation of one.

72. •Research from previous occurrences how fast
the water floods occur in your area and how it
rises.
•If it has been raining hard for several hours, or
steadily raining several days, be alert to the
possibility of a flood. Floods happen as the
ground becomes saturated.

73. •Watch out for rapidly rising water and help
prepare the family for evacuation.
•Switch off the electricity and lock the
rooms after all have gone out.
Have a handy survival kit. It should contain
battery operated transistor radio,

74. flashlight, emergency cooking equipment,
candies, matches, and first aid kit.
•Use a radio or a portable, battery-powered radio
(or television) for updated information. Local
stations provide the best advice for your
particular situation.

75. Response (Whattodo during):
• Stay calm and keep updated with the
status of the situation and safety reminders
on what to do and where to go in case of
evacuation.
•Listen continuously to a radio, or a
portable, battery-powered radio (or
television) for updated emergency
information.

76. •Do not attempt to cross flowing streams
unless assured that the water is below knee
high level.
•Avoid areas prone to flash flooding and be
cautious of water- covered roads, bridges,
creeks and stream banks and recently flooded
areas.

77. •Do not go to swimming or boating in
swollen rivers.
• Watch out for snakes in flooded areas.
•Eat only well-cooked food and drink only
clean or preferably boiled water and throw
away all food that has come into contact with
flood water.

78. Rehabilitation (Whattodo after):
•Report broken utility lines (electricity, water,
gas, etc.) immediately to appropriate
agencies/authorities.
•Ensure that electrical appliances are checked
by a competent electrician before switching
them on.

79. • Avoid affected areas.
•Continue to listen to a radio or local television
stations and return home only when
authorities indicate it is safe to do so.
•Stay away from any building that is still
flooded.

80. Preparedness (Whattodo before):
•Know the storm surge risk zones and
identify safer grounds for relocation if
necessary.
•Ensure that everyone is familiar with the
identified escape routes of the family to
higher grounds.

81. •Stay off the beach when weather
disturbance exists.
•Help establish evacuation plans and
procedures.
•Participate in the regular conduct of drills and
exercises.

82. Response (Whattodo during):
•Immediately move to higher grounds upon
detection of signs of a probable storm
surge or upon receiving a warning that a
storm surge is eminent.
•Be alert of and stay away from steep,
high coastal areas which are prone to
landslides.

83. • Switch off power supply.
•Stay on the on the inland side away
from the potential flow of water.
•If caught in a storm surge, take hold of
large boulders or tree trunks which can
provide protection from the force of water
or debris carried by the flowing water.

84. Rehabilitation (Whattodo after):
•Do not eat fresh food that came in
contact with flood waters.
•Drinking water should be submitted to
proper authorities for testing.
•Check damage of the house to ensure that
there is no danger of collapse.

85. •Check house for electrical damage and
open live wires. Electrical fixtures should
only be switched on after making sure that
is safe to do so.
•Help clean all mud and debris
immediately.

87. The following are examples of
hydrometeorological hazard maps.

91. PROJECTNOAH by the department of
science and technology(DOST)
- a project for scientific forecasting, monitoring,
assessment and information services regarding
natural hazards
- a more accurate, integrated, and responsive
disaster prevention and mitigation system,
especially in high-risk areas throughout the
Philippines

92. Project NOAH (Nationwide Operational
Assessment of Hazards)
The project will harness
technologies and management services
for disaster risk reduction activities
offered by the DOST through PAGASA,
PHIVOLCS, and the DOST-
Advance Science and Technology
Institute (ASTI), in partnership with the
UP National Institute of Geological
Sciences and the UP College of
Engineering.

93. The Project has the following components:
1.Distributionof hydrometeorological
devices inhard-hit areas inthe Philippines
(Hydromet).A total of 600 automated rain
gauges (ARG) and 400 water level monitoring
stations (WLMS) will be installed along the
country’s 18 major river basins (RBs) by
December 2013 to provide a better picture of
the country’s surface water in relation to
flooding.

94. 2.DisasterRiskExposure Assessmentfor
Mitigation –LightDetection and Ranging
(DREAM-LIDAR)Project.The project, which is
targeted to be completed by Dec. 2013, aims to
produce more accurate flood inundation and
hazard maps in 3D for the
country’s flood-prone and major river
systems and watersheds.

95. 3.Enhancing Geohazards Mapping through
LIDAR.The project which is targeted to be
completed by December 2014, shall use
LIDAR technology and computer-assisted
analyses to identify exact areas prone to
landslides.

96. 4.Coastal Hazardsand StormSurge
Assessmentand Mitigation (CHASSAM).
CHASSAM, which is targeted to be
completed by December 2014, will generate
wave surge, wave refraction, coastal
circulation models to understand and
recommend solutions for coastal erosions.

97. 5.Flood InformationNetwork(floodNET)
Project.Targeted to be complete by
December 2013 is the flood center that will
provide timely and accurate information for
flood early warning systems. The FloodNET
Project will come up with computer models for
the critical RBs, automate the process of data
gathering, modelling and information output,
and release flood forecasts.

98. 6.Local Development of Doppler Radar
Systems(LaDDeRS).LaDDeRS seek to
develop local capacity to design, fabricate, and
parameters of sea surface such as wave,
windfield, and surface current velocity.

99. 7.Landslides SensorsDevelopment Project.
This project is a low cost, locally developed,
sensor based early monitoring and warning
system for landslides, slope failures, and
debris flow. As of May 2012, 10 sensors have
been installed in:

100. San Francisco, Surigao del Norte; Tago,
Surigao del Sur; Tublay, Buguias, and Bokod
in Benguet; Guihulngan City, Negros
Occidental; St. Bernard, Southern Leyte; and
Tubungan, Iloilo. Additional sensors are
expected to e deployed to not less than 50
sites by 2013.

101. 8.Weather hazard InformationProject
(WHIP).WHIP involves the utilization of
platforms such as television (DOSTv) and a
web portal (http://noah.dost.gov.ph), which
display real-time satellite, Doppler radar, ARG
and WLMS data to empower LGUs and
communities to prepare against extreme natural
hazards. This is complimented by activities,
such as:

102. a)conducting IEC (Information, Education, and
Communication) activities;
b)the processing and packaging of
relevant and up-to-date information for
public use.