DRRR

• Hydrometeorological hazards


  Processes or phenomena 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
• The troposphere has the highest pressure
• Pressure varies from day to day at the Earth's surface - the bottom of the atmosphere
• Air pressure


  Dependent on temperature
• What happens to the molecules of air as it gets heated?

  They become agitated and has the tendency to leave the area
• Convection current


  Areas where the air is warmed often have lower pressure because the warm air rises
• ITCZ (Intertropical Convergence Zone)


  Area where trade winds from the Northern hemisphere and southern hemisphere bring tropical air masses together
• ITCZ is important because northerly and southerly winds carry moisture that is responsible for the formation of clouds
• These air masses are warm and humid, resulting in the formation of convective clouds and subsequent heavy precipitation during most of the year
• Different hydrometeorological hazards


  • Typhoon
  • Thunderstorm
  • Flood
  • Storm Surge
  • El niño
  • La Niña
  • Rainfall-induced landslide
  • Tornado
• Typhoon


  Severe weather disturbance characterized by strong winds and heavy rains, which revolve around a central low-pressure area
• Favorable conditions in the formation of a typhoon

  • Warm ocean waters (26 C and above) throughout a depth of about 150ft
  • An atmosphere that cools fast enough with height
  • Relatively moist air near the mid-level of the troposphere (4,900m)
  • Generally, a minimum distance of at least 480km from the equator
  • A pre-existing near-surface disturbance
  • Low values (37km/h) of vertical wind share between the surface and the upper troposphere
• Formation of typhoon


  1. Warm water (26 C) rises (water vapor) creating a low-pressure area at the surface of the ocean

  2. Water vapor cools and condenses, forming cumulonimbus clouds

  3. Cumulonimbus clouds form into long spiraling cloud bands

  4. Coriolis effect causes incoming winds to swirl around the central are of low pressure

  5. Drier air from higher altitudes is slowly drawn down the center, causing a calm "eye"

  6. Typhoon-force winds circle around the eye

  7. The storm system is pushed along its track by trade winds
• Hurricane vs. Typhoon vs. Cyclone are just the same, they only differ in name
• Saffir-Simpson Hurricane Intensity Scale

  • Tropical Depression (61km/h or less)
  • Tropical Storm (62km/h - 88km/h)
  • STS (Severe Tropical Storm) (89 km/h - 117 km/h)
  • Typhoon (118km/h - 184km/h)
  • Super Typhoon (185km/h and above)
• Three main parts of a typhoon - Typhoon structure

  • Eye
  • Eye wall
  • Rain bands
• Coriolis effect


  The deflection of an object moving on or near the surface caused by the planet's spin
• In the northern hemisphere, the spiraling motion of the typhoon is counterclockwise, while in the southern hemisphere is clockwise
• Typhoon classification


  • Red warning (more than 30mm rain)
  • Orange warning (15-30mm intense rain)
  • Yellow warning (7.5 - 15mm heavy rain)
• Mitigating the destructive effects of typhoon

  1. Determine areas prone to typhoon-related disasters

  2. Implementing legislation involving land use planning, zoning, and building standards

  3. Weather forecasting and monitoring

  4. Effective public typhoon warning systems
• PAGASA


  Philippine Atmospheric, Geophysical and Astronomical Services Administration - sub agency of DOST, provides protection against natural calamities and to ensure the safety, well-being and economic security of all the people, and for the promotion of national progress by undertaking scientific and technological services in meteorology, hydrology, climatology, astronomy, and other geophysical sciences
• RSMC Tokyo - Typhoon Center


  Monitors and provides information on tropical cyclones in the Western North Pacific and South China Sea, including present and forecast positions as well as the movement and intensity of tropical cyclones
• WMO (World Meteorological Organization)

  Maintains rotating lists of names that are appropriate for each Tropical Cyclone basin. If a cyclone is particularly deadly or costly, then its name is retired and replaced by another one
• What to do before a typhoon?

  1. Tune in to local news for government announcements and warnings

  2. Know when and where the cyclone is going to hit

  3. Know the important emergency hotlines in your community

  4. Identify credible people or other sources of important information regarding the typhoon

  5. Familiarize yourself with the Early Warning System and Evacuation plan of your local government

  6. Make a household evacuation plan and give particular tasks to each member of the family

  7. Check our surroundings if there are things to be repaired

  8. If you are in a danger zone, go to a safe evacuation center

  9. Follow instructions given by the DRR personnel
• What to do during a typhoon?

  1. Stay tuned-in to the radio or television for latest news and updates

  2. Stay Alert and Be prepared

  3. Stay inside the house

  4. Wear Warm Clothes

  5. Save your Batteries so you can use it for emergency situations

  6. If you are already in danger, call for rescue
• What to do after a typhoon?

  1. Stay tuned-in to the radio and TV for Latest Updates

  2. Check your family if they're okay

  3. Observe your surroundings if there are fallen trees, wrecked cars on the road, fallen electric posts and live wires

  4. If there are damages in you household, do repairs

  5. If there is an injury, seek for medical help
• Thunderstorm


  A violent, transient type of weather disturbance associated with thousands of meters tall cumulonimbus clouds which usually involves lighting and thunder, strong winds, intense rainfall and occasional tornadoes and hail
• Thunderstorms happen due to uneven distribution of heat in the air and on land
• Thunderstorms often occur in the equational region at any time but mostly in the afternoon or evening during summer
• Floods


  Presence of excessive water on a supposedly dry land, caused by the abnormal rise of water level in rivers, coastal areas and other bodies of water, caused by continuous rains or poor drainage
• Causes of floods


  • Natural causes: High Tide, Prolonged Rainfall, Storm Surge
  • Manmade causes: Deforestation, Failure of Sea Walls and Dams, Informal Setlers and dumping of garbage, increased urbanization and rapid coastal development (reclamation)
• Types of floods


  • Riverine/River Floods
  • Estuarine and Coastal Flooding
  • Urban Flooding
  • Catastrophic Flooding
  • Flash Flooding
• Destructive effects of flooding

  • Primary effects: Loss of Life, Damage to properties and Infrastructure
  • Secondary effects: Power loss, Food Shortage, Domestic/ Potable Water loss or shortage, Risk of Acquiring water-borne diseases, Difficulty of Mobilization due to flooded and impassable roads
  • Tertiary effects: Economic hardships in the local/national level due to Unemployement, Destruction of production and businesses, Decline in Tourism, Destruction of Wildlife habitat
• Mitigation of flood hazards

  1. Government preparation of Flood Hazard Maps

  2. Flood Forecasting using Moduling Software

  3. Building of Flood Control Systems such as Seawalls, Dams, Levees, and Diversion Canals

  4. Establishment of Rainfall Advisories
• What to do before a flood?

  1. Keep tuning-in to the news in TV and radio for update

  2. Be familiar with the frequency of floods in your area

  3. Know where the flood warning system such as flood markers in you area are

  4. Know the evacuation plan in your area

  5. Prepare your survival kit

  6. Fully charge your phones, keep these loaded, and put them inside a zip lock plastic bag

  7. Prepare for emergency lights

  8. Prepare the family or friends by assigning tasks

  9. Keep all important documents in water proof bags
• What to do during a flood?

  1. Keep Calm, be alert and keep away from steep areas prone to landslides

  2. Stay updated on news and public announcements

  3. Don't attempt to swim across flowing streams and flooded areas

  4. Watch out for snakes and other wild animals in the flood

  5. Drink only boiled
• everyone should be alert for possible evacuation
• Torrential Rains
• Serious Flooding is expected in low lying areas
• Evacuation is Imminent