DISASTER

• Cyclone


  A kind of hazard that forms in the northern hemisphere due to a phenomenon characterized by a very low pressure
• Cyclone


  • Characterized by its "eye" or the spiral winds which flow counter clockwise toward its center
• Cyclone


  Produces moderate to heavy rainfalls that can result to flashfloods, mudflows, landslides, and storm surges in different areas affected by its movement
• Classifications of Tropical Cyclone


  • Tropical Depression (35kph to 65 kph)
  • Tropical Storm (64 kph to 118 kph)
  • Typhoon (exceeds 118 kph)
• Typhoon


  A severe weather disturbance characterized by strong winds and heavy rains that revolve around a central low-pressure area
• The Philippines is one of the most frequently visited countries by tropical cyclones - with a yearly average of 19 typhons entering the PAR and six to nine making landfall
• Tropical Cyclone Activity

  • Lowest in May
  • Greatly increases from July until September
  • Tapers off in November
• Typhoon Haiyan, which is the strongest typhoon on the Philippine history so far, struck in November 2013
• The country's "typhoon belt" has shifted from northern Luzon to southern Luzon and the Visayas islands
• Tropical Cyclone


  • On average, it has a total diameter of 550 km but can reach a diameter of more than 2,000 km wide
  • Its basic structure is composed of an eye, eye wall, and surrounding rain bands
  • Forms as a result of the atmosphere's natural tendency to maintain equilibrium by redistributing heat through the wind from the equatorial regions to the polar regions
• Tropical cyclones perennially affect countless casualties and indescribable damage to property in many countries making them one of the most destructive natural phenomena worldwide
• Tropical cyclones bring very strong winds, heavy rains, and can cause flooding and storm surges
• Effective forecasting and monitoring of tropical cyclones give people ample time to prepare and secure the properties and to seek refuge
• Coriolis Effect


  An effect whereby a mass moving in a rotating system experiences a force (the Coriolis force) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic
• Life of a Tropical Cyclone


  • A tropical cyclone typically has a life span of nine days and can travel more than 10,000km
  • Tropical cyclones that form in the Pacific Ocean usually tend to travel in a more west or west northwest direction, affecting the Philippines
  • Those that form in the South China Sea usually tend to travel in a more northward or northeast direction, still frequently affecting the Philippines
• PAGASA


  • The Philippine Atmospheric, Geophysical and Astronomical Services Administration is the lead agency of the government on forecasting and observing tropical cyclones using satellite and field data
  • Models are used to predict the timing and areas that might be affected by tropical cyclones
  • PAGASA releases tropical cyclone warnings in the form of public storm warning signals
• Public Storm Warning Signal #1


  • Winds: 30-60 kph may be expected in at least 36 hr
  • Wave height: 1.25-4.0 meters
• Damage to Structure and Vegetation under Public Storm Warning Signal #1


  • Very light or no damage to high risk structures
  • Light to medium and low risk structure
  • Slight damage to some houses or very light materials or makeshift structure in exposed communities
  • Some banana plants are tilted, few leaves are generally damaged
  • Twigs of small tress may be broken
  • Rice crops, however, may suffer significant damage when it is in
• Public Storm Signal #2


  • Winds: 61-120 kph may be expected in at least 24 hr
  • Wave height: 4.1 - 14.0 meters
• Damage to Structure under Public Storm Signal #2

  • 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
  • Other structures of light materials are partially damaged or unrooted
  • Some old galvanized iron roofs may be peeled or blown
  • Some wooded, old electric posts are tilted or downed
  • Some damage to poorly constructed
• Damage to Vegetation under Public Storm Signal #2


  • Most banana plants, a few mango trees, ipil-ipil and similar trees are downed or broken
  • Most 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
• Public Storm Signal #3


  • Winds: 121-170 kph may be expected at least 18 hr
  • Wave Height: 14.0 meters
  • Storm surge possible at coastal areas
• Damage to Structure under Public Storm Signal #3


  • Heavy damage to high-risk structures
  • Moderate damage to medium-risk structures
  • Light damage to low risk structures
  • Increasing damage houses of light materials
  • Houses of medium strength materials, some warehouses or bodega-type structures are unroofed
• Damage to Vegetation under Public Storm Signal #3


  • 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
• Public Storm Warning Signal #4


  • Winds: 171-220 kph may be expected in at least 12 hr
  • Wave height: 14.0 meters
  • Storm surge 2-3m possible at coastal areas
• Damage to Structure under Public Storm Warning Signal #4


  • 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
• Damage to Vegetation under Public Storm Warning Signal #4


  • 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
• Public Storm Waming Signal #5


  • Winds: greater than 220 kph may be expected in at least 12 hr
  • A super typhoon may affect the locality
  • Wave height: 14.0 meters
  • Storm surge more than 3m possible at coastal areas
• Damage to Structure under Public Storm Warning Signal #5


  • Widespread damage to high-risk structures
  • Very high 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
• Damage to Vegetation under Public Storm Warning Signal #5


  • 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