DRR LAS 12 STEM-11 (POTENTIAL HYDROMETEOROLOGICAL HAZARDS)

• Natural hazards such as floods, droughts, and heat waves pose threats to SOCIAL-ECOLOGICAL SYSTEMS around the world
• In most cases, floods and droughts are caused by…. 


  a COMBINATION of naturally occurring EXTREME WEATHER EVENTS and ANTHROPOGENIC activities
• What are hydrometeorological hazards??

  These are phenomenon of ATMOSPHERIC, HYDROLOGICAL, or OCEANOGRPAHIC NATURE that may cause loss of life, injury, economic disruption or environmental damage
• 7 Examples of Hydrometeorological Hazards in the Philippines

  1. Cyclone
  2. Typhoon
  3. Flood/Flashfloods
  4. Stormsurge
  5. Lightning Storms and Thunderstorms
  6. El Niño
  7. La Niña
• CYCLONE

  • an intense LOW-PRESSURE SYSTEM
  • counter-clockwise flow in the NORTHERN HEMISPHERE
• Classification of Cyclones

  1. Tropical depression- maximum wind speed from 35kph to 63kph
  2. Tropical storm- max. winds from 64-118kph
  3. Typhoons- max. winds > 118kph
• Typhoon

  • low-pressure area rotating counter clockwise
  • over warm water in the WESTERN PACIFIC OCEAN
  • identified as ocean swell
  • barometric pressure drop
  • wind speed and heavier rainfall
• Public Storm Warning Signals

  1. SIGNAL #1 - winds 35-60kph (36 hours) TROPICAL CYCLONE
  2. SIGNAL #2 - 60-100kph (24 hours) MODERATE “”
  3. SIGNAL #3 - 100-185kph (18 hours) STRONG “ “
  4. SIGNAL #4- >185kph (12 hours) VERY INTENSE TYPHOON
• Flood/Flashflood

  • inundation of land areas which are normally covered by water
  • hydrological phenomena
  • are also caused by storm surges and tsunami
  • identified by continuous storms/rains, distant thunder, muddy water that carries other debris
• Storm Surge

  • a RISE of SEA WATER above normal sea level on the coast
  • generated by the action of WEATHER ELEMENTS such as CYCLONIC WIND AND atmospheric pressure
  • CAN sweep large portions of coastal areas
• Lightning Storms and Thunderstorms

  • a weather condition that produces LIGHTNING AND THUNDER
  • heavy rainfall from CUMULONIMBUS CLOUDS and possibly a tornado
  • identified by cloud formations, darkening skies, lightning and wind
• El Niño

  • identified by HOT WEATHER, high pressure, gradual DRYING
  • flow of unusually WARM WATER along the WESTERN coast of SOUTH AMERICA
  • causes many changes in weather and other places
• La Niña

  • climate pattern that describes the COOLING of SURFACE OCEAN WATERS
  • along the TROPICAL west coast of South America
  • cold air, less temperature difference, cooler water and air, and single weaker jet stream.