Hydrometeorological Hazards

• Hydrometeorological hazards

  Natural hazards and disasters that include typhoons, earthquakes, floods, volcanic eruptions, landslides, and fires
• The Philippines is located in the Southeast Asia and is considered very vulnerable to natural hazards and disasters
• Pacific Ring of Fire


  • Circular arm of active volcanoes around the Pacific Ocean basin, where most of the volcanoes in the Philippines are part of
  • Continental plate activities around this area result in volcanic eruptions and tsunamis in the country
• Hydrometeorological


  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
• Hydrometeorological hazards


  • Typhoon
  • Thunderstorm
  • Flood
  • Flashflood
  • Storm Surge
  • El Niño
  • La Niña
• Hydrometeorological conditions lead to other hazards such as landslides, fires, plagues, epidemics and in transport and dispersal of toxic substances and volcanic eruption material
• Tropical cyclone


  An intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain
• PAGASA stated that weather forecast is a scientific estimate of future weather condition, wherein a weather condition is a state of the atmosphere at a given time expressed in terms of the most significant variables
• How is a weather forecast made?

  1. Observation

  2. Collection and transmission of weather data

  3. Plotting of weather data

  4. Analysis of weather maps, satellite and radar imageries and other data

  5. Formulation of the forecast
• Thunderstorm


  A powerful, short-lived weather disturbance, almost always associated with lightning, thunder, dense clouds, heavy rain or hail, and fast, roaring winds
• Thunderstorm formation


  1. Cumulus stage

  2. Mature stage

  3. Dissipating stage
• Flood


  A high-water stage in which water overflows its natural or artificial banks onto normally dry land, such as a river inundating its floodplain
• Types of floods


  • Inland flooding
  • Flash floods
  • River flooding
  • Coastal flooding
  • Urban flooding
• Storm surge


  The irregular sea-level rise during a tropical cyclone or "bagyo" where powerful winds force the ocean water over the coastal low-lying areas, which can lead to flooding
• El Niño


  A periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific
• La Niña


  Periods of below-average sea surface temperatures across the east-central Equatorial Pacific
• El Niño and La Niña


  Opposite results of ENSO (El Niño Southern Oscillation), the same phenomenon
• El Niño effects health such as diseases related to water scarcity or shortage, red tide blooms, and disorders associated with high temperatures
• La Niña effects health through diseases related to contaminated water due to flooding, diseases related to wading in floodwaters, diseases brought by mosquitoes, and accidents and injuries
• Natural hazard


  A natural process or event potentially damaging that result in loss of life or injury, loss of property, socio-economic destruction or environmental degradation
• Climate- and weather-related hazards

  The direct and indirect effects of observed changes in the frequencies and occurrences of extreme weather/climate events
• Natural hazards include typhoons and droughts, as well as earthquakes, volcanic eruptions and tsunamis, while deforestation, mining and climate change are man-made hazards
• Hazard maps highlight areas that are affected and/or vulnerable to a particular hazard and help prevent serious damage and deaths
• Rainfall distribution throughout the Philippines varies from one region to another, depending upon the direction of the
• Effects of observed changes in the frequencies and occurrences of extreme weather/climate events

  • Tropical cyclones
  • Droughts
  • El Niño and La Niña events
• Hydro-Meteorological Hazard Maps


  Maps that highlight areas that are affected and/or vulnerable to a particular hazard and help prevent serious damage and deaths
• Natural Hazard


  An extreme event that occurs naturally and causes harm to humans and things that we care about
• Types of hazards


  • Natural hazards
  • Anthropogenic hazards
• Climate and weather-related hazards, such as typhoons and droughts, as well as earthquakes, volcanic eruptions and tsunamis, are natural hazards while deforestation, mining and climate change is called man-made hazards
• Rainfall distribution in the Philippines


  Varies from one region to another, depending upon the direction of the winds and the location of mountain systems
• PAGASA publishes regularly updated color-coded satellite images generated from Himawari-8 that visualizes rain distribution in the Philippines
• Provinces in the Philippines highly at risk to tropical depressions, tropical storms, typhoons and super typhoons

  • Cagayan
  • Albay
  • Ifugao
  • Sorsogon
  • Kalinga
  • Ilocos Sur
  • Ilocos Norte
  • Camarines Norte
  • Mountain Province
  • Camarines Sur
  • Northern Samar
  • Catanduanes
  • Apayao
  • Pampanga
  • La Union
  • Nueva Ecija
  • Pangasinan
  • Masbate
  • Tarlac
  • Western Samar
• Philippine Radar Network


  PAGASA operates 10 weather radar stations all over the Philippines in analyzing rainfall from thunderstorms or typhoons
• Rain gauge


  A tipping bucket type that collects the rain and sends electrical signals to the receiver when it has a certain amount of precipitation
• Doppler Weather Radar


  An instrument that sends out and reflects electromagnetic signals, detecting clouds and telling the amount of rain they bring with higher resolution
• Doppler radars are located at Aparri, Baguio, Baler, Subic, Tagaytay, Virac, Gulian, Cebu, Hinatuan and Tampakan
• Flood Hazard Map


  A tool that determines flood zone areas due to different hazards such as storm, surge waves, sea level
• The NOAH Nationwide Operational Assessment website displays the PAGASA radar data, rainfall measurements of rain gauges of DOST, and has flood hazard maps in the Philippines
• El Niño


  A significant increase in ocean temperature that occurs at irregular intervals ranging from 2-7 years
• La Niña


  The cooling of surface ocean waters, a counterpart to El Niño