MODULE 3

• Hydrometeorological hazards


  Natural processes or phenomena that are of atmospheric, hydrologic, or oceanographic origin, which may cause the loss of lives, damage to property, social and economic disruption, or environmental degradation
• The geographic location of the Philippines accounts for the high frequency of occurrence of hydrometeorological hazards
• Hydrometeorological hazards may concur in a single event and varying intensities
• Typhoon


  A violent tropical cyclone that forms over warm waters, North of the equator in the Western Pacific Ocean, containing winds rotating counterclockwise, with a speed of 118-220 kilometers per hour. It could also develop into a super typhoon if the wind speed exceeds 220 kilometers per hour
• Impending signs of a typhoon


  • Increased ocean swell
  • Changes in clouds
  • Barometric pressure drop
  • Abrupt changes in wind speed
• Thunderstorm


  A small-scale storm accompanied by lightning and thunder, lasting about 30 minutes to an hour and may cover an area as small as 5 kilometers in diameter, bringing about other hazards such as strong winds and heavy rainfall
• Impending signs of a thunderstorm

  • System of cumulonimbus clouds
  • The sky turns dark
  • Lightning and thunder
  • Gusts of wind and change in wind direction
• Storm surge


  A rapid rise of seawater above normal sea level on the coast, generated by strong winds brought about by typhoons and thunderstorms
• Flood


  When land areas which are normally not covered with water are being submerged, often after heavy and continuous rainfall
• Flashflood


  A flood characterized by a raging current that occurs when the water level rises due to heavy rainfall, lasting from a few minutes to a few hours only
• Impending signs of a flashflood


  • Weather forecasts typhoon or thunderstorm
  • Water collecting in puddles and rapidly rising water
  • Muddy water
  • Roaring sound from upstream
  • Floating debris in water
• Hydrometeorological hazard map


  A guide that highlights areas that are vulnerable to potential hazards like storm surge, typhoon, and flood, to identify the areas that are prone to or affected these hydrometeorological hazards
• Hydrometeorological hazard maps can help prevent serious damage and deaths
• PAGASA


  The National Meteorological and Hydrological Services of the Philippines, authorized in providing the warning for the public safety of the people
• Barograph


  A barometer that continuously reads and records atmospheric pressure. It helps forecasters track changes in pressure to predict weather patterns, such as approaching storms or changes in air masses.
• Thermograph


  An instrument that measures and records air temperature continuously. Meteorologists use thermographs to monitor temperature trends over time, aiding in weather forecasting.
• Ceiling light projector


  An instrument projecting a light beam to the clouds. This aids in determining cloud height and coverage, crucial for aviation and weather monitoring at airports.
• Clinometer


  An instrument used to determine the height of the cloud base by measuring the distance from the cloud base to the ground. Pilots and meteorologists use clinometers to assess cloud ceiling for safe flying conditions.
• Ceiling balloon


  A balloon filled with hydrogen or other lighter-than-air gas used to determine cloud base height. By tracking the balloon's ascent into the clouds, meteorologists can estimate cloud height and stability.
• Theodolite


  An instrument for determining wind speed and direction. Attached to a hydrogen-filled pilot balloon, it floats at different heights, providing wind data crucial for weather forecasting and aviation.
• Radiosonde


  An instrument attached to a balloon used to measure atmospheric temperature, pressure, and humidity. It transmits data to ground receivers, aiding in weather forecasting and research.
• Wind finding radar


  Measures wind speed and direction using radar echoes. By analyzing radar data from balloons, meteorologists can track wind patterns in different layers of the atmosphere.
• Weather Surveillance Radar


  Detects and monitors the movement of typhoons and cloud masses within a 400-kilometer range. It provides critical data for tracking and forecasting severe weather events.
• Doppler Radar


  Calculates precipitation motion, estimates precipitation type, and reveals storm structure. Doppler radar helps forecasters identify severe weather conditions and issue timely warnings.
• Weather Satellite


  Provides a comprehensive view of weather disturbances and relays data from remote weather stations. Weather satellites play a vital role in global weather monitoring and forecasting.
• Flood


  A situation where land areas not typically covered by water become submerged, often due to heavy and continuous rainfall
• Flood


  • Heavy rainfall may cause temporary overflow from bodies of water or adjacent lands, leading to flooding that can last for days or even weeks
• Flashflood


  A type of flood characterized by a rapid and raging current, usually caused by heavy rainfall and lasting from a few minutes to a few hours
• Flashflood


  • Flashfloods commonly occur along rivers, mountain canyons, coastlines, creeks, and urban areas, posing a sudden and intense threat to communities
• Impending signs of a flood


  Indications that a flood may occur soon, often resembling the signs of approaching typhoons or thunderstorms
• Impending signs of a flood

  • Signs include heavy rainfall, overflowing water from manholes, and prolonged water accumulation on saturated ground, signaling an imminent flood
• Impending signs of a flashflood


  Warning signals indicating the potential occurrence of a flashflood, typically associated with heavy rainfall and specific environmental cues
• Impending signs of a flashflood


  • Signs include weather forecasts of typhoons or thunderstorms, rapidly rising water levels in puddles, muddy water indicating disturbance, roaring sounds from upstream, and floating debris in water bodies
• Weather forecasts of typhoon or thunderstorm


  Predictions indicating the likelihood of intense and prolonged rainfall, which can contribute to flashfloods
• Weather forecasts of typhoon or thunderstorm

  • Meteorological warnings of typhoons or thunderstorms serve as valuable alerts for potential flashflood events, prompting communities to take precautionary measures
• Water collecting in puddles and rapidly rising water


  Observable signs of saturated ground and impending flooding, characterized by the accumulation of water in low-lying areas and swift increases in water levels
• Water collecting in puddles and rapidly rising water

  • Puddles filling up quickly and water levels rising rapidly suggest that the ground is unable to absorb more water, increasing the risk of flashfloods in the surrounding areas
• Muddy water


  Water that has been disturbed and mixed with dirt or sediment, often indicating recent flooding or the potential for flashfloods
• Muddy water


  • Calm water bodies turning muddy suggest that sediments have been stirred up, possibly due to heavy rainfall or the onset of flooding, serving as a warning sign for communities downstream
• Roaring sound from upstream

  Audible signals of a rapidly moving current carrying debris and obstacles downstream, indicating the potential for flashfloods