Hydrometeorological Hazards

• Hydrometeorological Hazards

  • These are processes or phenomena of atmospheric hydrological or oceanographic nature
  • Hydrometeorological conditions also can be a factor in other hazards such as landslides, wild fires, locust plagues, epidemics, and volcanic eruptions
• Typhoons

  • low pressure area or tropical cyclone that is large and violent.
  • rotates counterclockwise with warm air rising above the warm water of the Western Pacific Ocean
• there are two theories that support the formation of typhoons:

  1. convective theory which states that the mass of air becomes convectively unstable and moist compared to its surrounding air.
  2. frontal or counter-current theory which indicates that many tropical cyclones form along the front between the trade winds and the equatorial air in the doldrums. 
• PAGASA has its classification of tropical cyclones

  • Tropical Depression - 61 kph or less
  • Tropical Storm - 62 - 88 kph.
  • Severe Tropical Storm - 89 - 117 kph
  • Typhoon 118 - 220 kph
  • Super Typhoon - more than 220 kph
• Public Storm Warning Signals

  Signal no. 1 - 30 - 60 kph in at least 36 hrsSignal no. 2 - 61 - 120 kph in at least 24 hrsSignal no. 3 - 121 - 170 kph in at least 18 hrsSignal no. 4 - 185 - 220 kph in at least 12 hrs

  Signal no. 5 - 220+ kph
• A typhoon has four major life stages:

  1. Formative Stage
  2. Immature Stage
  3. Mature Stage
  4. Decaying Stage
• Automatic Weather Station have built in weather instruments with electronic sensors for measuring surface level, air temperature, pressure solar radiation, rainfall amount, wind speed built-ins; the station have integrated data banks for storage data for later retrieval.
• Rain Gauge also known as udometer, pluviometer, ombrometer, and hyetometer. to measure the amount of liquid precipitation. It is to catch rainfall through a tipping bucket mechanism that registers water content to be sent at PAGASA.
• A "Weather Surveillance Radar" is the long range type which detects and tracks typhoons and cloud masses at a distance of 400 kilometers or less. This radar has a rotating antenna disk preferably mounted on top of a building free from any physical

  obstruction.
• Automated Weather Observation helps pilots to make critical decisions by providing real-time information and reports on airport weather condition
• Upper Air Observation is used to record the vertical profile of the atmosphere, information that is essential to create a global interview.
• Flood is an abnormal progressive rise in the water level of the stream that may result in the overflowing by the water of the normal confines of the stream
• Flash flood have a rapid nature of flowing and covering areas that have a little to no absorption capability.
• Storm surges are described as an outflow of water into coastal areas
• Each sources of fire has its designated type of fire extinguisher:

  
  

  Class A - AFF Foam, Water, Dry Powder

  Class B - AFF Foam, CO2, Dry Powder

  Class C - Dry Powder

  Class D - L2 and M28 Powder

  Class E - CO2, Dry Powder

  Class F - Wet Chemical
• there are three ways to combat fire:

  1. starvation - limitting the fuel
  2. cooling - limitting heat
  3. smothering - limitting oxygen