Hydrometeorological hazards . Flashcards
are different meteorological, hydrological and climate phenomena that can pose risks to human society.
Hydrometeorological hazards
It is a natural heat engine that converts heat energy of the ocean into strong winds and waves.
It is a rotating system of clouds that originate over tropical or subtropical waters
Tropical Cyclone
Tropical Cyclone: Formation Requirements
27°C temperature for upper ocean
Air should be warm, humid, and unstable.
Storm should be far enough from the equator.
A typhoon begins with a low pressure zone that forms poorly organized thunderstorms with a relatively weak surface
tropical disturbance
As the surface wind strengthens and creates an efficient flow around and into the center of the storm, it has now become a
tropical depression.
When the surface-wind exceeds a speed of 63 km/hr,
a tropical storm
is formed when the surface-wind exceeds a speed of 119 km/hr. At this speed, none of the wind reaches the center of the storm creating a calmer and clearer area at the center.
The eye of the storm
the basis by which a tropical storm is called a hurricane, typhoon or cyclone
the eye of the storm is at a speed of 119 km/hr,
is formed in the Indian Ocean and South Pacific Ocean.
Cyclone
It is called a blank if it formed west of Pacific Ocean,
typhoon
is formed in the Atlantic and Northeast Pacific.
a hurricane
PAGASA’s Classification of Typhoons
Tropical depressions (TD)
Tropical storms (TS)
Severe tropical storms (STS)
Typhoons (TY) and
Super typhoons (STY)
have a speed of ≤ 61kph;
Tropical depressions (TD)
have a speed of 62-88 kph;
Tropical storms (TS)
have a speed of 89-117 kph;
Severe tropical storms (STS)
have a speed of 118-220 kph;
Typhoons (TY)
have a speed of >220 kph
Super typhoons (STY)
refers to an increase in the sustained winds over a short time interval.
Squall
can also be formed which is expected for about half of the storms of tropical storm (TS) intensity
Tornadoes
is both beneficial and harmful. It is essential because it is a natural irrigation for farms and automatically supplies the water needs of dams.
Rainfall caused by typhoons
abnormal rise of water due to tropical cyclones is another disastrous hazard.
Storm surge
Are tall, buoyant clouds of rising moist air which generate lightning, thunder, commonly accompanied by rains and gusty winds.
Thunderstorms
occur locally, the least destructive and only last for a short amount of time.
Air-mass thunderstorms
are a violent type created from a huge upward current of warm air.
Supercell thunderstorms
is a rotating column of wind which extends downward from the cloud and reaches the ground.
Tornado
happen when there is an overwhelming amount of water introduced.
These usually occur as a result of storms or when bodies of water overflow.
Floods
results from heavy rainfall for hours in a local area.
A flash flood
occurs when a large amount of rain falls over a large area for days or weeks
A regional flood
Human responses to flood hazards are divided into two categories
structural and nonstructural
involve the building of structures to address floods
Structural responses
include other methods that do not require the construction of structures
Nonstructural responses
The Four Phases of Disaster Reduction
Mitigation or Prevention
Preparedness
Response
Recovery
These are long-term activities undertaken prior to impact which aimed to reduce the risk of occurrence and/or effects of a disaster.
Mitigation or Prevention
Prior and during the actual disaster, activities are done immediately to protect lives and properties.
Response
These are pre-disaster activities intended to increase the effectiveness of emergency response during the disaster.
Preparedness
These are post-disaster activities undertaken in order to return affected communities to a more normal condition.
Recovery
