Natural disasters connected with water
A natural disaster is a major adverse event
resulting from natural processes of the Earth;
examples include floods, volcan...
Natural disasters include
 Storms
 floods
 tsunami
 heavy rainfall
Storm
Meteorological phenomenon occurring over areas
of the seas and oceans in the form of strong,
gusty wind not less tha...
Flood
Flooding may occur as an overflow of water from water bodies, such as a river or lake,
in which the water overtops o...
Tsunami
a series of waves in a body of water caused by the displacement of a large volume
of water, generally in an ocean ...
Heavy rain
It is liquid water in the form of droplets that have
condensed from atmospheric water vapor and then
precipitat...
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Natural disasters Group3
Natural disasters Group3
Natural disasters Group3
Natural disasters Group3
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Natural disasters Group3

Published on: Mar 3, 2016
Published in: Education      
Source: www.slideshare.net


Transcripts - Natural disasters Group3

  • 1. Natural disasters connected with water
  • 2. A natural disaster is a major adverse event resulting from natural processes of the Earth; examples include floods, volcanic eruptions, earthquakes, tsunamis, and other geologic processes. A natural disaster can cause loss of life or property damage.
  • 3. Natural disasters include  Storms  floods  tsunami  heavy rainfall
  • 4. Storm Meteorological phenomenon occurring over areas of the seas and oceans in the form of strong, gusty wind not less than 8 ° on the Beaufort scale. Stormy weather is usually accompanied by high water waves. Often there are also some nasty showers of rain which limit the visibility.
  • 5. Flood Flooding may occur as an overflow of water from water bodies, such as a river or lake, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries, or it may occur due to an accumulation of rainwater on saturated ground in an areal flood. Types of floods:  Areal (rainfall-related) Floods can happen on flat or low-lying areas when the ground is saturated and water either cannot run off or cannot run off quickly enough to stop accumulating.  Riverine - river flows may rise to flood levels at different rates, from a few minutes to several weeks, depending on the type of river and the source of the increased flow.  Estuarine and coastal - flooding in estuaries is commonly caused by a combination of sea tidal surges caused by winds and low barometric pressure, and they may be exacerbated by high upstream river flow.
  • 6. Tsunami a series of waves in a body of water caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. There are three types of tsunamis:  Local - the epicentre is close to the coast, and the time of the wave arrival is estimated to half an hour,  Regional - waves could threaten greater coastal areas. The time of arrival of the wave is estimated to 5 hours since the start,  trans-regional (Pacific) - can cover many areas on both sides of the Pacific. Time that the wave needs to reach the area ranges from few to several hours depending on the epicentre.
  • 7. Heavy rain It is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Raindrops impact at their terminal velocity, which is greater for larger drops due to their larger mass to drag ratio. At sea level and without wind, 0.5 mm drizzle impacts at 2 m/s or 7.2 km/h, while large 5 mm drops impact at around 9 m/s or 32 km/h. In certain conditions precipitation may fall from a cloud but then evaporates or sublimes before reaching the ground. This is termed virga and is more often seen in hot and dry climates.
  • 8. Thank you for watching. Group3