1) A natural disaster is defined as a natural hazard that causes significant financial and human losses through its impact on the environment. Examples include floods, earthquakes, tsunamis, and epidemics. 2) Natural disasters occur when natural hazards intersect with vulnerabilities in human systems. Major causes are seismic activity, soil erosion, and the greenhouse effect. 3) Natural disasters can be categorized as either hydrometeorological, involving atmospheric/hydrological phenomena like floods and storms, or geological, involving earthquakes, tsunamis and landslides.

1. sweet n sour proudly presents:Natural disaster

2. Question time!When strong hurricane hits in an uninhabited area in Africa ,is it by any chance considered as a natural disaster?Answer : NO! relax people ,that is merely just a natural hazard (:

3. So what is nature disaster? It is when natural hazard .(e.g. floods, volcanic eruptions, earthquakes, tsunamis, avalanches etc. ) affects the environment ,leading to financial and human losses.Epidemics caused by bacteria or viruses are considered natural disasters. Ex : swine flu .

4. What causes nature disaster?disasters occur when hazards meet vulnerability.The root causes of many natural disasters are mainly:soil erosionseismic activity andgreen house effect

5. Causes Seismic Activity:Seismic activity is the most common cause of Tsunamis. During an earthquake, the sea floor becomes deformed, forcing a displacement of water.

6. Soil erosion :Soil is naturally removed by the action of water or wind, Leading to landslides.Green house effect : greenhouse gases(CO2 , CFC etc.) make the Earth warmer by trapping the heat energy in the atmosphere ,causing icebergs to melt. More lands will be flooded as the sea level increases.

7. Two categories of natural disasters(1)Hydrometeorological Hazards which are natural processes or phenomena of atmospheric, hydrological or oceanographic nature. (These include flood, debris and mudflows, tropical cyclones, storm surges, wind, rain and other severe storms.)

8. 2) Geological Hazards are natural phenomena that include processes of endogenous origin or tectonic or exogenous origin, such as mass movements.( These include earthquakes, tsunamis, volcanic activity and landslides etc .)

9. Volcano A volcano is an opening, or rupture in a planet's surface or crust, which allows hot magma, ash and gases to escape from below the surface.effects: Volcanic ashesblastLavaGas

10. Tsunami Tsunami :tsunamis are some of the most devastating natural disasters known to man.effects :Destruction of buildingsFinancial lossesDeath Spread of disease

11. Hurricaneis a storm system characterized by a large low-pressure center and numerous thunderstormsthat produce strong winds and heavy rain. effectsSpread of diseaseDestruction of buildingsFinancial lossesDeath

12. Ten deadliest natural disasterAFTER 19201.JAPAN,1923 A third of Tokyo is destroyed and much of Yokohama in an 8.3 earthquake which between 140,000 and 200,000 people. 2.CHINA , 1931 Flood on the Changjiang River took at least 145,000 people (other estimates go over a million, but we have not confirmed that). 3.CHINA , 1935 Yellow River flood "caused 27 counties inundated and 3.4 million victims". how much is the actual figure of victims , is still not confirmed.

13. 4.CHILE , 1939 28000 people were killed from 8.3 earthquake . 5.CHINA ,1942 - 1943 A drought in the Henan province took more than a million people 's life. 6.WORLD WIDE , 1957 At least a hundred thousand peple died from Asian flu.

14. 7.AFRICA , 1981 - 1984 Rivers and lakes dried up from the drought that had incredible impact on twenty African nations. During one season about 20,000 were starving to death EACH MONTH. 150 million were facing starvation . 8.NORTH KOREA , 1995-1998 Over 3 millionare said to have died from famine and floods in North Korea. 9.12 SOUTH ASIAN NATIONS , 2004-2005 Earthquake of 9.0 and the resulting tsunami creates one of the world's worst disasters. It does major damage to: Indonesia, India, Sri Lanka, Thailand, Malaysia, Myanmar, the Maldives, Somalia, Tanzania, Seychelles, Bangladesh, and Andaman. Deaths: Between 235,000 and 285,000.

15. 10.HAITI , 2010 Earthquake - still counting.Most estimates now exceed 100,000 dead.

16. How to prevent nature disaster?There IS no way to prevent natural disasters.they HAPPEN. Earthquakes, for instance, The best prevention we can do about global warming is to use our natural resources carefully and judiciously, build our homes and other structures the best we can, to withstand as much as possible, and stop being so arrogant as to think we have more power than NATURE. And do recycling !SAVE OUR MOTHER EARTH

17. Links http://en.wikipedia.orghttp://en.wikipedia.org/wiki/Hurricanehttp://library.thinkquest.org/17457/volcanoes/effects.php

18. T.Q