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Natural disaster


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Natural disaster

  1. 2. Natural disaster A natural disaster is a destruction caused by nature to the humanity . Examples: Earthquakes Tsunamis Cyclones Landslides Forest fires
  2. 3. Effects of Deforestation <ul><li>Landslides became more frequent because of deforestation. </li></ul><ul><li>Deforestation has affected rain. </li></ul><ul><li>Less rain causes droughts and famine </li></ul><ul><li>Too much rain causes floods. </li></ul>
  3. 4. <ul><li>Metereologists , weather scientists, keep a careful watch on temperature, rainfall and humidity conditions all over the country. </li></ul><ul><li>Daily report given in the newspaper shows the maximum and minimum temperatures and the rainfall in many major cities of India. </li></ul><ul><li>Most newspapers carry INSAT-1B picture showing cloud patterns over India on the previous day </li></ul>Weather reports in newspapers
  4. 5. INSAT-1B picture
  5. 6. Cyclones <ul><li>They are powerful, spinning storms which form over warm tropical waters and reach wind speeds over 120 km/hr . </li></ul><ul><li>When it moves and crosses over land, it brings with it heavy rain and high velocity winds. </li></ul>
  6. 7. Effects of cyclones <ul><li>Torrential rain that can cause flooding </li></ul><ul><li>Extremely strong winds that carry debris that can be lethal </li></ul><ul><li>Damage buildings and property </li></ul><ul><li>Destroy crops </li></ul><ul><li>Capsize boats at sea </li></ul><ul><li>Deaths due to drowning </li></ul><ul><li>Infrastructure destroyed </li></ul>
  7. 8. Effects of cyclones
  8. 9. Droughts and famine <ul><li>Lack of rain causes droughts . </li></ul><ul><li>Drought can cause crops to wither and dry up, it also affects the farming communities badly. </li></ul><ul><li>It can lead to a severe shortage of food called Famine . </li></ul>
  9. 10. Effects of Droughts <ul><li>Hunger, thirst and famine </li></ul><ul><li>Wildfires </li></ul><ul><li>Diseases </li></ul><ul><li>Social conflicts </li></ul><ul><li>Migration and relocation </li></ul>
  10. 11. Effects of Droughts Wildfire
  11. 12. Precautions to be taken <ul><li>Construct reservoirs in advance to store water for emergency. </li></ul><ul><li>Check deforestation and plant trees. </li></ul><ul><li>Rainwater harvesting. </li></ul><ul><li>Urge people not to waste water or food. </li></ul><ul><li>Educate farmers periodically to avoid over cropping and overgrazing . </li></ul>
  12. 13. Layers of Earth
  13. 14. Earthquakes <ul><li>The sudden shaking of ground is known as Earthquake . </li></ul><ul><li>It can be quite strong and can cause much damage. </li></ul><ul><li>To understand how an Earthquake is caused, we must first understand what lies inside the Earth </li></ul>
  14. 15. Causes for Earthquake <ul><li>The lithosphere or the crust literally floats on the mantle. </li></ul><ul><li>Earthquakes occur along the fault lines where the tectonic plates meet. </li></ul><ul><li>Convection currents in the magma makes the tectonic plates to move constantly. </li></ul><ul><li>Some plates slide past one another and form strains on the rocks. </li></ul><ul><li>An Earthquake results when the strains buildup and causes the rocks to break. </li></ul>
  15. 16. Tectonic Plates
  16. 17. Effects of Earthquakes <ul><li>Avalanches </li></ul><ul><li>Tsunami </li></ul><ul><li>Death </li></ul><ul><li>Buildings collapse </li></ul><ul><li>Breaking of gas lines, roads and bridges </li></ul><ul><li>Flooding </li></ul><ul><li>Fire </li></ul>
  17. 18. Effects of Earthquakes
  18. 19. Detection of Earthquakes <ul><li>Seismologists, measure the strength of an Earthquake by estimating the amount of energy released at the focus. </li></ul><ul><li>The focus is the point of origin of an Earthquake. </li></ul><ul><li>Seismic waves are detected, recorded and measured by instruments called seismographs . </li></ul>Seismograph
  19. 20. Precautions to be taken <ul><li>Identify a safe place at home, school and office – under a desk or against an inside wall . </li></ul><ul><li>Practice three vital steps of drop, cover and hold on. </li></ul><ul><li>If you are outside stay away from buildings, trees and electric poles. </li></ul><ul><li>Learn first aid and to operate a fire extinguisher. </li></ul>
  20. 21. Earthquake Fact on Himalayas The Himalayas were formed before about 200 millions of years ago, when India collided with Asia for the first time. The collision made the two lands to rise and form Himalayas.