natural disaster means disaster which occur among us naturally.
at times natural disasters like floods,earthquakes,tsunami etc...are very destructive. many might lose their lives.many might lose their house and other properties...for example: japan is a country where usually natural disasters occur most commonly . after a natural disaster probably health medics come for rescue to give food and other necessary requirements . natural disasters can happen any moment without any prediction.
Some other points are]
Natural Disasters.
• The natural disasters are caused by the natural process of earthquake or by human beings.
• Natural disasters are in numbers like, floods, earthquakes, volcanic eruption and many more.
• The result of these disasters is beyond imagination. 
• Results in loss of human lives and other things.
• So one must predict these loses before they actually happened.
olay thnx
okay i meant