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