Natural disasters are drastic changes that may cause damage to the shape of the land or to the lives of people and other living things. Many changes may happen deep inside the earth and on its surface. These natural disasters can be classifed as:
Earthquakes: Earthquakes are powerful manifestations of sudden releases of strain energy accumulated within the crust and propagated as seismic waves. The most disastrous natural calamity for mankind is an earth quake. So the need to understand and study the phenomenon of earthquake is very important.
Volcanic eruptions: A Volcano is a hill that is formed by molten lava. Volcanoes can be active or inactive. In active volcanoes magma melts due to heat or any other reason, than it takes more space and tends to come out of the hill. Volcanic eruptions can be extremely dangerous as they can result in a heavy ash fall, mudslides, eruption of various gases like sulphur-di-oxide that can prove fatal.
Landslides: Landslides are mass movement of rocks and debris that usually follow a cyclone, volcano or earthquake. These are common natural disasters in hilly areas.
Drought: A drought is the lack of rain for a long time.There are three types of droughts, Meteorological drought is when the actual rainfall is much less than the climatologically mean of the area.
Hydrological drought results from the depletion of surface water and,
Agricultural drought resulting from depletion of soil moisture.
Cyclone: A Cyclone is a fierce storm with storm winds that spin around it in a giant circle. Cyclones are seen in intense low pressure areas with pressure increasing outwards. Cyclones can be hazardous as cyclones are normally associated with strong winds. During cyclone an abnormal rise of sea level inundates low lying areas of coastal regions drowning human beings and lives- stock, eroding beaches and embankments, destroying vegetation and reducing soil fertility.
Forest fire: Fires can burn out of control in areas of forest or bush land. Fires are caused by lightning, sparks of electricity or reckless people. Apart from loss of human lives, natural disasters cause severe damage to both ecology and economy of a region. Though it may not be possible to control nature and to stop the development of natural phenomena but the efforts can be made to avoid disasters and improve their effects on human lives, infrastructure and property.
Space technology has made significant contribution in predicting natural disasters. Forecast of certain natural disasters likes earthquake, volcanic eruption and flood is still at developmental level. Hopefully future developments may help in refining existing approaches for prediction of such natural disasters and their management