FLOODS, FOOD MANAGEMENT, CYCLONES AND EARTHQUAKES
FLOODS: Whenever the magnitude of water flow exceeds the carrying capacity of the channel within its banks the excess of water overflows on the surroundings causes floods.
Causes of floods:
- Heavy rain, rainfall during cyclone causes floods
- Sudden snow melt also raises the quantity of water in streams and causes flood
- Sudden and excess release of impounded water behind dams
- Clearing of forests for agriculture has also increased severity of floods.
- Encroachment of flood ways should be banned.
- Building walls prevent spilling out the flood water over flood plains.
- Diverting excess water through channels or canals to areas like lake, rivers
- Where water is not sufficient.
- Optical and microwave data from IRS is also used for flood management.
- Flood forecasts and flood warning are also given by the central water commission.
CYCLONES: It is a meteorological process, intense depressions forming over the open oceans and moving towards the land.
Cyclone is measured by Saffir-Simpson scale.
- The damage depends on the intensity of cyclone the damage to human life, crops, roads, transport, could be heavy.
- Cyclone occurrence slows down the developmental activities of the area.
Classification of cyclones based on their speed.
- Satellite images are used by meteorological departments for forecasting the weather conditions which reveal the strength and intensity of the storm.
- Radar system is used to detect the cyclone and is being used for cyclone warning.
Cyclone in Orissa – 1999
- Two cyclones in Orissa occurred on 18th and 29th October 1999.In the coastal area of Orissa, a powerful cyclone storm hit with a wind velocity of about 260 km/hr. nearly 14-30 districts of Orissa were in severe damage.
- It has been reported that nearly 15 millions of people were affected and 90-95% of the crop yield was affected. About 11,500 local schools have been damaged.
The movement of earthy materials like coherent rock, mud, soil and debris from higher to lower region to gravitational pull is called landslides.
- Movement of heavy vehicles on the unstable sloppy regions.
- Earthquake, shocks, vibrations and cyclone.