Floods, droughts and famines are also natural calamities like earthquakes and volcanoes which man has to face. However, there is a case of floods, drought and famines he is able to control them, diminish the danger and at times even completely eliminate them as in the case of famines.
Floods are caused by three factors – 1. Cloud burst, 2. Monsoon depression and 3. Tropical cyclones. Of late, deforestation and soil erosion are also causing floods. India depends for its rain on both the monsoons, south-western and north-eastern. The south-west monsoons start in May and continue up to the end of September. The north-east monsoon starts in November and continues right up to the middle of January.
Heavy rain caused an account of the three seasons referred to, result in the overflow of rivers. The major rivers that cause floods in India are the Ganges and its tributaries, the Brahmaputra and the Godavari. The problem has become severe now on account of deforestation and depositing of soils in the beds.
When heavy rains fall in catchments areas, they lead to soil erosion and the fertile alluvial soil is washed off and deposited in the river beds. This, at time, helps some countries. For example, the deposit left by Nile has helped Egypt. But it is not so in case of all rivers either in India or in china. When floods occur they inundate low lying areas by the sides of the rivers and caused huge loss of life, crops and other properties.
Cloud-bursts means highly concentrated rainfall in a particular area, which is far above normal. This usually happens in places like Rajasthan in India. Moreover, depressions occur both in the Bay of Bengal and in the Arabian Sea. They are more frequent in the Bay of Bengal. Atleast twenty depressions occur every year between May and September in different parts of the Bay of Bengal. These depressions results in heavy rains in coastal areas of Andgra Pradesh, Orissa, Bengal, Bihar and utter Pradesh. The depressions caused in the Arabian sea help rains in Gujarat, Rajasthan and the South Himalayan parts.
However, with the construction of dams on almost all rivers, intensity of floods has been checked. The other rivers which are overflowing now are likely to be harnessed soon. Floods may not be a serious problem to us. The heavy deforestation is causing alarm. It has to be checked. Dams and canals linking all rivers in the county is a necessity. For example, a canal linking Ganges with Cauvery would solve this problem.
The cyclones are more dangerous as they are combined with high speed winds. A cyclonic storm with the forming of an eye may take any direction. The high speed winds which start a cyclone cause more damage than the accompanying floods.
The Orissa super-cyclone of 1999 was one of the worst cyclones to have hit India. It claimed more than 10,000 lives and shattered the lives of millions. Those who survived this cyclone felt that the dead were more fortunate, revealing the intensity of suffering of the survivors.
Droughts are caused on account of scanty rainfall. This happens mostly on account of vagaries of monsoons which are not under our control. They also usually occur in rain shadow areas like Anantapur and Mahaboobmnagar districts of Andhra Pradesh and in some district in Maharashtra and Rajasthan. They also can be overcome by adopting scientific methods of conservation of soil and by constructing check dams, water level could be raised. This would help to avoid droughts.
Recently research has developed better methods of agriculture even in drought prone areas. The ICRISAT (International Crops Research Institute for Semi-Arid Tropics) established at Hyderabad is extending immense service in this direction. Hence we can confidently hope that drought no longer may threaten us.
Nazture3 has its own ways. We should respect and safeguard the environment without polluting it and destroying it. Man with all his intelligence is able to safeguard him self against floods, but he is not able to produce, increase or reduce rainfall which causes the floods. Hence nature still remains our master.