Professor T. Shivaji Rao of Gitam University in Visakhapatnam is passionate about cloud seeding for increasing rainfall.
WATER SCARCITY CAN BE AVOIDED BY CLOUD SEEDING THAT INCREASES ANNUAL RAINFALL BY ABOUT 25%
Due to the heat from the Sun the water in the rivers, lakes and Oceans becomes water vapour. As this hot moist air rises into the sky the temperature gets reduced at 7oC per km height in the sky. and the water vapour condenses over smoke and dust particles to form cloud droplets upto 20 microns[micron is a millionth of a meter] A million cloud droplets must join together to form into a raindrop of 1mm size to fall over the earth as rainfall or snowfall
RAIN FORMATION: If a warm cloud does not contain sufficient number of large size water drops or hygroscopic particles the cloud cannot give 10% to 20% of its moisture as rainfall. In cold clouds whose tops attain freezing level in the sky, insufficient number of ice-nuclei prevents the clouds from giving normal precipitation .
HOW DOES CLOUD SEEDING HELP?: If warm clouds have to give more rain we have to inject into them chemicals like hygroscopic common salt or Calcium powder into such clouds We have to inject Silver Iodide particles into cold clouds which extends into the freezing zone for about 15km into the sky. So injection of chemicals into the clouds causes additional rainfall upto 25 %
CHINA IS WORLD LEADER IN CLOUD SEEDING: In China 37,000 technicians are employed to produce additional annual rainfall of 60 billion cubic meters or 1750 Thousand Million Cubic ft which is equivalent to the annual river flow in KrishnaRiver in South India. The cost benefit ratio is estimated at 1:15. Cloud seeding is done in more than 40 countries during the last 50 years. .India must take up cloud seeding to fight the recurring droughts and also to resolve the interstate water disputes in the Cauvery, Krishna and other rivers and also to fight the damaging impacts of global warming. Although several doubts have been raised by scientists in USA and other countries Chinese Meteorologists have researched and establish that cloud seeding is not only highly scientific but is also a proven technology, if done on scientific lines.
WHY IS CLOUD SEEDING UNAVOIDABLE?: In modern times urbanization, industrialization and deforestation are increasing the environmental pollution and global warming which are preventing the clouds from giving the normal rainfall and consequently drinking water supply and agriculture production, hydro power generation and employment opportunities are adversely effected. Hence cloud seeding must be undertaken to supply more water to correct the above disadvantages.
Director, Centre for Environmental Studies, Gitam University,
Phone: 0891 - 2504902, 2738211