Kattumaanap Poriyaalar october 2013 | Page 36

conveyance canal and distribution network also improve the environment and do not degrade the environment where it is taken to. 4. Green Technology in development of Water Resources a) Use of Green Technology in the development of water resources can be discussed under two broad heads. viz i) Surface water ii) Ground water i) Surface water development in which water in the surface water bodies like Rivers, Lakes, Tanks, etc., are preserved, regulated and monitored for use of humanity in various sectors. ii) Identification of Ground water and monitoring their extraction. aquifers, estimating their quality and potential The methods of design and execution of the above have been developed over long years of experience and research to provide an efficient system of storage and distribution. Rules regarding the operation of the system have also been developed by field and institutional research in consultation with the field engineers who operate the system to ensure minimum loss. These methods do not pollute the source and hence can rightly be called Green Technology. However there is always scope for refinement towards minimizing loss. b. Developing secondary (recycled) sources of water i) Sea water desalination iii) Effluent treatment plants of industries. ii) Low temp desalination iv) Water recycling and reuse from waste water treatment plants. Even though there is no alternative source of water, the water already used in a process and got mixed with other substances can be got back and used for certain restricted purposes so that the demand on freshwater will be reduced to that extent. The Technology adopted in the above methods not only reduces the demand on freshwater but also prevents pollution of existing water resources and can therefore an addition to Green Technology. These however, require further and continuous research and strict monitoring. 5. Rainwater Harvesting (RWH) consists of catching water at source (Rainfall) and putting them to various uses. This method avoids loss due to various factors that are common in other methods of harnessing water. Rainwater harvesting is classified into i) Domestic RWH iii) Industrial RWH ii) Farm Land RWH iv) Storm Water treatment The above techniques are new approaches in water harvesting and reduces the demand on conventional water sources. They add to the quantum of water made available to the use of humanity without affecting the environment; infact enhancing it Repetitive and renewable, they extensively support the concept and can very well be called valuable addition to Green Technology, though they are simple in concept and construction. è † ´ ñ £ ù Š ªð £ P i) Demand and supply ò Even though the worlds water resources is renewable in the sense that water is brought to land £ from the oceans and seas by Hydrologic Cycle which is repeated several times seasonally and ÷ has a set annual pattern, the quantum of water brought by the Hydrologic cycle in the form of ˜ rainfall and snowfall in a year is limited. 6. Conservative use of Water fl;Lkhdg; nghwpahsh; 38 mf;Nlhgh; 2013