Chennai: The annual average rainfall for Tamil Nadu, about 945 mm, has not reduced in the last 30 years and the current deficit for fresh water is due to the failure to protect high rainfall catchment areas and high altitude terrains that serve as a home for seasonal rivers. Besides, urban development in tier one cities like Chennai, Coimbatore and Tiruchy, the failure to conserve water aquifers and river basins has added to the water crisis of the state, explain biologists and weathermen.
According to conservation scientist Dr. A. Kumaraguru, member, National Tiger Conservation Authority, the failure to understand rainfall and its role in a particular landscape has made matters worse for all of south India. Despite being blessed with rainforests en-demic to the Western Ghats, the failure to conserve fragile ecosystems is a major cause for the fresh water deficit. For instance, the Kalakad Mundan-thurai Tiger Reserve (KMTR) receives rainfall from both the monsoons and ranges from 750 mm on the eastern outer slopes to 3500 mm in the western higher reaches catering to Tirunelveli and Tuticorin districts.
Similarly, the Annamalai tiger reserve which houses Chinnakallar and Valparai rainforests receives heavy rainfall throughout the year, ranging above 4000 mm.
The average rainfall has not chan-ged in the Western Ghats that spread over Kerala, Karnataka and Tamil Nadu. Only the management of our natural resources and demand has made the southern states vulnerable to water scarcity.
Says Sai Praneeth, blogger at weather of South India, "The annual average rainfall of Tamil Nadu is 958.5 mm. Except for seven years (1995, 2000, 2001, 2002,2003,2012 and 2013), the state has received good rains in the past 20 years." There have also been cases of above normal and excess rainfall. Drought was noted in 1995 (46% below normal rainfall) and 2000 ( 28 percent below normal), otherwise TN is blessed with good rainfall, he adds.
