Drought -- National Drought Mitigation Center

 

Title

Assessment of Recent Droughts in Tamil Nadu

Document Type

Article

Date of this Version

October 1995

Comments

Published in Drought Network News October 1995. Published by the International Drought Information Center and the National Drought Mitigation Center, School of Natural Resources, University of Nebraska – Lincoln.

Tamil Nadu, a coastal state in south India, is prone to droughts. The climate of the state ranges from dry subhumid to semiarid. The state has three distinct rainfall climates: (1) advancing monsoon period (from June to September), with strong southwest winds; (2) northeast monsoon (from October to December), with dominant northeast winds; and (3) dry season (from January to May). The normal annual rainfall of the state is about 945 mm.

Tamil Nadu is classified into seven agroclimatic zones: northeast, northwest, west, southern, high rainfall, high altitude hilly, and Cauvery Delta (the most fertile agricultural zone). The Cauvery Delta zone, located in the humid tropics, has a mean annual rainfall of 1,273 mm, with more than 60% of that coming from the northeast monsoon. An analysis of summer monsoon rainfall (June–September) for 1871–1991 shows that the state experienced below-normal rainfall in 30% of these years. During the summer, the average rainfall is 266 mm, but water demand is 663 mm. Hence it is a deficit season. The northeast monsoon brings an average of 529 mm rainfall and demand is relatively low—361 mm.