Trends in temperature, temperature humidity index and climate change at Seven Agro–climatic Regions of Tamil Nadu

Dr. Suraj; P.T; Dr.T.Sivakumar; Dr.A.Paramasivam

Volume : V, Issue : XI, November - 2015

Trends in temperature, temperature humidity index and climate change at Seven Agro–climatic Regions of Tamil Nadu

Dr. Suraj, P. T, Dr. T. Sivakumar, Dr. A. Paramasivam

Abstract :

In order to understand the climatic change happening in the different agro climatic regions of Tamilnadu,climatological data during the period 1955– 2005 were obtained from Indian Meteorological Department, Pune. From the basic temperature data mean maximum, mean minimum and Temperature Humidity Index (THI) was computed for each month for the seven agro climatic regions of Tamilnadu. Mean maximum temperature was observed at the month of May and Cauvery Delta zone showed maximum temperatureof 38.22 ± 1.33 ºCwith significant difference of P<0.01 between the regions. Mean minimum temperature was observed at the month of January and Hilly zone showed minimum temperature of 5.59±1.31 ºC with a significant difference of P<0.01 between the regions. The T max showed an increase in all the agro–climatic zones except in North Western Zone and Southern Zone. T min also showed a positive growth pattern in all agro–climatic zones except in North Western Zone and Southern Zone. Five agro–climatic zones viz. North Eastern zone, Western zone and Hilly zones, Cauvery Delta Zone and High Rainfall zone were showing a positive annual compounded growth rate for both morning and evening THI. In North Western zone the growth in THI was limited to morning and the evening THI showed a negative growth. Southern zone showed a negative annual compounded growth rate for both morning and evening THI.