Ecology, Environment and Conservation Paper

CLIMATE CHANGE PROJECTIONS FOR CUDDALORE DISTRICT OF TAMIL NADU, INDIA USING A REGIONAL CLIMATE MODEL- PRECIS

Thirumurugan Perumal, Krishnaveni Muthiah, Ramachandran Andimuthu, Prasanta Kumar Bal and Rajadurai Geetha

Abstract

This study presents the regional climate change over Cuddalore district of Tamil Nadu state, India by using PRECIS, a Regional Climate Model (RCM) developed by Hadley Centre-UK Met office. The model is run with 25km x 25km resolution by using lateral boundary conditions from the Global Climate Model (GCM) - HadCM3Q at the emission rate of SRES A1B scenarios. The results are considered from the ensemble member HadCM3Q0 running over a period of 130 years to predict the future climate change. The analyses concentrate on maximum temperature, minimum temperature and rainfall over the region. For Cuddalore district as a whole, the projections of maximum temperature show an increase of 1.2 0C, 1.7 0C and 3.4 oC for the periods 2020s, 2050s and 2080s respectively with respect to baseline period (1970-2000). Similarly, the projections of minimum temperature show an increase of 1.2 oC, 2.3 0C and 3.6 oC respectively. The annual rainfall projections for the three projections indicate a general decrease in rainfall being about 7%, 5% and 2% respectively; however, some exceptions are noticed over coastal areas where there is an increase in rainfall intensities are seen. The trend analyses have been performed using Mann-Kendall trend test at 0.05 significance level for both surface temperatures and rainfall data series and the increasing trends in case of temperatures indicate significant trends.