Climate variability trend and extreme indices for the Thanjavur Delta region of Tamil Nadu in South India

Abstract

The Thanjavur delta region of Tamil Nadu vastly depends on agriculture.The current trend of agricultural production has been significantly affected due to changes in climatic conditions.The observedparameters have been acquired from IMD (Indian Meteorological Department) for the period 1971-2014 and CCAFS (Climate Change, Agricultural and Food Security) over the period 2015-2050 for climate trend and extremities analysis. This study indicated that observed maximum temperature (TMax) has significantly increased about 0.8 ºC, 1.5 ºC and 0.9 ºC in ARP, NPT and IMD grid, respectively, over the period 1971-2014. Besides that, minimum temperature (TMin) has shown an insignificant trend in ARP and NPT and a significant trend in the IMD grid (0.5 ºC), respectively. Moreover, the observed rainfall showed an insignificant trend in ARP (-3.8%), NPT (-11.1%) and IMD grid (+22.5%). The projected TMax & TMin showed a significant increasing trend of about 1.05 °C and 1.1 °C, respectively, and the rainfall is projected to decrease insignificantly at 21% over the period 2015 to 2050. In the extreme analysis of the delta region, temperature indices showed a significant increasing trend inboth the observed and future. The rainfall indices showed a larger variation in the observed and future period. The study's outcome would be useful in framing the climate change adaptation strategies for agriculture and water sectors for the Thanjavur delta region.