Geo-Eye

Abstract

Abstract Theknowledge and the awareness of climate variability is an important factor to understand the nature of different climatic systems andtheir impact on the environment and the human development far and wide. In particular to that the Rainfall variability is an important feature of semi-arid climates and climate change is on the rise with suchvariability in many of these regions. The spatial study on the rainfall variability helps in understanding the trends for vulnerable drylandagriculturalists and policymakers to address theseclimate variationsfor future. The goal of this paper is to examine this climatic phenomenon in semi-arid region of Virudhunagar District in Tamil Nadu, which includes the spatial distribution, variability through different seasons and precipitation ratio. This will enable us to understand the frequent occurrences in that particular region for future climate adaptation. To reach these goals, the paper determines rainfall variability, monthly and annual trends in that variability based on 30 years of the monthly rainfall datafor 8 rain gauge stations and the results delineate to show the gradients in rainfall over the years from 1980 to 2010. The results also identify a trend towards decreased rainfall throughout the district in all stations, which is associated with decrease in the number of rainy days. Both the drying trend and decrease in rainy days agree with climate change for Virudhunagar District which is alarming the farmers of the region.

Keywords: Climate Variability,Rainfall variability, Rainfall trends, Climate change, Semi-arid climates, Precipitation Ratio.