Rainfall Variability of South-West Monsoon: A Special Study Based on Ratnapura District, Sri Lanka

This study was conducted using secondary data from the Meteorological Department obtained from five stations in Ratnapura District: Ratnapura, Eheliyagoda, Balangoda, Lellopitiya and Embilipitiya. The objective of the study was ‘to identify rainfall trend and variability analysis in the study area and to find the impact of climate changes on rainfall variability in the study area’. The average rainfall in the selected stations are: in Embilipitiya - between 112 mm to 170 mm, in Balangoda - from 170 mm to 230 mm, Lellopitiya – from 230 mm - 290 mm and both Ratnapura and Eheliyagoda - 290 mm to 360 mm. To identify the rainfall variability, the moving average technique was employed, using 7 years of data. According to the result of this study, climate change has impact on rainfall variability in the Ratnapura District.