Trends in Biosciences

Rainfalls are one of important climate elements. The rainfalls distribution across time and space would impact human life, not only contribute on human wealth but also restricted human life. Rainfall is characterized by its amount, intensity and distribution over time. In order to understand the spatial pattern of annual and seasonal rainfall of Nilgiris district, their variability and precipitation ratio of rainfall have been analyzed in ArcGIS environment. The study has used long term (35 years) mean monthly rainfall data for 19 rain gauge stations in the 4B2D5 watershed in the Southern part of Nilgiris district to analyze the seasonal pattern. The mean annual rainfall is about 1765 mm which exceeds 3012 mm and drops as much as 943.44 mm.