Department of Geography, School of Geosciences, Bharathidasan University, Tiruchirappalli, 24, rathodishappa@gmail.com.
Among the climatic elements the rainfallis the first index, ever thought of by farmers and climatic analyzers as it is the most important single factor which determines the cropping pattern of an area in general and the type of crop to be cultivated and its success or failure in particular. Therefore, the present study deals the rainfall characteristics of the Coimbatore District, which includes the spatial distribution and variability through different seasons, precipitation ratio and frequency occurrences. The study is based on 49 years of the monthly rainfall data for 33 rain gauge stations. While analyzing the long termaverage of monthly and annual rainfall, the annual rainfall of the district is 1242 mm, of which the winter, summer, southwest and northeast monsoon record 2.07, 14.97, 46.13 and 36.83 mm respectively. The station Upper Niradam receives the highest rainfall of 4655 mm whereas Krishnapuram records the lowest of 414 mm. The annual variability ranges from 21.16 percent to 52.28 percent. The south, southwest and northwestern partsof the district experience the heavy rainfall whereas the least rainfall areas are the east, northeast and southeastern parts of the district.
Annual and seasonal rainfall, rainfall variability, precipitation ratio and frequency
