Annual, Seasonal and Monthly Rainfall Variability at Dharwad in Karnataka

Abstract

Rainfall is one of the important weather factors deciding the economy, food habits, industries and work force of the area. Distribution of rainfall throughout the year further decides cropping pattern, variety to be cultivated and duration of the crop and management practices for efficient rainfall utility. In this regard 51 year past rainfall data (1970-2020) of Dharwad district of Karnataka was collected from Main Agricultural Research Station (MARS), UAS, Dharwad for analysing seasonal, annual and monthly variabilities. From the analysis we found that the rainfall varied in the range of 417 to 1316 mm with the average of 748 mm and with the variation of 22 per cent. Five years moving rainfall average showed declining trend. July month recorded highest average rainfall of 136 mm with the lowest variation (39 per cent). Though January month recorded lowest rainfall (one mm), the highest variation was observed in February. Southwest (Jun-Sept), Northeast (Oct-Dec), Winter (Jan-Feb) and Post monsoon (March-May) contributed 65 per cent, 19 per cent, 1per cent and 15 per cent, respectively of the annual rainfall of Dharwad district. The lowest variation in rainfall over the years was observed in Southwest monsoon (27 per cent) while winter season showed highest variation. Farmers can be advised to take long duration crops like Cotton and Maize in kharif because of nearly even distributed rainfall for the months from June- October and early sowing in case of rabi to harness the more moisture for better yield. Summer sowing should be avoided because of more uncertainty in rainfall.