Analysis of Rainfall Variability and Probability in Parbhani District, Maharashtra, India

Daily data of 30 years (1987-2016) was used to find rainfall variability & probability distribution, wet & dry weeks and incomplete gamma distribution analysis at Parbhani. The annual and seasonal rainfall data has analyzed statistically and different statistical parameters like mean, median, standard deviation, coefficient of variation, coefficient of skewness and kurtosis. Weekly initial and conditional probabilities of dry and wet spell for monsoon and post-monsoon rainy season for 20 mm, 40 mm, 60 mm and 80 mm for the 22nd (28th May to 3rd June) to 48th (26th November to 2nd December) Standard Meteorological Week were determined, to obtain specific information needed for crop planning and for carrying out agricultural operations. The probability of occurrence of wet week preceded by another wet week is higher from 23rd to 39th SMW. Incomplete gamma probability distribution for weekly rainfall shows that there was 90% probability of getting an assured rainfall of at least 641.6 mm and more than 20 mm of rainfall could be expected during 24th to 36th and 38th SMW with 50 % probability, which shows the potentiality for rain water harvesting. Therefore, it is required to create the means for the storage of rainfall that can be utilized in the hard time to meet the shortage of water.