Probability analysis of rainfall at Shivri for crop planning

Abstract

Probability analysis of rainfall offers a better scope for predicting the minimum assured rainfall to help in crop planning. An attempt has been made to evaluate rainfall distribution patterns i.e. weekly, seasonal, and annual rainfall, based on 13 years (2000-2012) data of Shivri, Lucknow, Uttar Pradesh. Expected weekly, monthly, seasonal, and annual rainfall values at different probability levels were determined by using Blom plotting function. The analysis reflects that the observed rainfall based on 13 years annual average was 829.35 mm emerging from an average rainy days of 40.7. The predicted annual rainfall at 75% probability level is 636.5 mm. Similarly, at 75% probability level, the highest weekly rainfall of 42.0 mm predicted in 37th week followed by 38.6 mm in 27th standard week, and lowest rainfall of 0.0 mm in 40th week. Whereas, analysis of monthly rainfall at 70, 75 and 80% probability levels shows that July, August, and September are the three important wet months having chances of receiving a monthly rainfall between 100 to 150 mm. The predicted value of seasonal rainfall shows 600 mm during kharif season at 70% probability level, whereas the same was 12.6 mm in case of rabi and 4.2 mm in case of zaid cropping seasons.