Aberrations in south-west monsoon rainfall at Cuttack region of Orissa and suitable crop planning

The 60 years (1941-2000) daily rainfall data recorded in the Agrometeorology observatory of the Central Rice Research Institute, Cuttack (20.5 °N and 23.5 m above mean sea-level) located in the Eastern and Southern Central agroclimatic zone of Orissa were critically examined for establishing long-term averages of monthly rainfall during the monsoon season and its temporal variability by deploying appropriate statistical techniques. The average monsoon rainfall (monthly total) of 1 313.6 mm was distributed in the proportion of 14.3, 25.6, 27.1, 19.2 and 13.7% from June to October respectively. The variabilities in normal rainfall during crucial months of June (55%) and October (77%) were relatively higher than the remaining monsoon months. The probabilities of both the normal onset (23rd standard meteorological week) and withdrawal (42nd standard meteorological week) of monsoon rain were same, ie 43.3%. The probabilities of aberrations in seasonal (June to October) amount of rainfall was 68.4% with higher proportion of below-normal (38.3%) than its above-normal rainfall (30.1%) during June to October. At 25% and 50% probabilities, the stable quantum of rainfall was observed during 24th-41st and 25th-38th standard meteorological week respectively.