Effect of El Niño and La Niña on seasonal and annual rainfall in different districts of Chhattisgarh state

The present investigation was carried out to study the occurrence and frequency of El-Niño and La-Niña events during 1951-2023 and study the effect of El Niño and La Niña events on rainfall during the period of 1960-2023 at Department of Agricultural Meteorology, Indira Gandhi Krishi Vishwavidyalaya, Raipur (Chhattisgarh). During this long period 1951-2023,11 weak El Niño events, 7 strong El Niño events, 6 moderate El Niño events, 3 very strong El Niño events and 12 week La Niña events, 6 moderate La Niña events and 7 strong La Niña events were found out of 73 years. The average annual and S-W monsoon season rainfall during El Niño years was found to be affected and both negative and positive deviation in rainfall were found. The most of the districts observed negative deviation in rainfall. During La Niña years, annual and S-W monsoon season rainfall, both positive and negative deviation in rainfall were found. Most of the districts observed positive deviation in rainfall.