Evaluating the effects of El Niño phenomenon on the flow and flooding of the Karun River in the historical statistical period

In this research, using the Oceanic Ninoy Index (ONI) during the statistical period of 1334 to 1401 water years, El Nino and La Niña periods have been identified and simultaneously with these periods, the natural monthly flow of the Karun Basin and the floods that occurred in the Karun River in The location of Karun Dam 3 has been obtained and compared. As a result of investigating the amount of flow and flood intensity in El Niño periods and comparing it with other situations, it was found that on average, in different seasons, the natural flow of Karun basin increases by 6 to 27% in El Niño periods. The highest increase is related to the fall season and the lowest increase is related to the summer season. Also, the most severe floods of the Karun river occurred simultaneously with the El Nino situation, and it seems that the intensity of the El Niño has a direct relationship with the intensity of the floods of this river.