ENSO and Flooding on the Mohawk River from April to September 1950–2017

ENSO and Flooding on the Mohawk River from April to September 1950 to 2017

The overall purpose of this research was to see if there was a relationship between the El Niño-Southern Oscillation (ENSO) and if they affected flooding in the Mohawk River watershed in New York state at five different station locations. Specifically, this work examines flooding in Rome, Little Falls, Schenectady, Gilboa, and Cohoes from April to September from 1950 to 2017. Data for this study included stream gauge height data and recording the amount of times each station rose above flood stage. Only the number of times the river flooded was recorded, and not the actual height above the banks. The ENSO phases from 1950 to 2017 were also recorded. A major trend that was seen was that during a La Niña phase, there was more tropical and non-tropical flooding. In this study, the authors discovered that more non-tropical floods, which are floods events that are not caused by tropical events, such as a hurricane, occur during a La Niña phase rather than during a Neutral or El Niño year. El Niño phases exhibited more non-tropical flooding when compared to a Neutral year and there were more tropical floods, which are flood events directly caused by a hurricane, tropical storm or tropical depression, during a La Niña than any other phase. Based on the findings, one reason why there was more non-tropical flooding in a La Niña than any other phase is because La Niña brings in more precipitation over the region. Although La Niña does not occur as frequently as an El Niño, La Niña is known to last longer with colder and stormier conditions.