Impacts of El Niño-Southern oscillation on rainfall amount and anticipated humanitarian impact

In East Africa, agricultural production is predominantly rain-fed. The El Nino Southern Oscillation (ENSO) is the driver of climate variability, which affects rainfall amount that leads to humanitarian impact. This paper aims to study the impacts of El Nino Southern Oscillation (ENSO) on rainfall amount and anticipated humanitarian impact. The study was carried out in Western Amhara in Amhara National Regional State of Ethiopia, which features a variety of seasons that characterize the nation and Eastern Africa. Monthly rainfall data were collected from fifteen meteorological stations of Western Amhara service center. Selected El Nino and La Nina years were also extracted from the National Oceanic and Atmospheric Administration (NOAA) from 1986 to 2015. Once the data quality was checked and inspected, the monthly rainfall data of the selected stations was arranged in a Microsoft Excel spreadsheet and analyzed using XLSTAT software. The coefficient of variation and the Mann-Kendall nonparametric statistical test were employed to analyze trends and variability of rainfall and temperature. The long-term recorded annual rainfall data indicated that there was an increasing trend from 1986 to 2015 insignificantly Western Amhara. El Nio's effects are predicted to lead to more severe and violent heatwaves, wildfires, floods, droughts, and diseases in East African countries like Ethiopia, Sudan, and Somalia, which are already dealing with humanitarian challenges. The rainfall variability was less (Coefficient of Variation, CV = 8.6%); also, the mean monthly rainfall of Western Amhara decreased during El Nino years and increased during La Nina years especially in the rainy season (June, July, August and September) over 30 years. This finding will be useful to suggest possible adaptation strategies and efficient use of resources during planning and implementation.