Spatiotemporal variability and trends in rainfall extremes in Enebsie Sar Midir district, northwest Ethiopia

Abstract

The main purpose of this study was to investigate the spatiotemporal variability and trends in rainfall extremes in Enebsie Sar Midir district, northwest Ethiopia, based on the data obtained from National Meteorological Agency of Ethiopia. Mann–Kendall’s test and Sen’s slope estimator were used to analyze the trend and magnitude of change, respectively. The results revealed that the annual rainfall showed increasing trend at all stations except at Mertu Lemariam, but the trends were not statistically significant. Trends of extreme rainfall events did not show systematic pattern. The maximum 1 day (Rx1 day) precipitation value decreased at Gundowoin, while the values increased at Mertu Lemariam and Motta. The trends for the mean annual consecutive 5 days (Rx5 day) precipitation, mean annual heavy (R10 mm) precipitation and mean annual very heavy (R20 mm) precipitation for annual time series were decreasing at Mertu Lemariam, while the trends were increasing at Gundowoin. The mean annual wet day rainfall intensity (SDII) for both the annual and main rainy seasons’ time series showed increasing trends but not statistically significant. The mean annual number of wet days, the mean annual consecutive wet days and the mean annual consecutive dry days at Gundowoin for both the annual and the main rainy seasons’ time series showed increasing trends, but the trend was only statistically significant for during the annual time series. The study has paramount significance for small-holder farmers to design appropriate adaptive strategies to climate-induced risks.