Analysis of Spatiotemporal variability and trends of rainfall among the Agro-Climatic Zone of Abiya Watershed, Northwest Ethiopia

Abstract

Abstract Studies like this have a paramount advantage in area where rain-fed agriculture is dominant. The objective of this study was to analyze the spatiotemporal variability and trends of rainfall among the agro-climatic zones of Abiya Watershed. The study employed 50 sample grid points from CHIRPS for the period 1981–2019 with a spatial resolution of 5km\(\times\)5km. Coefficient of variation (CV), precipitation concentration index (PCI), and Standardized anomaly index (SAI) were used to analyze rainfall variability. Mann Kendall’s (MK) and Sen’s slop have used to define the trends and magnitude of the changes in rainfall amount. The CV output shows low, moderate, and high variability of monthly and seasonal rainfall and low inter-annual variability. The PCI of the watershed showed uniform seasonal rainfall distribution (summer and spring), strong irregular seasonal rainfall distribution (winter), and irregular annual rainfall distribution, and the SAI perceived the existence of inter-annual and inter-seasonal variability of rainfall with a greater negative anomalies percentage. The MK output presented, most of the months were increased and all increased in the annual and seasonal rainfall. The information obtained from this study was used as input for decision-makers to take appropriate adaptive measures in agricultural sectors.