Rainfall Trend and Variability over Western Amhara, Ethiopia

Climate change has become a pressing global challenge, with rural communities in Ethiopia among the most vulnerable due to their dependence on rain-fed agriculture. This study examined rainfall variability and trends in Western Amhara, Ethiopia, from 1992 to 2021 using daily rainfall data from eleven meteorological stations. Analytical methods included the Coefficient of Variation (CV), Precipitation Concentration Index (PCI), Standardized Rainfall Anomalies (SRA), and Mann-Kendall trend tests, supported by Climate Data Tool (CDT) software. Results revealed considerable spatiotemporal rainfall variability, with annual totals ranging from 995 mm to 1783 mm and a mean of 1316 mm. The PCI analysis indicated irregular to strongly irregular rainfall distribution, particularly in Bahir Dar, Metema, and Nefas Mewucha. The lowest precipitation concentration index was found at Chagni and Debre Markos stations, with a value of 16.6. Seasonal analysis showed that the Kiremt rains contributed the largest share of annual totals, with higher variability compared to annual averages. Standardized anomalies highlighted alternating wet and dry years, signaling recurrent drought and excess rainfall events. These findings underscore the importance of rainfall variability as a determinant of food security, agricultural productivity, and water resource management. Understanding such variability is crucial for designing adaptive strategies to enhance resilience among farming communities in Ethiopia.