Variability of rainfall and its current trend in Amhara region, Ethiopia

Abstract

In most of African countries whose economy is heavily depending on rainfed agriculture, accurate estimation of the spatial and temporal distribution of rainfall and observing its trends are crucial input parameters for securing sustainable agricultural production. This paper examines the spatial and temporal rainfall characteristics of Amhara Region, Ethiopia; using standard rainfall statistical descriptors. For this purpose, 10 meteorological stations with 30 years of daily rainfall data have been used. Variations of rainfall were found in every month in all stations. The spatial distribution of annual rainfall was varied from 850 to 1485 mm. Belg (“small rainfall” in March – May) rain makes a considerable contribution to the annual total in the central and eastern stations of the region. Annual rainfall has shown negative and positive anomalies for much of the 1980s and 1990s, respectively. Although the long term movements of rainfall in a time series did not show any increasing or decreasing trend, contraction of the length of growing period due to early cessation of rainfall had been observed in recent years. However, for improving precision and reliability of the application of the findings for practical use, increasing the number of study stations is found central. Key words: Africa, Ethiopia, Amhara, belg, spatial and temporal variability, rainfall trend.