Analysis of Spatial and Temporal Climate Characteristics in North Eastern Ethiopia: Case Study of North Wollo Zone

Abstract

In Ethiopia, agriculture is the most important sector; the corner stone of the economy; which is a source of livelihood for more than 85% of Ethiopians; and contributes nearly 50% of the Growth Domestic Product (GDP) of the country. However, the production performance of the sector is largely depending on the good will of seasonal climate characteristics due to its long-lasting marriage of rain-fed based farming system. Therefore, this study was aimed to investigate the climate characteristics of a region, in north eastern Ethiopia, using seventeen meteorological stations having 31 years of observed rainfall and temperature time series data. Rainfall variability of annual and seasonal climate characteristics were subjected for rainfall anomaly index and coefficient of variation statistics and Mann-Kendall trend test approach were applied to investigate trends of rainfall and temperature in the region over the last 31-years. The result shows that rainfall and temperature were varied across location and time. In this region, mean annual rainfall ranges from 531 mm; over some pocket areas of western, central and north eastern parts; to 1005mm in south eastern region of north Wollo. In terms of rainfall distribution, the area receives rainfall two times a year; from June to September (kiremt) and from Mid-February to Mid-May (Belg) period. In this regard, rainfall during belg is highly erratic and unstable relative to the main growing season. The location wide analysis concluded that variation in season onset; cessation and growing season length were observed across from location to location. According to the study, 4-July (DOY=166) and 4-Octoner (DOY=278), in respective order, were estimated as mean dates that the season starts and ends. Further, the analysis revealed, in general, the season onset ranges from 15-June (at Lalibela) to 16-July (at Tekulishi); and end of growing season varies from 21-September (Zobil) to 15-October (Sirinka). In general, investigating annual and seasonal climate characteristics; particularly the characteristics of onset, cessation and length of growing season: helps to undertake manageable farming practices that would be suited with local climate potentials. Indeed, climate information has a huge impact on management of seasonal farming activities that would be undertaken during preseason, in season, and post season farming activities.