Rainfall variability and its seasonal events with associated risks for rainfed crop production in Southwest Ethiopia

Abstract

AbstractRisks associated with rainfall variability are one of the most visible concerns of rainfed agricultural production in underdeveloped nations. Exploring the variability of rainfall and the risks connected with it is important for developing offsetting strategies. The purpose of this study was to investigate the variability of rainfall and its seasonal characteristics, as well as the associated risks in Southwest Ethiopia. Daily rainfall and temperature data of 12 weather stations were collected from the National Meteorological Agency of Ethiopia for the period 1983 to 2016. ArcGIS was used to examine the regional distribution of rainfall variability at temporal scale. INSTAT+v3.37 software was used to assess the monthly and seasonal rainfall distribution, start and end of season, length of growing season, and dry spells. The coefficient of variation for annual, spring, summer, and autumn rainfall ranged from 17.79 to 29.93, 21.23 to 41.56, 36.38 to 122.00, and 32.37 to 68.08%, respectively. The start and end date of rain during the spring season varied from 65 to 129 and 122 to 176 day of the year, respectively. Rainfall variability was linked to risks such as late onset, early cessation, short and prolonged dry periods, and drought with a high frequency and moderate-to-severe intensity.

Keywords

• dry spell
• drought
• end date of rainfall
• onset of rainfall
• variability