Seasonal climate variability analysis and characterization for major crops and vegetables production in Siraro-Kofele potato-vegetable livelihood zone of Ethiopia

The failure or the success of seasonal and annual rainfall amount and distribution is extremely critical for rain fed agriculture. The objective of this study was to analyze, examine, and characterize the seasonal and inter-annual temporal variability of rainfall variables, and understand and identify degree of vulnerability of crop production to rainfall variability in Siraro-kofele potato-vegetable livelihood zone. Instat software version +v.3.37, R-statistical package and Excel 2010 were used for analysis. Annual and seasonal rain fall amount was more variable at Aje where rainfall amount is less. In all climatic parameters; coefficient of variation was showed high variability in Belg than Kirmet. Variability of season onset, cessation, length of growing period, dry spell of different length and changes in number of rainy days indicated high year to year or season to season variability and were the most determinant climatic factors of crop production of the livelihood zone. Length of the growing period of Belg was more explained by onset while of main rainy season more influenced by cessation of the season. Most of drought prevailed during the study period were mild drought followed by moderate and manageable. Contrary to this wet condition is also frequently exhibited during study period. Rainfall variability and crops yield was showed direct relationship. Observed Teleconnection between rainfall regimes and large scale climate patterns sea surface temperature and southern oscillation index revealed positive results towards better understanding of the causes of climate extreme events. Kiremt rain was positively and negatively correlated to the Southern oscillation index and Sea surface temperature anomalies respectively. The more variable Belg rain describes the opposite. Temperature variability and calculated Growing Degree-Days also showed positive and negative relation with crops yield. However, for improving precision and reliability of the application of the findings for practical use, increasing the number of study stations and further intensifying climate related research are critically important.