Report on Historical Climate Baseline Statistics for East and West
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ReportHistorical on Climate Historical Baseline Statistics Climate for East and West Hararghe, Ethiopia Baseline Statistics for East and West Hararghe, Ethiopia Vol 2 Historical Climate Baseline Statistics for East and West Hararghe, Ethiopia ACKNOWLEDGMENT The report was prepared with substantial inputs and feedback from Ethiopia National Meteorological Agency, IGAD Climate Prediction and Application Center, World Meteorological Organisation, Food and Agricultural Organization. Additional inputs and comments were made by Oliver Kipkoge, Abdi Jama, Guleid Artan, Sebastian Grey, Deborah Duveskog. Analysis of climate change data and drafting of the report was made possible with inputs from Linda A. Ogallo, Tsegaye Ketema, Paulino Omay, George Kababka, and Ismael Lutta. Editor: Bahati Musilu Historical Climate Baseline Statistics for East and West Hararghe, Ethiopia 1 TABLE OF CONTENTS 1. INTRODUCTION ................................................................................................................................... ii 2. ETHIOPIA AND TARGET SITE ............................................................................................................. 4 2.1 East and West Hararghe ................................................................................................................ 6 3. CLIMATE BASELINES WORKSHOP .................................................................................................... 2 3.1 DATA ............................................................................................................................................. 2 4 BASELINE STATISTICS FOR EAST AND WEST HARARGHE ............................................................ 2 4.1 Mean Annual Rainfall ..................................................................................................................... 3 4.2 Monthly and Seasonal Rainfall Climatology .................................................................................... 4 4.3 Interannual Variability ..................................................................................................................... 7 4.4 Rainfall Trends ............................................................................................................................... 8 4.5 Mean Rainfall intensity ................................................................................................................. 10 4.5.1. Observed Variance in Rainfall intensity ................................................................................. 11 4.5.2. Probability of Exceeding Specific Rainfall Thresholds............................................................ 11 4.6 Mean Wet Days ............................................................................................................................ 12 4.6.1. Observed Variance in Wet Days ............................................................................................ 23 4.6.2. Probability of Number Wet Days ............................................................................................ 23 4.7 Mean Wet Spells .......................................................................................................................... 24 4.7.1 Probability: Wet Spells ........................................................................................................... 25 4.8 Mean Dry Days ............................................................................................................................. 25 4.8.1. Coefficient of variation: Dry Days .......................................................................................... 26 4.9 Mean Dry Spells ........................................................................................................................... 26 4.9.1. Coefficient of variation: Dry Spells ......................................................................................... 21 4.9.2. Probability: Dry Spells ........................................................................................................... 21 4.10 Climatological Baselines for Onset, Cessation dates and Length of Growing Period .................... 21 4.10.1. Onset ................................................................................................................................. 22 4.10.2. Cessation ........................................................................................................................... 22 4.10.3. Length of Season ............................................................................................................... 22 4.11 Temperature ................................................................................................................................. 22 i Historical Climate Baseline Statistics for East and West Hararghe, Ethiopia 4.11.1. Annual Mean Temperature ................................................................................................ 22 4.11.2. Seasonal Temperature Climatology ................................................................................... 26 4.11.3. Temperature Trends .......................................................................................................... 27 5 CONCLUSIONS .................................................................................................................................. 29 6 WORKS CITED ................................................................................................................................... 31 ii Historical Climate Baseline Statistics for East and West Hararghe, Ethiopia LIST OF FIGURES Figure 2.1-1 East and West Hararghe Districts and Divisions ....................................................................... 2 Figure 4.1-1 Annual Rainfall distribution (1981-2010) ................................................................................... 3 Figure 4.1-2 Annual maximum rainfall extremes 1981-2010 ......................................................................... 3 Figure 4.1-3 Annual minimum rainfall extremes 1981-2010 .......................................................................... 3 Figure 4.2-1 Mean Monthly rainfall (1981-2010) ........................................................................................... 4 Figure 4.2-2 February – May (Bega) seasonal rainfall (1981-2010) .............................................................. 5 Figure 4.2-3 June – September (Kiremt ) seasonal rainfall (1981-2010) ....................................................... 5 Figure 4.2-4 Monthly rainfall climatology (1981-2010) .................................................................................. 6 Figure 4.2-5 Seasonal Contribution of Belg (February – May) ...................................................................... 7 Figure 4.2-6 Seasonal Contribution of Kiremt (June - September) ................................................................ 7 Figure 4.3-1 Rainfall anomaly in March to May (1981–2010) for the East and West Hararghe region (Source: observed data blended with CHIRPS) ............................................................................................ 8 Figure 4.3-2 Rainfall anomaly in June to August (1981–2010) for the East and West Hararghe region (Source: observed data blended with CHIRPS) ............................................................................................ 8 Figure 4.3-3 El Nino/ La Nina index quantified by Nino 4.3 ONI index (NOAA) ............................................. 8 Figure 4.4-1 Rainfall Trend over East and West Hararghe in March to May Season (1981-2010) ................ 9 Figure 4.4-2 Rainfall Trend over East and West Hararghe in June to August Season (1981-2010) .............. 9 Figure 4.4-3 Rainfall Trend over East and West Hararghe in Belg (February – May) Season (1981-2010) ... 9 Figure 4.4-4 Rainfall Trend over East and West Hararghe in Kiremt (June - September) Season (1981- 2010) ............................................................................................................................................................ 9 Figure 4.4-5 Rainfall Trend over Hawi Gudina division during Kiremt Season (1981-2010) ........................ 10 Figure 4.4-6 Rainfall Trend over Goro Gutu division during Kiremt Season (1981-2010) ............................ 10 Figure 4.5-1 Seasonal Rainfall Intensity for Belg (FMAM) in East and West Hararghe (1981-2010) ........... 11 Figure 4.5-2 Seasonal Rainfall Intensity for Kiremt (JJAS) in East and West Hararghe (1981-2010) .......... 11 Figure 4.5-3 Belg (FMAM) Rainfall Intensity: Coefficient of Variance (1981-2010) ...................................... 11 Figure 4.5-4 Kiremt (JJAS) Rainfall Intensity: Coefficient of Variance (1981-2010) ..................................... 11 Figure 4.5-5 Probability of Rainfall intensity exceeding 5 mm Belg (FMAM) Seasons (1981-2010) ............ 12 Figure 4.5-6 Probability of Rainfall intensity exceeding 5 mm Kiremt (JJAS) (1981-2010) .......................... 12 Figure 4.6-1 Average Number of Wet days in the Belg (FMAM) Season (1981-2010) ................................ 12 Figure 4.6-2 Average Number of Wet days in the Kiremt (JJAS) Season (1981-2010) ............................... 12 Figure 4.6-3 Wet Days: Coefficient of Variance during Belg (FMAM) Season (1981-2010) ......................... 23 Figure 4.6-4 Wet Days: Coefficient of Variance during Kiremt (JJAS) Season (1981-2010) ........................ 23 Figure 4.6-5 Probability