Climate scenarios at the Kabe Watershed
Pilot Project in Ethiopia, 2011-2013
Gashaw Bimrew (Wollo University)
Workshop on the lessons and success stories from a
pilot project on climate change adaptation
interventions in Kabe watershed, south Wollo,
Ethiopia, Addis Ababa, 11-12 February 2013

1. Background
• Kabe watershed has been battered by recurrent drought and it
needs a tailored made climate prediction.
• Climate predictions are important to design appropriate
acclimatization strategies, establish appropriate growing season
and avert food insecurity and create climate resilient society.
• Hence, this study was initiated to a) analyze and interpret the
past and the future climate change, climate variability and
extremes, and b) identify growing seasons of the past and
develop appropriate growing seasons of the future.

2. Methods
• Models groups from CMIP5
• Validation:-
– Using R2 and significant test
– CCSM4 45r3 data outputs for rainfall
– EC-EARTH 45R1 for temperature
– The evaluation of climate change, climate variability was
done using statistical parameters and climate induces.
– For the growing season
• Thornthwait method to PET
• the concept of growing period that uses rainfall and
PET method were applied.

3. Findings
Analysis of climate change and variability
Climate change Climate variability
Climatologi 1981- 2011-2040 2041- 2071-
Time Temperature
cal mean 2007 2070 2100
period of
periods
the study
Mean 839.9 823.7/-.92% 848/+0.96 839.8/- Warmes Coldest Warmes Coldest
annual total % 0.01% t month month t year year
rainfall(mm)
1981-2007 June November 1987 1984
15.90C 11.70C (14.30C) (12.50C)
Mean 13.6 14.8/+1.3 15.6/+2.0 15.9/+2.3
monthly 2013-2042 May December 2042 2020(14.
average air 17.40C with (15.8 0C) 10C
temperature 12.50C.
(0C)
Difference +1.50C + 0.80C +1.50C +1.60C

 Rainfall regime of the past:- Rainfall variability
– Bimodal nature with Kiremt
maximum and Belg minimum
– Bega the third season with no
significant rainfall.
 Projected rainfall regime
– Shift from Belg and Kiremt
bimodal to Kiremt maximum
(uni-modal)
– Potential to shift to Kiremt
maximum and Bega
minimum (bimodal season)

Rainfall Past rainfall variability Remark Future rainfall variability Remark
time
period (1981-2007) (2013-2942)
Mean (mm) Percentage PCI (%) CV Mean Percent PCI (%) CV
from total age
(%) from
total
(%)
Annual 839.9 100 30 0.18 Less 835.1 100 30.1 0.182 Less variable/-0.57%
rainfall variable
Kiremt 626 74.5 July 0.24 moderately 616.1 73.8 August 0.187 Less variable/-1.6%)
rainfall variable and
and August Septembe
r
Belg rainfall 175 20.8 0.49 Highly 84.8 10.2 0.64 Highly variable/+245.7%
variable
Bega 38.82 4.6 0.67 Highly 134.2 16 0.56 Highly variable/-103.9%
rainfall variable

Length of growing season
Time period Length of growing Remark
of the
study Onset Offset time LGP/day
time s
Past from June August 65-90 Failure of Belg and
1981-2007 some years with no
growing season
Future June October 125-135 Failure of Belg, Emerging
on Bega as a growing
season
2013-2042
Suitable to rain-fed
agriculture

4. Conclusion/ recommendation
The anticipated rise of temperature and the shift of
the growing season to Kiremt maximum and
emerging of Bega with significant amount of rainfall
requires appropriate acclimatization strategies to
minimize risks, increase crop productivity, shortage
of water resources and physiological disruption.