Climate scenarios at the Kabe Watershed Pilot Project in Ethiopia, 2011-2013

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

Gashaw Bimrew (Wollo University)

Climate scenarios at the Kabe Watershed Pilot Project in Ethiopia, 2011-2013

• 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.

1. Background

• 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.

2. Methods

Analysis of climate change and variability

Climate changeClimatological mean periods

1981-2007

2011-2040 2041-2070

2071-2100

Mean annual total rainfall(mm)

839.9 823.7/-.92% 848/+0.96%

839.8/-0.01%

Mean monthly average air temperature(0C)

13.6 14.8/+1.3 15.6/+2.0 15.9/+2.3

Climate variabilityTime period of the study

Temperature

Warmest month

Coldest month

Warmest year

Coldest year

1981-2007 June 15.90C

November 11.70C

1987 (14.30C)

1984 (12.50C)

2013-2042 May 17.40C

December with 12.50C.

2042 (15.8 0C)

2020(14.10C

Difference +1.50C + 0.80C +1.50C +1.60C

3. Findings

Rainfall variability Rainfall regime of the past:-

– 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 time period

Past rainfall variability

(1981-2007)

Remark Future rainfall variability

(2013-2942)

Remark

Mean (mm) Percentage from total (%)

PCI (%) CV Mean Percentage from total (%)

PCI (%) CV

Annual rainfall

839.9 100 30 0.18 Less variable

835.1 100 30.1 0.182 Less variable/-0.57%

Kiremt rainfall

626 74.5 July

and August

0.24 moderately variable

616.1 73.8 August and September

0.187 Less variable/-1.6%)

Belg rainfall 175 20.8 0.49 Highly variable

84.8 10.2 0.64 Highly variable/+245.7%

Bega rainfall

38.82 4.6 0.67 Highly variable

134.2 16 0.56 Highly variable/-103.9%

Time period of the study

Length of growing Remark

Onset time

Offset time LGP/days

Past from 1981-2007

June August 65-90 Failure of Belg and some years with no growing season

Future

2013-2042

June October 125-135 Failure of Belg, Emerging on Bega as a growing season

Suitable to rain-fed agriculture

Length of growing season

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.

4. Conclusion/ recommendation