Abstract:
This study assesses the impact of future climate change on the Baro-Akobo river basin
reservoirs in particular to Baro-1 and Baro-2 reservoirs which are going to be
implemented in the near future. The study focuses on their capabilities to hydropower
generation under future climate change. To know the level of impact of climate change
on the reservoirs. water availability and power generation potential, climate change
scenarios of precipitation and evapotranspiration were developed for two future periods
of 30 years from the year 2021 until 2080. The ERA-40 re-analysis predictor variables
data was used to develop the downscaling models. The outputs of ECHAM5 coupled
atmosphere-ocean GCM model for the A2 SRES emission scenarios were used to
produce the future scenarios. These outputs were statistically downscaled to the
watershed scale through developed regression models. Monthly water balance model was
used to simulate inflows to the reservoirs. The performance of the model was assessed
through calibration and validation process and the R2
resulted from 0.66 to 0.75 during
calibration and from 0.64 to 0.72 during validation at the two gauging stations. The
simulated inflows were used to simulate the hydro power potential of the reservoirs using
WEAP model for further impact assessments. The generated future scenario for
precipitation showed an annual increment at the three stations in the study area. At monthly level the precipitation amount showed an increasing trend in all months except
in the months of March and June. Generally higher increment of average monthly
precipitation amount observed during the dry season as compared to the main rainy
season. Comparison of the base period and the future period average annual inflow
volume showed an increase of 4.78% during the 2021-2050 period and 10.66% during
the 2051-2080 period at Baro-I reservoir. At Baro-2 reservoir, an increase of 4.83 %
during the 2021-2050 period and 10.74% during the 2051-2080 period and at Genji an_nual power generation might increase by 2.3% and in the period 2051-2080 it might
also increase by 4.3 % in comparison to the base period at Baro-2 hydropower station.
