| dc.description.abstract | Climate change is expected to increase both the magnitude and frequency of extreme precipitation
events, which may lead to more intense and frequent river flooding. This study evaluated the
impact of climate change on water balance components and flood hazard in the Lower Mono river
Basin through rainfall- runoff modelling. The projection from two West African Science Service
Center on Climate Change and Adapted Land Use (WASCAL) climate model, GFDL-ESM2M
and HadGEM2-ES under RCP 4.5 and the hydrological model HBV (Hydrologiska Byråns
Vattenbalansavdelning) - light is considered in this study. HBV model was set up for the study
area and the modelcalibration and validation was performed against the observed discharge
measurments. Statistical bias correction (empirical quantile mapping) was applied to daily
precipitation, temperature and evapotranspiration. Uncorrected and bias corrected climate data was
then used as input for HBV model to simulate the water balance components. Considering both
uncorrected and bias corrected climate variables, the projected climate change signal for the Basin
was analyzed through the comparison between two future periods (2020- 2049 and 2070-2099)
and the historical time period (1983- 2005). The impact of the detected climate change signal on
flood frequency was then assessed using HYFRAN software. The results indicated that: (i)
precipitation will increase by 19% and 35%; temperature increases from 0 to 1.17°C and 1.17 to
3.20°C; actual evapotranspiration increase by 9% and 20% and discharge increase by 59% and
102% respectively for the periods 2020-2049 and 2070- 2099 according to HadGEM2-ES model.
GFDL-ESM2M model also illustrates an increase in precipitation by 15% and 30%, temperature
from 0 to 6.5°C and 6.5°C to 7.41°C but a decrease in discharges by 58% for 2050 and by 44%
for 2100 repectively. In case of impact of the climate change signal on flood frequency, the
average change resulting from the two models indicated a decrease for the return periods 50, 20,
10, 5, 3 for future periods 2020-2049 and return period 50 for the period 2070-2099 whereas an
increase for the return periods 3, 2 (2020-2049) and 20, 10, 10, 5, 3 and 2 (2070-2099).These
results suggest for future flood management under climate change in Mono river basin to consider
both increase and decrease in the flood frequency as the study shows that both trends are plausible | en_US |
