Impact of Climate Change on Irrigation Case Study on Wonji Shoa Sugar Plantation Estate

Irrigation is significant in increasing agriculture production and productivity for the sustainability of the country's economy. Impacts on existing activities for irrigation design and management systems are obvious due to the rapid change of climate system. This paper's future focus is to evaluate the influence of the changing climate on the crop yield and irrigation requirement for the Wonji Shoa sugarcane plantation estate. For future climate data, it used the results of projections of the CORDEX regional climate model (RCM) with bias correction for medium concentration representative pathway 4.5 rcp and high concentration representative pathway 8.5 rcp scenario. The down-scaled data were then used as input to the AquaCrop model. The time series indicates a significant increasing trend in maximum and minimum temperature values and a slight increasing trend in precipitation for both 4.5 rcp and 8.5 rcp scenarios. The evapotranspiration shows an increase in 20.34%, 20.12%, 23.59%, and 24.36% for 8.5 rcp in the period of 2020s, 2040s, 2060s, and 2080s, respectively. For 4.5 rcp scenario, the change is about 8.4%, 11.65%, 13.22%, and 15.85% for the period of 2020s, 2040s, 2060s, and 2080s, respectively. The model output shows that there is an annual increase in yield. For 8.5 rcp scenarios, the incensement is 6.2%, 7.84, 11.03%, and 14.48% in the 2020s, 2040s, 2060s, and 2080s, respectively. For 4.5 rcp scenarios, the increment is much lower compared to 8.5 rcp scenarios. But there is still an increase in yield for 4.5 rcp. The change is 0.3%, 1.8%, 7.02%, and 4.82% for the period of 2020s, 2040s, 2060s, and 2080s, respectively.