No abstract

Consequently, the spatial and temporal variability of water resource, or in general the water balance, can be significantly which in turn affects agriculture, industry and urban development. Climate change is expected to have adverse impacts on socio economic development globally; the degree of the impact will vary across nations [7].

No abstract

Climate change is likely to affect the hydrology and water resources availability of upper Blue Nile River basin. Different water resource development projects are currently existed and under construction in the region. In order to understand the future impacts of climate change, we assessed the hydrological response of climate change of four catchments (Gilgel Abay, Gumer, Ribb, and Megech) of the upper Blue Nile River basin using new emission scenarios based on IPCC fifth assessment report (AR5). Five biased corrected 50 kms by 50 kms resolution GCMs (Global Circulation Model) output of RCP 4.5 and RCP 8.5 emission scenarios were used. The future projection period were divided in to two future horizons of 2030`s (2035-2064) and 2070`s (2071-2100). The Hydrologic Engineering Center-Hydrological Modelling System (HEC-HMS) was calibrated and validated for stream flow simulation. All the five GCMs projection showed that, maximum and minimum temperature increases in all months and seasons in the upper Blue Nile basin. The change in magnitude in RCP 8.5 emission is more than RCP 4.5 scenario as expected. There is considerable average monthly and seasonal precipitation change variability in magnitude and direction. Runoff is expected to increase in the future, at 2030`s average annual runoff projection change may increase up to +55.7% for RCP 4.5 and up to +74.8% for RCP 8.5 scenarios. At 2070`s average annual runoff percentage change increase by +73.5% and by +127.4% for RCP 4.5 and RCP 8.5 emission scenarios, respectively. Hence, the increase in flow volume in the basin may have a significant contribution for the sustainability of existed and undergoing water development projects. Moreover; it will help for small scale farmer holders to harness water for their crop productivity. However, a precaution of mitigation and adaptation measures ought to be developed for possible flooding in the flood plains area of the River basin. to determine the hydrological response to climate change for the sustainability of the projects and looking for the possible mitigation measures otherwise all the cost indebted will be lost in failing to meet the objectives. In this study, the new RCP (Representative concentration path) climate scenarios data of the future climate output under assumed radiative forcing scenario will be used for each catchment in the River basin. Then the data will be used as input to the hydrological model (HEC-HMS 3.5) to simulate the effect of climate on the hydrological regimes of the catchments.In this study the upper Blue Nile River Basin (Gilgelabay, Gumera, Ribb, and Megech) catchments will be modelled and the impacts of the climate change using (RCP 4.5 and RCP 8.5 emission scenarios) climate data will be used to analyse the future water availability in the region. Description of the Study AreaThe upper Blue Nile River basin which is located in the Ethiopian Highlands. The Blue Nile River runs from its origin, Lake Tana, to the Sudanese border and eventually meets the White Nile River at Khartou...