الفهرس | Only 14 pages are availabe for public view |
Abstract Many development projects involving Nile waters are currently underway or being studied. These projects will lead to changes in land-use patterns, and affect water distribution and availability. It is important to assess the effects of a) these projects, and b) evolving water resource management and policies, on regional hydrological processes. This research seeks to establish a basis for evaluation of such impacts within the Nile River sub-basin, using the RegCM3 Regional Climate Model to simulate interactions between the land surface and climatic processes. The research, presents the analysis of the climate effects of land use change for Baro-Akobo subbasins based on two relatively long (25years) regional model (RegCM3) simulations. Two different vegetation cover datasets are employed, one representing the current land use and the other representing the potential vegetation cover without human intervention. The possible effects and feedbacks induced by anthropogenic land use change on the climate of Baro-Akobo are analyzed based on the differences in various simulated climatic variables between the two simulations. The result for ECHAM A1B scenario is estimated as following; 1)The annual precipitation will increase by 15%; 2)The average Temperature change for the dry months is vary from 1.9C0 to 4.0C0 however the change during wet months is vary from the 1.0C0 to 2.0C0; 3) The daily evapo-transpiration rates showed a small change (+2% to +5%) during the dry months although the increase in the evaporation rate is reach 13 % during the wet months; 4) The overall annual change in flow is small (+3.0%). However, the seasonality of flow increased. In average, early flood season flows in JJAs increase by (+11%), while dry season and late flood season flows decrease by (-6%). The result for the Land use change scenario by replacing the wetland and swamps located at the Baro-Akobo-Sobat basin with irrigated croplands lead to the following:- 1)The change in precipitation between the current land use conditions and the proposed scenario is estimated as (~+0.5%). 2)The temperature will increase during the dry months by (~+0.4 to ~2.5) while the temperature will decrees during the wet season by around (~-0.5 to -2.0); 2)Decrease in the evapo-transpiration rate by (-8.7) during the wet months and increase in the daily evapo-transpiration rates during the dry months by (+ 1.9 ); 3)The change in the annul flow is estimate as (+6%). |