الفهرس 
LITERATURE REVI EWOnly 14 pages are availabe for public view
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Abstract
During the last decades to centuries human activities have considerably changed the
Earth’s surface vegetation cover. So researches on the influence of land processes on
climate and the study of the climate effects of land cover change in order to bcucr
understand the influence of human activities on climate and the environment becomes
very important in both science and social life. The study of the climate effects of land
use change over Nile Sub-Basin is important for a better understanding of both
present climate and projections of future climate change. It is also of particular
concern for the effective utilization of natural and climate resources and the
sustainable development of economy and society in the region.
As a mailer of fact the impact of land lise I vegetation cover change on climate IS 110\\
an important topic with the global change debate. In recent years increasing research
effons have been devoted to the study of the climatic impacts of land use change over
many regions. While much was learnt from previous works, important limitations
were due to the model used and the availability of computer resources. For example,
the GCMs employed in such previous studies used a coarse horizontal resolution
which performed poorly in simulating regional climate over the Nile Basin. which is
mostly dominated by the development of monsoon phenomena. Higher resolution
RCM simulations were carried out, but the duration of the integrations IVa relatively
shon (several months to a few years) which restricts the rchabiliry-of the rudies
within the context of ”climatological effects”. Funher research on this topic is thus
needed using high resolution model for long simulation times and this is now feasible
because of the rapid development of models and computer power.
Many researchers have attempted to address the impact of future climate change on
ile flows. using GCMs for a large set of SRES emissions scenarios (Conway, 2000.
Elshamy, 2008); however few studies use models capable of simulating key
characteristics of the Nile. Sayed (2003) recommends that effort be devoted to
calibration of one or more regional climate models (RCMs) over the region, followed
by linkage of the RCM(s) with a hydrologic simulation model. Such an effon should
improve studies of climate impacts by a) increasing the accuracy of precipitation and
runoff estimates obtained from climate models, and b) enabling more complete
consideration of local climate features that arc poorly represented in GCMs.Mohamed et al. (2005) presented results of thc first regional climatic-hydrologic
model (MCMO) applied to the Nile Basin. In this model, interactions between
climatic and hydrological processes on thc land surface were fully coupled for the
first time. Given the extremely low runoff coefficients in the catchment, the results
obtained were considered satisfactory. Nonetheless, the study claimed to validate the
RACMO model for the whole of the Nile using observational data from only two
stations. In addition, the model does not appear to be currently operational [Yo
Mohamed, personal communication, 2006].
The objective of this study is to demonstrate an application Regional Climate Model
(RegCM3) using different scenarios of land use under the current climate as well as
future emission scenarios over Baro-Akobo-Sobat Sub-basin. Then use the climate
parameters -rainfall estimates, evaporation- to feed the ile Forecast System (NFS), a
gridded conceptual, fine-scale hydrological model of the Nilc Basin housed at the
ile Forecast Center of the Ministry of Water Resources and Irrigation in Egypt.
Using the NFS, the author is able to quantify the impact of perturbations related to
one of the climate change scenario on stream flows. This research will be useful for
improving current understanding of climate change impacts on the hydrology of the
Nile Basin, due to the finer spatial resolution and greater ability of RCMs to link
changes in precipitation, temperature, and land use.
In this research, the author presents an analysis of the climate effe~ts of land use
change in one of the Nile sub-basins based on two relatively long (25years) regional
model (RegCM3) simulations. A two different vegetation cover darascts are
employed, one representing the current land lISC and the other representing the
potential vegetation cover results from human intervention. The possible effects and
feedback induced by anthropogenic land use change on thc climate of Baro-Akobo
arc analyzed based on ’he differences in various simulated climatic variables between
rhc two simulations.