الفهرس 
THE MONITORING, FORECASTING AND SIMULATION SYSTEM OF THE NILE RIVEROnly 14 pages are availabe for public view
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Abstract
the Monitoring, Forecasting and Simulation project (MFS) was initiated in 1990 by the
Minis. J of Public Works and Water Resources (MPWWR) for the purpose of providing
planners and decision makers in Egypt with (a) Timely forecasts ofthe Nile River inflows into
the High Aswan Darn (HAD) reservoir, (b) Real-time information about hydrological and
meteorological processes occurring in the whole Nile Basin, and (c) Tools to simulate flow
regime of the Nile and assess the possible consequences of changes, man-induced or natural, in
the Basin.
The simulation component of the MFS system is a distributed model with the sub-basin
represented as connected grid points. Connectivity of the grid points was determined by a
software which uses Geographic Information System (GIS) based on streams network definition
and elevations. TI,e runoff simulation model has 3 parts: a water balance model which produces
surface subsurface runoff; a hiUslope routing model to route surface runoff within the cell to the
stream, and a channel routing model for moving water from grid cell to grid cell (i.e. the stream
channel network). The channel routing model has 5 parameters: the channel friction slope (s),
the Manning’s roughness coefficient (n), the channel length (L), and the parameters (a and b)
which depend on channel shape. The study presents the folJowing:(a) an approach to estimate
parameters a and b at Khartoum location using available data for this cross section. Then, the GIS
(geographic information system) is employed to set the value of parameter ”a” at each grid cell
as a function of the catchment area of each sub-basin in order to have cross section for the
channel close to the real cross section, (b) a sensitivity analysis for the channel roughness
coefficient at Diem station with the new cross section parameters, (c) parameter optimization for
the Manning’s roughness coefficient(n) based on the new parameters of the cross section (a.b),
(d) a comparison of MFS simulation with new simulation.
The Extended Stream flow Predictions (ESP) is employed to simulate the future based
on historical rainfall patterns and current watershed conditions to produce forecasting. Besides,
the study compares the MFS forecasting with a simpler statistical model to check and validate
the behavior of tile forecasting system.
TI,e study shows that tbe distributed parameters for the channel cross section gives better
simulation results than the lumped parameter. It shows also that the best results can be achieved with the case of triangular section. The sensitivity analysis shows that the simulated hydrograph
for the case of triangular section is mort; sensitive to the changes in the roughness parameter than
the case of rectangular section.
The comparison between the ESP and the regression model shows that the ESP forecasts
are more reliable than the regression model forecasts. More specifically, the comparison results
indicate that the ESP is less biased and include much less uncertainties. In June and July, the ESP
forecast is overestimated indicated by positive mean error. This could be due to an error in the
initial state variable of the system or due to an error in the historical rainfall used as an input to
the ESP for these particular months. It recommended to consider both the ESP forecasts and the
regression model forecasts for June and July.