Elfeki, A.M.M., Hatem A Ewea, Jarbou A Bahrawi, Nassir S Al-Amri: A Convection-Decay Model for Simulating the Transmission of Flood Waves in Ephemeral Channels in Arid Zones (2014). 6 International Conference on Water Resources and th Arid Environments (ICWRAE 6): 328-333, 16-17 December, 2014, Riyadh, Saudi Arabia.

1. 7/3/2016
Dept. of Hydrology and Water Resources Management ,Faculty of
Meteorology, Environment & Arid Land Agriculture, King Abdulaziz
University , P.O. Box 80208 Jeddah 21589 Saudi Arabia
* Faculty of Engineering Mansoura Universirty
Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri
(ICWRAE 2014)
Authors:
Amro M.M. Elfeki*, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri
Presenter: Mohammed Farran

2.  Problem Statement.
 Research Objective.
 Study Area.
 Field Observations and Measurements.
 Conceptual Model.
 Model Development and Parameter Estimation
 Results
 Conclusions
7/3/2016
Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE
2014)

3. o In the literature, researchers
usually use three parameter
Muskingum method for river
flood routing with lateral
inflow (O'Donnell, T. (1985).
o Recently the method has been
applied on ephemeral
channels to incorporate
transmission losses with
success by Elfeki, et al. (2014).
o The Muskingum method
relies on three parameters.
The fitting procedure of these
parameters can led to
unphysical values.
7/3/2016
Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri
(ICWRAE 2014)

4. Development of a convection-decay model for
simulating the transmission of flood waves in
ephemeral channels.
The model has two merits:
1. Depends on two parameters not three like in
Muskingum method.
2. The parameters have physical interpretation.
7/3/2016
Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri
(ICWRAE 2014)

5. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)
Yiba basin is
located in
Makkah Al-
Mukaramah
region, in the
southwestern
part of Saudi
Arabia.
It has an
area of 2346
km2 and
drains its
water
towards the
Red Sea.

6. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

7. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)
Station
Area
(km2)
Length of
the main
stream
(km)
Basin
Slope
(m/m)
Channel
reach
length (km)
422 306.01 23.3 0.3322
10.5
401 764.96 35.07 0.2833
423 612.83 36.2 0.2657
32.2
424 2346.27 51.8 0.1969

8. v is the flood wave velocity,
Q is the discharge hydrograph,
α is the decay coefficient, and
x and t are the space and time variables
7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

9. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

10. 7/3/2016
Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE
2014)

11. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

12. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

13. 7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)

14. Based on the proposed model,
The average flood wave speed:
Reach 422-401 is 10 km/hr
Reach 423-424 is 7.4 km/hr
The average decay factor:
Reach 422-401 is 0.78 hr-1
Reach 423-424 is 0.26 hr-1
Both reaches show good agreement in terms of flood
attenuation, while for reach 423-424 there is an early arrival of
the flood wave that need further investigation.
The model in some sense is capable of simulating flood wave
movement in ephemeral streams.
7/3/2016 Amro M.M. Elfeki, Hatem A. Ewea, Jarbou A. Bahrawi and Nassir S. Al-Amri (ICWRAE 2014)