Estimating flood quantiles in southwestern part of Saudi Arabia
Ishaq, A.M.a 
,
Saada, N.M.a d
,
Allayla, R.I.a ,
Sheikh,
A.K.b
,Hussain,
T.c
a Department of Civil Engineering
b Department of Mechanical Engineering
c Research Institute, King Fahd University of Petroleum and
Minerals, Dhahran 31261, Saudi Arabia
d Colorado State University, Fort Collins, CO, United States
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Abstract
Estimating
flood quantiles is an important requirement in the
proper management of water resources in any country. In this study, regional
regression analysis is performed for the purposes of estimating flood quantiles in some of the watersheds located in the western
and southwestern parts of Saudi
Arabia. The Generalized Least Square approach as
opposed to the widely-used Ordinary
Least Square approach is used in the regression
analysis. The dependent variables of the regression analysis are the quantiles predicted by the Log Pearson Type III model and
the independent variables are the physiographic variables such as area, main
channel length, main channel slope, and watershed average slope. In contrast to
the usual watershed physiographic variables, the watershed response time
measured as time-to-peak of the flood stage curve and watershed order number
are also used to predict the flood quantiles. Results
show that the watershed response time measured as the watershed time-to-peak
and the watershed order number are significant parameters in predicting flood quantiles in Saudi Arabia.
