Statistical–Dynamical Approach for Streamflow Modeling at Malakal, Sudan, on the White Nile River
Publication: Journal of Hydrologic Engineering
Volume 14, Issue 2
Abstract
The upper White Nile Basin above Malakal, Sudan, is considered to be one of the most complicated and diverse hydrologic settings on Earth. Accurately depicting and predicting the streamflow at Malakal is essential for water managers considering Nile Basin-wide initiatives and potential large-scale projects. Dynamical, statistical, and combination models are assessed for their ability to predict monthly streamflow at Malakal. The dynamical model represents a lumped parameter, average-monthly water balance, whereas the statistical model incorporates a nonparametric approach based on local polynomial regression, utilizing principal components of precipitation and temperature. The combination of dynamical and statistical models through linear regression produces model weights of 0.44 and 0.59, respectively, implying a relatively balanced influence. Evaluation of the combination model demonstrates significant overall skill (correlation coefficients equal to 0.83), outperforming either individual model for the validation periods selected. Peak streamflow analyses of timing and quantity also exhibit superior performance by the combination model. An ensemble approach, practical for planning and management from a probabilistic standpoint, is additionally demonstrated.
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Acknowledgments
This research study was partially funded by a grant from the U.S. Agency for International Development (USAID) through the International Food Policy Research Institute (IFPRI), and forms part of the first writer’s Ph.D. dissertation at the University of Colorado—Boulder. The writers wish to express their appreciation to the editors and three anonymous reviewers for their insightful comments and suggestions, undeniably improving the quality of this paper.
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Information & Authors
Information
Published In
Journal of Hydrologic Engineering
Volume 14 • Issue 2 • February 2009
Pages: 185 - 196
Copyright
© 2009 ASCE.
History
Received: May 31, 2007
Accepted: Apr 28, 2008
Published online: Feb 1, 2009
Published in print: Feb 2009
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