Use of the Lorenz Curve to Quantify Statistical Nonuniformity of Sediment Transport Rate
Publication: Journal of Hydraulic Engineering
Volume 135, Issue 4
Abstract
The Lorenz curve and the Gini index are statistical tools that have been widely used to quantify nonuniformity in economics, ecology, and medicine, but have apparently not been previously applied in hydraulic engineering. In this work, the Lorenz curve was applied to the analysis of sediment transport data from several experiments with natural and lightweight solid particles. The distributions of instantaneous sediment transport rate data have been analyzed, leading to some interesting observations: (1) the values are quite nonuniformly distributed, with a significant proportion of zero values at the lowest sediment transport rates; and (2) the distributions of the values considering only samples with nonzero values are still quite nonuniform; yet the variability of the Gini index with the average sediment transport rate is much smaller than that obtained for the complete data samples, indicating a major role of intermittency in determining the nonuniformity of sediment transport.
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Acknowledgments
This work was funded by the Italian Ministry of University and Research under the “MOMICS” project. The writer is grateful to Francesco Ballio and Alessandra Mori for the useful discussions and suggestions that gave impulse to the manuscript. Comments and suggestions made by three reviewers and the editors allowed for considerable improvement of the original version of the manuscript.
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Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 135 • Issue 4 • April 2009
Pages: 320 - 326
Copyright
© 2009 ASCE.
History
Received: Sep 19, 2007
Accepted: Oct 17, 2008
Published online: Apr 1, 2009
Published in print: Apr 2009
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