On the probability distribution of daily streamflow in the United States

Hydrology and Earth System Sciences
By: , and 



Daily streamflows are often represented by flow duration curves (FDCs), which illustrate the frequency with which flows are equaled or exceeded. FDCs have had broad applications across both operational and research hydrology for decades; however, modeling FDCs has proven elusive. Daily streamflow is a complex time series with flow values ranging over many orders of magnitude. The identification of a probability distribution that can approximate daily streamflow would improve understanding of the behavior of daily flows and the ability to estimate FDCs at ungaged river locations. Comparisons of modeled and empirical FDCs at nearly 400 unregulated, perennial streams illustrate that the four-parameter kappa distribution provides a very good representation of daily streamflow across the majority of physiographic regions in the conterminous United States (US). Further, for some regions of the US, the three-parameter generalized Pareto and lognormal distributions also provide a good approximation to FDCs. Similar results are found for the period of record FDCs, representing the long-term hydrologic regime at a site, and median annual FDCs, representing the behavior of flows in a typical year.

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Publication type Article
Publication Subtype Journal Article
Title On the probability distribution of daily streamflow in the United States
Series title Hydrology and Earth System Sciences
DOI 10.5194/hess-21-3093-2017
Volume 21
Issue 6
Year Published 2017
Language English
Publisher European Geosciences Union
Contributing office(s) National Research Program - Eastern Branch
Description 11 p.
First page 3093
Last page 3103
Country United States
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