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Flow-duration curves

January 1, 1994

The flow-duration curve is a cumulative frequency curve that shows the percent of time specified discharges were equaled or exceeded during a given period. It combines in one curve the flow characteristics of a stream throughout the range of discharge, without regard to the sequence of occurrence. If the period upon which the curve is based represents the long-term flow of a stream, the curve may be used to predict the distribution of future flows for water- power, water-supply, and pollution studies.

This report shows that differences in geology affect the low-flow ends of flow-duration curves of streams in adjacent basins. Thus, duration curves are useful in appraising the geologic characteristics of drainage basins.

A method for adjusting flow-duration curves of short periods to represent long-term conditions is presented. The adjustment is made by correlating the records of a short-term station with those of a long-term station.

Citation Information

Publication Year 1959
Title Flow-duration curves
DOI 10.3133/wsp1542A
Authors James Kincheon Searcy
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Water Supply Paper
Series Number 1542
Index ID wsp1542A
Record Source USGS Publications Warehouse