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Clayton H. Hardison

Publications and source records attributed to Clayton H. Hardison.

6 recordsLinked to original sources
USGS1976

Confidence limits for flood-frequency curves computed from samples from Pearson type III populations

A study of T -year events computed from samples drawn from Pearson type III populations of known skew indicates that for skew coefficients between -1.0 and 1.0, confidence limits can be derived from the confidence limits computed for frequency curves based on samples from normal distributions. For samples from populations with skew coefficients between -0.5 and 0.5, the ratios of the standard deviates of the confidence limits to the standard deviates of the underlying frequency curve are approximately the same as for samples from normal distributions. A table provides adjustments required to make the ratios for normal distributions more applicable to distributions with skews in the range -1.0 to 1.0.

Journal of Research of the U.S. Geological Survey↗
USGS1976

Interstation correlation of peak-flow estimates

Equations are given for using the correlation coefficient between annual peaks at a pair of stream gaging stations to estimate the interstation correlation coefficient of estimated T -year peaks, computed standard deviations, and computed skew coefficients at the same pair of stations. The equations are based on statistics computed from samples of annual peaks simulated from normal distributions with built-in interstation correlation. The interstation correlation of 50- year peaks was found to be about equal to the square of the interstation correlation coefficient of the annual peaks.

Journal of Research of the U.S. Geological Survey↗
USGS1963

Low-flow frequency curves for selected long-term stream gaging stations in eastern United States

Curves showing the magnitude and frequency of annual low flow at 85 streamgaging stations located in 17 States east and 5 States west of the Mississippi River have been smoothed and adjusted to one of four long-term periods. They are presented to show the similarity and dissimilarity of curves even in the same State and to provide background information for studies of the statistical properties of low-flow frequency curves and for studies of the relation between hydrologic environment and low flow. The results are presented as greatly reduced graphs to facilitate comparison and are summarized in tables from which expanded graphs can be plotted.

Water Supply Paper↗
USGS1960

Double-mass curves, with a section fitting curves to cyclic data

The double.-mass curve is used to check the consistency of many kinds of hydrologic data by comparing data for a single station with that of a pattern composed of the data from several other stations in the area The double-mass curve can be used to adjust inconsistent precipitation data. The graph of the cumulative data of one variable versus the cumulative data of a related variable is a straight line so long as the relation between the variables is a fixed ratio. Breaks in the double-mass curve of such variables are caused by changes in the relation between the variables. These changes may be due to changes in the method of data collection or to physical changes that affect the relation. Applications of the double-mass curve to precipitation, streamflow, and sediment data, and to precipitation-runoff relations are described. A statistical test for significance of an apparent break in the slope of the double-mass curve is described by an example. Poor correlation between the variables can prevent detection of inconsistencies in a record, but an increase in the length of record tends to offset the effect of poor correlation. The residual-mass curve, which is a modification of the double-mass curve, magnifies imperceptible breaks in the double-mass curve for detailed study. Of the several methods of fitting a smooth curve to cyclic or periodic data, the moving-arc method and the double-integration method deserve greater use in hydrology. Both methods are described in this manual. The moving-arc method has general applicability, and the double integration method is useful in fitting a curve to cycles of sinusoidal form.

Water Supply Paper↗