Estimating low-flow frequency for perennial Missouri Ozarks streams

A linear regression model, utilizing an independent variable described as the flow area of a stream, has been developed for use in estimating minimum streamflow at ungaged sites in the Ozarks region of Missouri. The basic premise in the method is that low-flow characteristics at any point on perennial Ozarks streams are significantly related to the average width and depth or flow area of the minimum flows.

The standard errors of regression equations defining the 7-day Q2, 7-day Q10, and 7-day Q20 are 41, 60, and 76 percent, respectively. In comparison, standard errors of 170 to 390 percent were obtained during previous regionalization studies.