Low-flow characteristics of Kentucky streams

Low-flow characteristics were determined for 136 continuous-record and 212 low-flow partial-record streamflow gaging stations in Kentucky. Low-flow frequency curves were developed for the continuous-record gaging stations from daily mean streamflows for unregulated periods of 10 years or more. Through graphical correlation with data from one or more of the continuous-record stations, estimates of selected low-flow frequency values were also made at each of the partial-record stations. Techniques are presented to estimate the 7-day 2-year and 7-day 10-year low-flow frequency values for ungaged, unregulated streams in Kentucky. These frequency values were determined at each of the continuous-record gaging stations and were related to basin characteristics and streamflow indices using multiple linear regression. The most significant variables for estimating the 7-day 2-and 10-year low-flow values from the analysis were drainage area and streamflow-variability index. The equations developed to estimate the 7-day 2-year and the 7-day 10-year low flows have a standard error of estimate of 71 and 90 percent, respectively.