Low-flow characteristics of streams in the Lake Michigan basin, Wisconsin

Abstract

Introduction Basin description Low-flow characteristics Analytical techniques Gaging stations Low-flow partial-record stations Miscellaneous sites Accuracy Gaging stations Low-flow partial-record stations Miscellaneous sites Estimating low-flow characteristics at ungaged sites Streamflow characteristics Basin characteristics Regression analysis Sites without base-flow data Sites with some base-flow data Verification of regression equations that use base-flow index Application of estimating procedures Sites without base-flow data Sites with some base-flow data Comparison of methods Summary . References ILLUSTRATIONS IV EXPLANATION OF TERMSBase flow That part of the streamflow derived from ground water.Low flow The minimum stream discharge that occurs within a given time period.Continuous-record gaging station A station where continuous streamflow data are collected.Low-flow partial-record station A station where eight or more baseflow discharge measurements are made in at least a 2-year period to determine low-flow characteristics.Miscellaneous site A site where less than eight base-flow discharge measurements have been made as part of other water-resources investigations or to determine the stream* s base-flow characteristics for this report.annual minimum 7-day mean flow below which the flow will fall on the average of once in 2 years. Q7 10 The annual minimum 7-day mean flow below which the flow will fall on the average of once in 10 years.Q90 The discharge at the 90 percent flow-duration point which is defined as the discharge that is exceeded 90 percent of the time.Standard error of estimate (SE) Is a range such that values estimated by a method are within this range at about 67 percent of the sites.SEy 2 The standard error of estimate for the Qy 2 discharge. SE7,10 T^e standard error of estimate for the Qy^io discharge.

Use of Streamflow Data to Estimate Base Flow/Ground‐Water Recharge For Wisconsin1

“…Previous low‐flow studies used multiple regression analysis to develop relationships between low‐flow characteristics and drainage basin characteristics (Gebert and Holmstrom, 1977; Gebert, 1978, 1979a,b, 1980, 1982; Holmstrom, 1978, 1979, 1980a,b, 1982; Stedfast, 1979). The basin characteristics used in this analysis are the ones that were found most important in the low‐flow studies.…”

Changes in streamflow characteristics in Wisconsin as related to precipitation and land use

“…Most of the streamflow data used in those reports were for the entire period of data at a streamflow-gaging station through the mid-1970s depending upon when the report was prepared; therefore, the low-flow characteristics in table 3 for the 1915-68 period are fairly representative of those published in these low-flow reports. A comparison of the Q 7, 10 discharges between the report values (Holmstrom, 1980a(Holmstrom, , 1980b(Holmstrom, , 1982Stedfast, 1979) and the values for the 1915-68 period showed the average difference is less than 5 percent.…”

“…A comparison was made with low-flow characteristics that were previously computed for the Wisconsin River basins in the 1970s and 1980s for the design of sewage-treatment plants and industrial outfalls (Gebert and Holmstrom, 1977;Gebert, 1978Gebert, , 1979aGebert, , 1979bGebert, , 1980Gebert, , 1982Holmstrom, 1978Holmstrom, , 1979aHolmstrom, , 1979bHolmstrom, , 1980aHolmstrom, , 1980bHolmstrom, , 1982Stedfast, 1979). Most of the streamflow data used in those reports were for the entire period of data at a streamflow-gaging station through the mid-1970s depending upon when the report was prepared; therefore, the low-flow characteristics in table 3 for the 1915-68 period are fairly representative of those published in these low-flow reports.…”