Low-flow characteristics of streams in the Lake Superior Basin, Wisconsin

Abstract

The purpose of this report is to describe low-flow characteristics of streams in the Lake Superior where streamflow data have collected and to present equations for estimating low-flow characteristics at ungaged sites. Included are estimates of low-flow frequency and flow duration at 9 gaging stations, and low-flow frequency characteristics at l6 low-flow partial-record stations and 119 miscellaneous sites. Six equations are provided to estimate low-flow characteristics at ungaged sites and at sites where one discharge measurement is available. The relationships were determined from multiple-regression analyses that related the low-flow characteristics at gaging stations and low-flow partial-record stations to basin characteristics. Drainage area (A) and drift thickness (H) were the most significant characteristics in explaining the variations in low flow for ungaged sites. The equations and standard error of estimates (SE) for ungaged sites are: o 2 -r.w^-uw A H SE = 99 percent = 6.rxiO~TA1 * 2TH2 ' 21 SE = 131 percent 9 15 For sites where one base-flow measurement has been made drainage area (A), basin storage (Bs), transmitsivity (T), and base-flow index (Bf) were the most significant characteristics. The equations and standard error of estimate are: 0 Q2k 0 113 0 Q2Q . * 1! *Xf' y * SEV _ = 39 percent f »^I » < Q7 = O.U89A1 25Bs~°' 1|35Bf1 03 SEV _ n = 65 percent I j-LU ( i-LU Low-flow characteristics estimated for the Lake Superior basin have a moderately high standard error of estimate when compared with other basins in Wisconsin. This reflects the large variability of low flow for streams in the Lake Superior basin which is due to the large variation in geologic or aquifer characteristics that provide ground-water inflow for the streams, WISCONSIN 20 40 60 Kilometers ST. CR01X RIVER BASIN UPPER WISCONSIN RIVER BASIN MENOMINEE OCONTOPESHTIG RIVER BASIN CHIPPEWA RIVER BASIN CENTRAL WISCONSIN RIVER BASIN FOX-WOLF RIVER BASIN TREMPEALEAUBLACK RIVER BASIN LOWER WISCONSIN RIVER BASIN WRI77-118 ROCK-FOX RIVER BASIN PECATONICASUGAR RIVER BASIN Note: WRI numbers indicate reports previously published Figure 1. Location of the Lake Superior basin in Wisconsin.