Geology topics

Warren A. Gebert

Publications and source records attributed to Warren A. Gebert.

11 recordsLinked to original sources

USGS2016

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

Streamflow characteristics were determined for 15 longterm streamflow-gaging stations for the periods 1915–2008, 1915–68, and 1969–2008 to identify trends. Stations selected represent flow characteristics for the major river basins in Wisconsin. Trends were statistically significant at the 95 percent confidence level at 13 of the 15 streamflow-gaging stations for various streamflow characteristics for 1915–2008. Most trends indicated increases in low flows for streams with agriculture as the dominant land use. The three most important findings are: increases in low flows and average flows in agricultural watersheds, decreases in flood peak discharge for many streams in both agricultural and forested watersheds, and climatic change occurred with increasing annual precipitation and changes in monthly occurrence of precipitation. When the 1915–68 period is compared to the 1969–2008 period, the annual 7-day low flow increased an average of 60 percent for nine streams in agricultural areas as compared to a 15 percent increase for the five forested streams. Average annual flow for the same periods increased 23 percent for the agriculture streams and 0.6 percent for the forested streams. The annual flood peak discharge for the same periods decreased 15 percent for agriculture streams and 8 percent for forested streams. The largest increase in the annual 7-day low flow was 117 percent, the largest increase in annual average flow was 41 percent, and the largest decrease in annual peak discharge was 51 percent. The trends in streamflow characteristics affect frequency characteristics, which are used for a variety of design and compliance purposes. The frequencies for the 1969–2008 period were compared to frequencies for the 1915–68 period. The 7-day, 10-year (Q7, 10) low flow increased 91 percent for nine agricultural streams, while the five forested streams had an increase of 18 percent. The 100-year flood peak discharge decreased an average of 15 percent for streams in the agriculture area and 27 percent for streams in the forested area. Increases in low flow for agriculture streams are attributed to changes in agricultural practices and land use as well as increased precipitation. The decrease in annual flood peak discharge with increased annual precipitation is less clear, but is attributed to increased infiltration from changes in agricultural practices and climatic changes. For future low-flow studies, the 1969–2008 period should be used to determine low-flow characteristics since it represents current (2014) conditions and was generally free of significant trends.

Wisconsin↗

USGS2012

Evaluation of the effects of Middleton's stormwater-management activities on streamflow and water-quality characteristics of Pheasant Branch, Dane County, Wisconsin 1975-2008

Few long-term data sets are available for evaluating the effects of urban stormwater-management practices. Over 30 years of data are available for evaluating the effectiveness of such practices by the city of Middleton, Wis. Analysis of streamflow and water-quality data collected on Pheasant Branch, demonstrates the relation between the changes in the watershed to the structural and nonstructural best management practices put in place during 1975-2008. A comparison of the data from Pheasant Branch with streamflow and water-quality data (suspended sediment and total phosphorus) collected at other nearby streams was made to assist in the determination of the possible causes of the changes in Pheasant Branch. Based on 34 years of streamflow data collected at the Pheasant Branch at Middleton streamflow-gaging station, flood peak discharges increased 37 percent for the 2-year flood and 83 percent for the 100-year flood. A comparison of data for the same period from an adjacent rural stream, Black Earth at Black Earth had a 43 percent increase in the 2-year flood peak discharge and a 140-percent increase in the 100-year flood peak discharge. Because the flood peak discharges on Pheasant Branch have not increased as much as Black Earth Creek it appears that the stormwater management practices have been successful in mitigating the effects of urbanization. Generally urbanization results in increased flood peak discharges. The overall increase in flood peak discharges seen in both streams probably is the result of the substantial increase in precipitation during the study period. Average annual runoff in Pheasant Branch has also been increasing due to increasing average annual precipitation and urbanization. The stormwater-management practices in Middleton have been successful in decreasing the suspended-sediment and total phosphorus loads to Lake Mendota from the Pheasant Branch watershed. These loads decreased in spite of increased annual runoff and flood peaks, which are often expected to produce higher sediment and phosphorus loads. The biggest decreases in sediment and phosphorus loads occurred after 2001 when a large detention pond, the Confluence Pond, began operation. Since 2001, the annual suspended-sediment load has decreased from 2,650 tons per year to 1,450 tons per year for a 45-percent decrease. The annual total phosphorus load has decreased from 12,200 pounds per year to 6,300 pounds per year for a 48-percent decrease. A comparison of Pheasant Branch at Middleton with two other streams, Spring Harbor Storm Sewer and Yahara River at Windsor, that drain into Lake Mendota shows that suspended-sediment and total phosphorus load decreases were greatest at Pheasant Branch at Middleton. Prior to the construction of the Confluence Pond, annual suspended-sediment yield and total phosphorus yield from Pheasant Branch watershed was the largest of the three watersheds. After 2001, suspended-sediment yield was greatest at Spring Harbor Storm Sewer, and lowest at Yahara at Windsor; annual total phosphorus yield was greater at Yahara River at Windsor than that of Pheasant Branch. The stormwater-quality plan for Middleton shows that the city has met the present State of Wisconsin Administrative Code chap. NR216/NR151 requirements of reducing total suspended solids by 20 percent for the developed area in Middleton. In addition, the city already has met the 40-percent reduction in total suspended solids required by 2013. Snow and ice melt runoff from road surfaces and parking lots following winter storms can effect water quality because the runoff contains varying amounts of road salt. To evaluate the effect of road deicing on stream water quality in Pheasant Branch, specific conductance and chloride were monitored during two winter seasons. The maximum estimated concentration of chloride during the monitoring period was 931 milligrams per liter, which exceeded the U.S. Environmental Protection Agency acute criterion of 860 milligrams per liter. Chloride concentrations exceeded the U.S. Environmental Protection Agency chronic criterion of 230 milligrams per liter for at least 10 days during February and March 2007 and for 45 days during the 2007-8 winter seasons. The total sodium chloride load for the monitoring period was 1,720 tons and the largest sodium chloride load occurred in March and April of each year.

Wisconsin↗

USGS2011

Groundwater recharge in Wisconsin— Annual estimates for 1970–99 using streamflow data

The groundwater component of streamflow is important because it is indicative of the sustained flow of a stream during dry periods, is often of better quality, and has a smaller range of temperatures, than surface contributions to streamflow. All three of these characteristics are important to the health of aquatic life in a stream. If recharge to the aquifers is to be preserved or enhanced, it is important to understand the present partitioning of total streamflow into base flow and stormflow. Additionally, an estimate of groundwater recharge is important for understanding the flows within a groundwater system-information important for water availability/sustainability or other assessments. The U.S. Geological Survey operates numerous continuous-record streamflow-gaging stations (Hirsch and Norris, 2001), which can be used to provide estimates of average annual base flow. In addition to these continuous record sites, Gebert and others (2007) showed that having a few streamflow measurements in a basin can appreciably reduce the error in a base-flow estimate for that basin. Therefore, in addition to the continuous-record gaging stations, a substantial number of low-flow partial-record sites (6 to 15 discharge measurements) and miscellaneous-measurement sites (1 to 3 discharge measurements) that were operated during 1964-90 throughout the State were included in this work to provide additional insight into spatial distribution of annual base flow and, in turn, groundwater recharge.

Wisconsin↗

USGS2011

Estimating 1970-99 average annual groundwater recharge in Wisconsin using streamflow data

Average annual recharge in Wisconsin for the period 1970-99 was estimated using streamflow data from U.S. Geological Survey continuous-record streamflow-gaging stations and partial-record sites. Partial-record sites have discharge measurements collected during low-flow conditions. The average annual base flow of a stream divided by the drainage area is a good approximation of the recharge rate; therefore, once average annual base flow is determined recharge can be calculated. Estimates of recharge for nearly 72 percent of the surface area of the State are provided. The results illustrate substantial spatial variability of recharge across the State, ranging from less than 1 inch to more than 12 inches per year. The average basin size for partial-record sites (50 square miles) was less than the average basin size for the gaging stations (305 square miles). Including results for smaller basins reveals a spatial variability that otherwise would be smoothed out using only estimates for larger basins. An error analysis indicates that the techniques used provide base flow estimates with standard errors ranging from 5.4 to 14 percent.

Wisconsin↗

USGS2007

Relationship between annual runoff and watershed area for the eastern United States

As part of the U.S. Environmental Protection Agency's effort to determine the long-term effects of acidic deposition on surface water chemistry, annual runoff was estimated for about 1000 ungaged sites in the eastern U.S. using runoff contour maps. One concern in using contour maps was that a bias may be introduced in the runoff estimates due to the size of the 1000 ungaged sites relative to the size of the watersheds used in developing the maps. To determine if a bias was present the relationship between the annual runoff (expressed as depth) and the watershed area for the Northeast (NE) and Southern Blue Ridge Province (SBRP) was tested using five regional data bases. One short-term data base (1984 Water Year, n = 531) and two long-term data bases (1940–57, n = 134 and 1951–80, n = 342) were used in the NE. In the SBRP one short-term database (1984 Water Year, n = 531) and one long-term data base (1951–80, n = 60) were used. For the NE and the SBRP, runoff was not directly correlated with watershed area using the five regional databases. Also, runoff normalized by precipitation was not related to watershed area.

northeastern United States↗

USGS1996

Real-time streamflow conditions

Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 stream-gaging stations located throughout Wisconsin can be viewed by accessing the Wisconsin District Home Page at: http://wwwdwimdn.er.usgs.gov

Wisconsin↗

USGS1992

Flood-frequency characteristics of Wisconsin streams

Flood-frequency characteristics for 269 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years. Annual flood peaks for the period of record for each gaged site are included. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of these equations. The State was divided into five areas of similar physiographic characteristics. The most significant basin characteristics are drainage areas, main-channel slope, soil permeability, storage, rainfall intensity, and forest cover. The standard error of prediction for the equation for the 100-year flood discharge ranges from 25 to 33 percent in the State. A comparison of multiple-regression analyses by use of generalized least squares and ordinary least squares was made to determine the best method for analysis. A split-sampling technique was used for all the stations in the State. Differences in results of the two methods were minimal. The generalized least-squares method was chosen for use because its theoretical basis is superior to that of ordinary least squares and its estimates of accuracy of the equations for estimating flood-frequency characteristics at ungaged sites is better than that of ordinary least squares. A method for estimating flood-frequency characteristics of regulated streams was developed from the relation of discharge and drainage area. Graphs for the major regulated streams are presented in the report. Drainage-basin characteristics derived from satellite imagery and channel morphology data were tried in the regression equations but did not improve their accuracy.

Wisconsin↗

USGS1990

Map of mean annual runoff for the Northeastern, Southeastern, and Mid-Atlantic United States, water years 1951-80

A map of mean annual runoff for States within the Northeastern, Southeastern, and Mid-Atlantic United States was prepared by the U.S. Geological Survey for the Direct/Delayed Response Project being conducted by the U.S. Environmental Protection Agency. This map shows mean annual runoff during water years 1951-80. Mean annual runoff from the northeastern region during 1951-80 ranged from less than 12 to greater than 40 inches. Runoff from the southeastern region runoff ranged from less than 12 to greater than 55 inches. In the mid-Atlantic region ranged from less than 10 to greater than 40 inches. Error analysis using 93 gaging stations not used for preparing the runoff map showed that the runoff map could be used to predict runoff with an average error of less than 10%. Errors in runoff estimation averaged about 12% if the locations of the gaging stations were used to estimate runoff instead of computing an area-weighted average over the basin. If the locations of the gaging stations were used to estimate runoff, there also was a significant negative bias of the errors that did not occur if the centroid or a weighted average runoff of the drainage basin were used. The runoff map is expected to be more accurate in areas that have a relatively high concentration of gaging stations and little topographic variability, such as part of the Northeast. Based on these criteria, the least reliably mapped areas would be in the Smokey Mountains along the North Carolina- Tennessee border.

Water-Resources Investigations Report↗

USGS1980

Low-flow characteristics of streams in the upper Wisconsin River basin, Wisconsin

Low-flow characteristics of streams in the upper Wisconsin River basin are presented. Included are estimates of low-flow frequency at 10 gaging stations, flow duration at 8 gaging stations, and low-flow frequency characteristics at 13 low-flow partial-record stations and 81 miscellaneous sites. Equations are provided to estimate low-flow characteristics at ungaged sites and at sites where one base-flow discharge measurement is available. The equations were determined from multiple-regression analyses that related low-flow characteristics at gaging stations and low-flow partial-record stations to basin characteristics. The standard error of estimate is provided for each method of estimating the annual minimum 7-day mean flow below which the flow will fall on the average of once in 2 years and once in 10 years. The standard error of estimate for the 7-day 10-year low flow ranged from 9% to 113% depending on the type of data available. Standard error provides the user with the expected degree of accuracy for each method. (USGS)

Wisconsin↗

USGS1971

Hydrology of Pine Creek, Wisconsin

The purpose of this study was to determine the hydrologic characteristics of Pine Creek, Price County, Wisconsin, in order to evaluate a proposed reservoir on Pine Creek. The streamflow characteristics estimated are the mean flows, low flows, and flood peaks. The study was done by the U.S. Geological Survey in cooperation with the Wisconsin Department of Natural Resources.

Wisconsin↗

USGS1971

Hulburt Creek Hydrology, Southwestern Wisconsin

The purpose of this study was to determine the hydrologic characteristics of Hulburt Creek, Sauk County, Wis., in order to evaluate a proposed reservoir. The streamflow characteristics estimated are the low flow, monthly flow, and inflow flood. The study was done by the U.S. Geological Survey in cooperation with the Wisconsin Department of Natural Resources. The following estimates are for the point on Hulburt Creek at the proposed Dell Lake damsite near Wisconsin Dells. The drainage area is 11.2 square miles.

Open-File Report↗