USGS Science⌕ Search

Geology topics

W.A. Gebert

Publications and source records attributed to W.A. Gebert.

13 recordsLinked to original sources
USGS2007

Streamflow trends in Wisconsin's driftless area

Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows.Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows.

Water Resources Bulletin↗
USGS2007

Use of streamflow data to estimate base flowground-water recharge for Wisconsin

The average annual base flow/recharge was determined for streamflow-gaging stations throughout Wisconsin by base-flow separation. A map of the State was prepared that shows the average annual base flow for the period 1970-99 for watersheds at 118 gaging stations. Trend analysis was performed on 22 of the 118 streamflow-gaging stations that had long-term records, unregulated flow, and provided aerial coverage of the State. The analysis found that a statistically significant increasing trend was occurring for watersheds where the primary land use was agriculture. Most gaging stations where the land cover was forest had no significant trend. A method to estimate the average annual base flow at ungaged sites was developed by multiple-regression analysis using basin characteristics. The equation with the lowest standard error of estimate, 9.5%, has drainage area, soil infiltration and base flow factor as independent variables. To determine the average annual base flow for smaller watersheds, estimates were made at low-flow partial-record stations in 3 of the 12 major river basins in Wisconsin. Regression equations were developed for each of the three major river basins using basin characteristics. Drainage area, soil infiltration, basin storage and base-flow factor were the independent variables in the regression equations with the lowest standard error of estimate. The standard error of estimate ranged from 17% to 52% for the three river basins. ?? 2007 American Water Resources Association.

Journal of the American Water Resources Associatio↗
USGS1989

Preparation of average annual runoff map of the United States, 1951-80

Average annual runoff was computed or estimated for 2,148 hydrologic cataloging units in the United States and Puerto Rico , for the period 1951-80. Runoff was computed from the recorded streamflow at 5,951 U.S. Geological Survey gaging stations. The runoff at more than 3,000 of these stations was estimated by correlation with other nearby stations to adjust for missing data. These runoff data were used to draw a map depicting the variation of runoff throughout the nation. Average annual runoff varied from less than 0.01 inch in parts of the Great Basin (Utah, parts of Nevada, Oregon, and California) to more than 240 inches in southeastern Alaska. (USGS)

Open-File Report↗
USGS1987

Average Annual Runoff in the United States, 1951-80

Runoff is the water in a river or stream that results from precipitation falling on the drainage basin. It is the net discharge into the stream from surface-water and ground-water sources with losses occurring from evapotranspiration and other consumptive uses. Runoff can be expressed by a variety of numerical values, but average depth of water over the drainage basin, in inches per year, probably is the most widely used unit of measurement. The map of average annual runoff (fig. 1), in inches per year, shows the geographical distribution of runoff in tributary streams for the years 1951—80; it describes the magnitudes and variations of runoff nationwide. The map was prepared to reflect the runoff of tributary streams rather than in major rivers in order to represent more accurately the local or small scale variation in runoff with precipitation and other geographical characteristics. The 1951–80 period was selected to conform to the period chosen by the World Meteorological Organization for study of climatic variations. The map should not be used to estimate the streamflow for any specific site. More detailed information for a specific area can be obtained from streamflow data collected by the U.S. Geological Survey, other Federal agencies, and State agencies.

Hydrologic Atlas↗
USGS1987

Maps of runoff in the northeastern region and the southern Blue Ridge Province of the United States during selected periods in 1983-85

Maps of annual runoff for two regions in the eastern United States were prepared by the U.S. Geological Survey for the Direct/Delayed Response Project being conducted by the U.S. EPA. These maps show annual runoff during water year 1984 in the northeastern region and in the Southern Blue Ridge Province. Runoff from the northeastern region during the 1984 water yr ranged from 12 to 55 in.; this was 25 to 55% > average runoff for the 1951-80 period. Runoff from the Southern Blue Ridge Province during the 1984 water year ranged from 14 to 60 in.; this was 10 to 30% > the average runoff for the 1951-80 period. A split sample analysis of the data for New York was conducted to evaluate the accuracy of the runoff mapping procedure used in this report. A runoff map was prepared using one-half of the data base. The map was then used to estimate runoff at the gaging stations that were not used to develop the map. The values estimated from the split-sample map were found to differ from the actual recorded values by 9.9%. The runoff maps are most accurate in areas with a relatively large concentration of gaging stations and little topographic variability. Conversely, the maps are least accurate in areas with few gaging stations and high topographic variability. Based on these criteria, those parts of the maps covering Connecticut, Massachusetts, New Jersey, and Rhode Island, are the most reliable. The least reliable parts of the maps are those along the North Carolina-Tennessee border and in parts of Maine.

Connecticut, Georgia, Maine, Massachusetts, New Ha↗
USGS1986

A history of annual streamflows from the 21 water-resource regions in the United States and Puerto Rico, 1951-83

Annual streamflows from the 21 water-resource regions in the United States and Puerto Rico were calculated for the period 1951-83. The total streamflow discharging to the oceans from the conterminous United States during this period averaged 1,270 billion gallons per day. The outflow from the Lower Mississippi Water-Resource Region (08), which drains 41 percent of the land area of the conterminous United States, contributes 34 percent of the total streamflow to the oceans, which is the most of any region. A 15-year moving average of the annual streamflow was also calculated for each region. The Mid-Atlantic (Region 02) shows a decreasing trend in streamflow since the mid-1970's whereas the Upper Mississippi (Region 07), the Missouri (Region 10), the Rio Grande (Region 13), the Upper Colorado (Region 14), the Lower Colorado (Region 15), the Great Basin (Region 16), and California (Region 18) all show an increasing trend in streamflows. Streamflow from the Upper and Lower Colorado (Regions 14 and 15) appear to be heavily affected by large storage reservoirs. Streamflow from the Upper Colorado (Region 14) shows a decreasing streamflow in 1963 and 1964, which may be due to filling of Lake Powell.

Puerto Rico↗
USGS1981

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

This report describes low-flow characteristics of streams in the central Wisconsin River basin where streamflow data have been collected and presents equations for estimating low-flow characteristics at ungaged sites. Included are estimates of low-flow frequency at 34 gaging stations, flow duration at 24 gaging stations, and low-flow frequency characteristics at 18 low-flow partial-record stations and 131 miscellaneous sites. Due to the large variability in low-flow characteristics, the central Wisconsin River basin was divided into four areas of similar geologic and topographic conditions. Separate equations are provided for each area 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 the low-flow characteristics at gaging stations and at low-flow partial-record stations to basin characteristics. Drainage area (A), hydraulic conductivity (K), soil-infiltration capacity (l), forest cover (F), base-flow index (Bf), and drift thickness (H) were the most significant characteristics in explaining the variations in low flow at ungaged sites. The standard error of estimate (SE), provided for each equation, ranged from 10 to 140 percent. Equations with the lowest SB's were for the central sand plain area that contains relatively thick sand aquifers. The highest SB's were associated with equations for the area west of the Wisconsin River where thin glacial drift with fairly low permeability overlies crystalline rock. The low-flow characteristics determined for all types of sites in the central sand plain area have the lowest SE's compared to other basins in the State. This is due to the sand deposits which yield a high and uniform base flow.

Wisconsin↗
USGS1979

Red Cedar River basin, Wisconsin: Low-flow characteristics

Low-flow characteristics in the Red Cedar River basin, Wis., where surplus water may be diverted, and methods to determine low-flow characteristics at additional sites are presented. The low-flow characteristics were determined by various methods at 71 sites. For the three gaging stations in the basin, frequency analysis was used to determine the low-flow characteristics. At 17 partial-record sites correlation analyses were used to estimate the low-flow characteristics. Where only a single base-flow measurement was available (41 sites), equations were developed to estimate low-flow characteristics. The relationships were determined from multiple-regression analyses that related low-flow characteristics at gaging stations, low-flow partial-record stations, and sewage-treatment-plant sites to the drainage area and base-flow index values. The standard errors of estimate were determined to be 25 percent for the Q7,2 equation and 34 percent for the Q7,10 equation. For the main stem of the Red Cedar River where only one discharge measurement was available the low-flow characteristics were determined from a drainage area-discharge relationship. Low-flow characteristics were determined at an additional 30 sites in the Red Cedar River basin by various methods. The method used for these sites depended upon the type and amount of data available at each site.

Wisconsin↗
USGS1979

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

Low-flow characteristics of streams in the Lake Superior basin include estimates of low-flow frequency and flow duration at 9 gaging stations, low-flow frequency at 16 low-flow partial-record stations and 38 miscellaneous sites; and a list of base-flow discharge measurement is available. The equations were determined from multiple-regression analyses that relate low-flow 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. Standard error provides the user with the expected degree of accuracy for each method. (Woodard-USGS)

Wisconsin↗
USGS1978

Low-flow characteristics of streams in the lower Wisconsin River basin

Low-flow characteristics of streams in the lower Wisconsin River basin are presented. Included are estimates of low-flow frequency and flow duration at 11 gaging stations; low-flow frequency characteristics at 26 low-flow partial-record stations and 70 miscellaneous sites; and a list of low-flow discharge measurements at 155 miscellaneous sites where insufficient data were available to estimate low-flow characteristics. Relations are provided to estimate low-flow characteristics at ungaged sites and at sites where one base-flow 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. 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. Standard error provides the user with the expected degree of accuracy for each method. Low-flow characteristics estimated for the lower Wisconsin River basin have a high degree of reliability when compared with other basins in Wisconsin, Reliable estimates appear to be related to the relatively uniform geologic features in the basin.

Wisconsin↗
USGS1974

Low-flow characteristics of Wisconsin streams at sewage-treatment plants

Low-flow characteristics of Wisconsin streams at 415 sewage -treatment plants are presented in this report. The low-flow characteristics presented are the annual minimum 7-day mean flow that occurs on the average of once in 2 years (Q7, 2) and the annual minimum 7 -day mean flow that occurs on the average of once in 10 years (Q7, 10). The low-flow characteristics at most sewage-treatment plants were determined by correlating base-flow measurements at the sewage- treatment plants to the concurrent daily mean flow at continuous-record gaging stations in the area. The Q7, 2 and Q7, 10 discharges determined by a frequency analysis at the continuous-record gaging stations were used to estimate the Q7, 2 and Q7,10 at the sewage-treatment plants. For some sewage-treatment plants the low-flow characteristics were also determined by frequency analysis at nearby continuous -record gaging stations or correlation analysis at nearby low-flow, partial-record stations. The accuracy of the estimated low-flow characteristics is evaluated according to the type and amount of data available used to determine the low-flow characteristics. The accuracy determined by the standard error of estimate for the 10-year low flow (SE10) ranged from 18 percent at continuous -record gaging stations to 70 percent when only three base-flow measurements were available. The SE10 of 70 percent is larger than anticipated when the project was initiated. This was the result of extremely poor base-flow conditions during the 2-year data-collection period.

Wisconsin↗