Skip to main content

J.F. Walker

thumbnail
Transient recharge to the water table is often not well understood or quantified. Two approaches for simulating transient recharge in a ground water flow model were investigated using the Trout Lake watershed in north-central Wisconsin: (1) a traditional approach of adding recharge directly to the water table and (2) routing the same volume of water through an unsaturated zone column to the water table. Areas with thin (less than 1 m) unsaturated zones showed little difference in timing of recharge between the two approaches; when water was routed through the unsaturated zone, however, less recharge was delivered to the water table and more discharge occurred to the surface because recharge direction and magnitude...
Categories: Publication; Types: Citation; Tags: Ground Water
thumbnail
A substantial proportion of natural streams in the United States and Canada are affected by ice cover during the winter. To substantiate the currently used procedures for measuring streamflow during the winter, the U.S. Geological Survey (USGS) and Water Survey of Canada (WSC) began independent, coordinated programs for research and development related to the measurement of streamflow under an ice cover. Detailed measurements of vertical velocity profiles under ice covers in field settings were collected by each agency in accordance with standardized guidelines. The data were then compiled into a joint database. This paper presents a description of the two measurement programs, describes the structure and format...
thumbnail
Seventeen methods for estimating ice-affected streamflow are evaluated for potential use with the U.S. Geological Survey streamflow-gaging station network. The methods evaluated were identified by written responses from U.S. Geological Survey field offices and by a comprehensive literature search. The methods selected and techniques used for applying the methods are described in this report. The methods are evaluated by comparing estimated results with data collected at three streamflow-gaging stations in Iowa during the winter of 1987-88. Discharge measurements were obtained at 1- to 5-day intervals during the ice-affected periods at the three stations to define an accurate baseline record. Discharge records were...
Categories: Publication; Types: Citation; Tags: Water Supply Paper
thumbnail
Measurements of groundwater-surface water exchange at three wetland stream sites were related to patterns in benthic productivity as part of the US Geological Survey's Northern Temperate Lakes-Water, Energy and Biogeochemical Budgets (NTL-WEBB) project. The three sites included one high groundwater discharge (HGD) site, one weak groundwater discharge (WGD) site, and one groundwater recharge (GR) site. Large upward vertical gradients at the HGD site were associated with smallest variation in head below the stream and fewest gradient reversals between the stream and the groundwater beneath the stream, and the stream and the adjacent streambank. The WGD site had the highest number of gradient reversals reflecting the...
Categories: Publication; Types: Citation
thumbnail
Pumping from closely spaced wells in the Central Brown County area and the Fox Cities area near the north shore of Lake Winnebago has resulted in the formation of deep cones of depression in the vicinity of the two pumping centers. Water-level measurements indicate there has been a steady decline in water levels in the vicinity of these two pumping centers for the past 50 years. This report describes the use of ground-water optimization modeling to efficiently allocate the ground-water resources in the Lower Fox River Valley. A 3-dimensional ground-water flow model was used along with optimization techniques to determine the optimal withdrawal rates for a variety of management alternatives. The simulations were...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.