Modelling streamwater chemistry as a mixture of soilwater end-members - An application to the Panola Mountain catchment, Georgia, U.S.A.
R. P. Hooper, N. Christophersen, N.E. Peters
1990, Journal of Hydrology (116) 321-343
Streamwater chemistry at Panola Mountain research catchment, Georgia, U.S.A., is explained as a mixture of representative soilwater solutions that are considered to be temporally invariant to a first approximation. The selection of three end-members from all sampled soil waters is evaluated by comparing the observed and predicted streamwater concentration of...
Modelling streamwater chemistry as a mixture of soilwater end-members - A step towards second-generation acidification models
N. Christophersen, C. Neal, R. P. Hooper, R.D. Vogt, S. Andersen
1990, Journal of Hydrology (116) 307-320
In present acidification models, soilwater characteristics, though modelled, are seldom checked against field observations. Given that such data are now collected as part of many catchment studies, a technique is developed whereby stream water can be predicted as a mixture of the observed soilwater classes or end-members. Provided that a...
Digital recordings of aftershocks of the 17 October 1989 Loma Prieta, California, earthquake
Charles C. Mueller, Gary Glassmoyer
1990, Open-File Report 90-503
After the 17 October 1989 Loma Prieta, central California, earthquake (291 00:04:15.25 UTC, Ms=7.1), the U. S. Geological Survey recorded aftershocks at sites of seismologic and engineering interest. This report describes a seismic-waveform dataset collected from 17 October 1989 (291 UTC) to 14 March 1990 (073 UTC) with GEOS digital...
Simulation of ground-water flow in the Mississippi River Valley alluvial aquifer in eastern Arkansas
G.L. Mahon, A. H. Ludwig
1990, Water-Resources Investigations Report 89-4145
The U.S Geological Survey has developed and calibrated a digital model of the flow system in the alluvial aquifer as part of a multiagency Eastern Arkansas Region Comprehensive Study being conducted by the U. S. Army Corps of Engineers. Other cooperating agencies include the U.S. Soil Conservation Service, the Arkansas...
Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division
G.J. Stiltner
1990, Open-File Report 89-576
In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration...
A graphical kernel system (GKS) version of computer program MODPATH-PLOT for displaying path lines generated from the U.S. Geological Survey modular three-dimensional ground-water flow model
D.W. Pollock
1990, Open-File Report 89-622
Regional evaluation of hydrologic factors and effects of pumping, St Peter-Jordan aquifer, Iowa
M. R. Burkart, Robert Buchmiller
1990, Water-Resources Investigations Report 90-4009
The St. Peter-Jordan aquifer includes the Cambrian Jordan Sandstone and the overlying Ordovician Prairie du Chien Group and St. Peter Sandstone. The aquifer is present throughout Iowa and is confined beneath other aquifers in much of the State. Information on the aquifer available from drillers and contractors, provided estimates of...
Geohydrology and numerical model analysis of ground-water flow in the Pullman-Moscow area, Washington and Idaho
W. E. Lum II, James L. Smoot, Dale R. Ralston
1990, Water-Resources Investigations Report 89-4103
The geohydrology of the Pullman, Washington-Moscow, Idaho area was investigated by mapping geohydrologic units, determining the distribution of hydraulic head in each unit, and determining some of the components of the water budget. This information was used to construct a three- dimensional groundwater-flow model that incorporates three layers--a surficial loess...
How to construct seven paper models that describe faulting of the earth
Tau Rho Alpha, John C. Lahr
1990, Open-File Report 90-257-B
Application of digital elevation models to delineate drainage areas and compute hydrologic characteristics for sites in the James River basin, North Dakota
G.J. Wiche, S.K. Jenson, J. V. Baglio Jr., Julia O. Domingue
1990, Open-File Report 90-593
No abstract available....
Tectonic history of the northern Nabitah fault zone, Arabian Shield, Kingdom of Saudi Arabia
J. E. Quick, Paul S. Bosch
1990, Open-File Report 90-316
Geologic mapping combined with structural, petrographic, and geochemical investigations were used to evaluate the motion and paleogeographic setting of the northern Nabitah fault zone. The orientation and asymmetry of small structures in three areas along the fault zone suggest that motion was primarily left-lateral strike slip. East of the fault...
Geology and ground-water resources of the Memphis Sand in western Tennessee
William Scott Parks, J. K. Carmichael
1990, Water-Resources Investigations Report 88-4182
The Memphis Sand of the Claiborne Group of Tertiary age underlies approximately 7,400 square miles in western Tennessee. The formation primarily consists of a thick body of veryfine to very coarse sand that includes subordinate lenses or beds of clay and silt at various horizons. The Memphis Sand ranges from...
Geology and ground-water resources of the Cockfield Formation in western Tennessee
W. S. Parks, J. K. Carmichael
1990, Water-Resources Investigations Report 88-4181
The Cockfield Formation of the Claiborne Group of Tertiary age underlies approximately 4,000 sq mi in western Tennessee. The formation consists primarily of lenticular beds of very fine to coarse sand, silt, clay, and lignite. The Cockfield Formation has been extensively eroded, and the original thickness is preserved only in...
Effects of present and projected ground-water withdrawals on the Twin Cities aquifer system, Minnesota
Michael Schoenberg
1990, Water-Resources Investigations Report 90-4001
The Twin Cities aquifer system in Minnesota contains 5 aquifers and 4 confining units composed of 14 stratigraphic units. Bedrock aquifers consist of friable sandstones and highly fractured carbonate rocks; aquifers in the glacial drift consist of outwash and alluvium. From 1880 to 1980, groundwater withdrawals had caused long-term declines...
Applications of the USGS aftershock sequence model and guidelines for drafting aftershock forecasts
P.A. Reasenberg
1990, Open-File Report 90-341
Geohydrology and simulation of ground-water flow in the carbonate rocks of the Valley Creek basin, eastern Chester County, Pennsylvania
R. A. Sloto
1990, Water-Resources Investigations Report 89-4169
Sixty-eight percent of the 22.6-square-mile Valley Creek basin is underlain by Cambrian and Ordovician limestone and dolomite. Ground water flows through a network of interconnected secondary openings; primary porosity is virtually nonexistent. Some of these openings have been enlarged by solution. Secondary porosity and permeability exhibit great spatial variability, and...
Ground-water flow in the Gulf Coast aquifer systems, south central United States — A preliminary analysis
A. K. Williamson, H. F. Grubb, J. S. Weiss
1990, Water-Resources Investigations Report 89-4071
A major objective of the Gulf Coast Regional Aquifer-System Analysis is to use digital models of regional groundwater flow systems to develop better understanding and to improve management of the resource. Modeling is used to synthesize information about the aquifer systems and to test hypotheses about the relative importance of...
PRECONDITIONED CONJUGATE-GRADIENT 2 (PCG2), a computer program for solving ground-water flow equations
Mary C. Hill
1990, Water-Resources Investigations Report 90-4048
This report documents PCG2 : a numerical code to be used with the U.S. Geological Survey modular three-dimensional, finite-difference, ground-water flow model . PCG2 uses the preconditioned conjugate-gradient method to solve the equations produced by the model for hydraulic head. Linear or nonlinear flow conditions may be simulated. PCG2 includes...
The San Andreas Fault System, California
Robert E. Wallace, editor(s)
1990, Professional Paper 1515
Maps of northern and southern California printed on flyleaf inside front cover and on adjacent pages show faults that have had displacement within the past 2 million years. Those that have had displacement within historical time are shown in red. Bands of red tint emphasize zones of historical displacement; bands...
Effects of urbanization on peak streamflows in four Connecticut communities, 1980-84
L.A. Weiss
1990, Water-Resources Investigations Report 89-4167
Ratios of peak flows in urban basins to peak flows in rural basins in Connecticut are about 1.5 to 6.1 for the 2-year flood and 1.1 to 4.3 for the 100-year flood. The lower ratios, in each case, apply where 30% of the area is served by storm sewers, and...
Analysis of alternative modifications for reducing backwater flooding at the Honey Creek coal strip mine reclamation site in Henry County, Missouri
T.W. Alexander
1990, Water-Resources Investigations Report 90-4068
Regression modeling of ground-water flow
Richard L. Cooley, Richard L. Naff
1990, Techniques of Water-Resources Investigations 03-B4
Joint spacings, mineral modes and grain size measurements for selected granitic rocks in the northern Rockies and in southwest England
Judy Ehlen, E-an Zen
1990, Open-File Report 90-48
A digital simulation of the glacial-aquifer system in the northern three-fourths of Brown County, South Dakota
P.J. Emmons
1990, Water-Resources Investigations Report 88-4198
A digital model was developed to simulate groundwater flow in a complex glacial-aquifer system that includes the Elm, Middle James, and Deep James aquifers in South Dakota. The average thickness of the aquifers ranges from 16 to 32 ft and the average hydraulic conductivity ranges from 240 to 300 ft/day....
Governing equations and model approximation errors associated with the effects of fluid-storage transients on solute transport in aquifers
D.J. Goode
1990, Water-Resources Investigations Report 90-4156
