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The groundwater system in southern Oahu, Hawaii consists of a thick, areally extensive freshwater lens overlying a zone of transition to a thick saltwater body. This system is analyzed in cross section with a variable-density groundwater flow and solute transport model on a regional scale. The simulation is difficult, because...

The Morgan Hill earthquake, a moderate-size (M_g=6.1, ML =6.2, M=6.2) event, was felt throughout central California on April 24, 1984. The epicenter of the earthquake was located near Halls Valley southwest of Mount Hamilton, and the event is presumed to have occurred on the Calaveras fault. Damage, however, was concentrated near the south end of the Anderson Reservoir and in the town of Morgan Hill. A preliminary assessment by the California Office of Emergency Services estimated damage to private property at $7.0 million and to local-government facilities at $0.5 million, for a total of $7.5 million in damage. Acknowledgments.--! appreciate the helpful suggestions of Joseph I. Ziony and Robert D. Brown, Jr. These studies were aided by the generous cooperation of the many landowners who permitted access to their properties....

An attempt was made by the U.S. Geological Survey to develop parameter-estimation techniques for two rainfall-loss computation methods used in the U.S. Army Corps of Engineers ' flood-hydrograph model (HEC-1). Six rainfall-loss parameters were investigated - four for the Exponential Loss-Rate method and two for the Initial and Uniform Loss-Rate...

The Heat- and Soil-Transport Program (HST3D) simulates groundwater flow and associated heat and solute transport in three dimensions. The three governing equations are coupled through the interstitial pore velocity, the dependence of the fluid density on pressure, temperature, the solute-mass fraction , and the dependence of the fluid viscosity on...

The Withlacoochee River Basin of the Southwest Florida Water Management District is a management area of about 2030 sq mi in west-central Florida containing large reserves of potable water in the Upper Floridan aquifer. Results of reconnaissance test drilling indicate that the Upper Floridan aquifer may be treated as an...

A three-dimensional digital model that simulates transient flow in the alluvial aquifer system underlying the Albuquerque-Belen Basin, New Mexico, was constructed as part of a regional aquifer study of the southwest alluvial basins. The model simulates hydraulic heads and changes in hydraulic heads for 1907 to 1979. Hydraulic-conductivity values used...

The Inyan Kara, Minnelusa, and Madison aquifers are the principal sources of ground water in the northern Black Hills, South Dakota and Wyoming, and Bear Lodge Mountains, Wyoming. The aquifers are exposed in the Bear Lodge Mountains and the Black Hills and are about 3,000 to 5,000 ft below the...

A recent evaluation of groundwater and material in the blockage impounding Castle Lake shows that the blockage is potentially unstable against failure from piping due to heave and internal erosion when groundwater levels are seasonally high. There is also a remote possibility that a 6.8 or greater magnitude earthquake could...

Precipitation data were collected from October 1980 through September 1983 from three recording gages at the Western New York Nuclear Service Center, and surface water data were collected at three continuous-record gaging stations and one partial-record gage on streams that drain a 0.7 sq km part of the site. Seepage...

Strip mining for coal in southwestern Washington may be affecting the water quality of streams. To investigate these possible effects, five streams were selected for study of water quality in each of the two coal bearing areas: the Centralia-Chehalis coal district, and Kelso-Castle Rock coal area. In the Centralia-Chehalis coal...

The Onondaga aquifer is a nearly flat-lying, 25- to 110-foot-thick, cherty limestone with moderately developed karst features such as sinkholes, disappearing streams, and solution-widened joints. Most groundwater moves through solution-widened bedding planes, although some moves through vertical joints. The yield of water from 42 wells ranges from 3 to 100...

The magnitude, frequency and extent of the flood of October 7, 1985 at the Rio Coamo in the vicinity of the Coamo Dam and Highway 52 bridge in southern Puerto Rico, were investigated. The observed flood profiles were used to calibrate a step-backwater model. The calibrated model was then used...

At an extensometer site near Eloy, Arizona, 1.09 m of land subsidence caused by groundwater withdrawal were measured by leveling in 1965-83. The extensometer, which partially penetrates the compressible sediments, recorded 0.82 m of compaction during the same period. By use of a one-dimensional model, cumulative daily compaction values were...

This report documents FORTRAN computer code for solving problems involving variably saturated single-phase flow in porous media. The flow equation is written with total hydraulic potential as the dependent variable, which allows straightforward treatment of both saturated and unsaturated conditions. The spatial derivatives in the flow equation are approximated by...

Major flooding in the lower Pearl River basin in recent years has caused extensive damage to homes and highways in the area. In 1980 and 1983, Interstate Highway 10 and U.S. Highway 190 were overtopped. In 1983, the Interstate Highway 10 crossing was seriously damaged by the flood. The U.S....

A quasi-three-dimensional digital groundwater flow model of a shallow outwash aquifer system at Olean, New York, was developed to study the effects of several pumping alternatives on groundwater flow and stream seepage. Nitrogen compounds have contaminated the aquifer in an industrial park in North Olean. Pumping from seven industrial production...

A model is described for simulating three-dimensional groundwater flow and solute transport in oil shale and associated geohydrologic units. The model treats oil shale as a dual-porosity medium by simulating flow and transport within fractures using the finite-element method. Diffusion of solute between fractures and the essentially static water of...

This report describes the application and results of an unsteady-flow model for the Milwaukee Harbor Estuary. The model simulates unsteady and upstream flow occurring in the estuary as a result of Lake Michigan Seiche. The discharge computed by the model indicates that upstream flow occurs throughout the estuary during periods...

Analyses indicate that water quality in the San Juan River drainage basin upstream from Shiprock, New Mexico, is quite variable from station to station. Analyses are based on water quality data from the U.S. Geological Survey WATSTORE files and the New Mexico Environmental Improvement Division 's files. In the northeastern...

A FORTRAN-77 computer program code that helps solve a variety of aquifer management problems involving the control of groundwater hydraulics. It is intended for use with any standard mathematical programming package that uses Mathematical Programming System input format. The computer program creates the input files to be used by the...

Water in Cedar Creek Reservoir in northeast Texas had volume-weighted average concentrations of less than 140 milligrams per liter of dissolved solids, less than 30 milligrams per liter of dissolved sulfate, and less than 25 milligrams per liter of chloride between vh nuary 1977 and August 1984. The water was...

Pursuant to the Ak-Chin Indian Community Water Rights Settlement Act (Public Law 95-328-enacted on July 28, 1978) a study was undertaken to assess the effect of proposed groundwater withdrawal from Federal lands near the reservation. The first area to be evaluated was the northern part of the Vekol Valley. The...

The water levels of the navigation pools on the Mississippi River are maintained by the operation of tainter and roller gates at the locks and dams. Discharge ratings for the gates on Lock and Dam 21, at Quincy, Illinois, were developed from current meter discharge measurements made in the forebays...

The water levels of the navigation pools on the Mississippi River are maintained by the operation of tainter and roller gates at the locks and dams. Discharge ratings for the gates on Lock and Dam 20, at Canton, Missouri, were developed from current meter discharge measurements made in the forebays...