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Comparisons were made between model-calculated water levels from a one-dimensional analytical model referred to as RAM (Robust Analytical Model) and those from numerical ground-water flow models using a sharp-interface model code. RAM incorporates the horizontal-flow assumption and the Ghyben-Herzberg relation to represent flow in a one-dimensional unconfined aquifer that contains...

Suspended sediment has long been recognized as an important contaminant affecting water resources. Besides its direct role in determining water clarity, bridge scour and reservoir storage, sediment serves as a vehicle for the transport of many binding contaminants, including nutrients, trace metals, semi-volatile organic compounds, a nd numerous pesticides (U.S....

Chemical loads from ground water to the Grand Calumet River and the Indiana Harbor Canal in northwestern Indiana were estimated to aid in determining the total maximum daily load. Data from two previous studies, completed in 1987 and 1993, were used to compute loads. The first study included a ground-water-flow...

The Red River of the North is a complex river system in the north-central plains of the United States. The river continues to impact the people and property within its basin. During the spring of 2001, major flooding occurred for the second time in four years on the Red River...

Water-quality and flow data from 31 sites in nontidal portions of the Chesapeake Bay Basin were analyzed to document annual nutrient and sediment loads and trends for the period 1985 through 1999 as part of an annual reevaluation and reporting for the Chesapeake Bay Program. Annual loads were estimated by...

This paper presents 25 new 40Ar/39Ar dates from the main calc-alkaline ash-flow sheets and related younger plutons of the western San Juan volcanic field, the ash-flow sheets of the Lake City caldera cycle, and veins and other altered rocks in the Lake City region. The goal of the study was...

The stage of Lake Brooklyn, in southwestern Clay County, Florida, has varied over a range of 27 feet since measurements by the U.S. Geological Survey began in July 1957. The large stage changes have been attributed to the relation between highly transient surface-water inflow to the lake and subsurface conduits...

Irondequoit Creek drains 169 square miles in the eastern part of Monroe County. Nutrients transported by Irondequoit Creek to Irondequoit Bay on Lake Ontario have contributed to the eutrophication of the Bay. Sewage-treatment-plant effluent, a major source of nutrients to the creek and its tributaries, was eliminated from the basin...

Previous studies have shown direct evidence of under-seepage at Red Rock Dam on the Des Moines River near Pella, Iowa. Underseepage is thought to occur primarily on the northeast side of the dam in the lower bedrock of the St. Louis Limestone, which consists of discontinuous basal evaporite beds and...

Annual loads and flow-adjusted concentration trends were estimated by use of water-quality and streamflow data collected from 1990 through 1999 at monitoring stations on two tributaries to Chesapeake Bay in Virginia—James River at Cartersville, Va., and Rappahannock River near Fredericksburg, Va. The effects of storm-sampling frequency on the accuracy and...

An investigation of the geology, hydrology, and water quality in the vicinity of a Brownfield redevelopment site in East Moline, Illinois, was designed to determine if metals and organic compounds detected in the fill deposits in this area posed a threat to the water resources. The hydrologic features of concern...

The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to...

Arnold Air Force Base (AAFB) occupies about 40,000 acres in Coffee and Franklin Counties, Tennessee. Numerous site-specific ground-water contamination investigations have been conducted at designated solid waste management units (SWMU?s) at AAFB. Several synthetic volatile organic compounds (VOC?s), primarily chlorinated solvents, have been identified in groundwater samples collected from monitoring...

This report summarizes hydraulic and mechanical properties affecting ground-water flow and aquifer-system compaction in the San Joaquin Valley, a broad alluviated intermontane structural trough that constitutes the southern two-thirds of the Central Valley of California. These values will be used to constrain a coupled ground-water flow and aquifer-system compaction model...

During the rainstorm of June 27, 1995, roughly 330-750 mm of rain fell within a sixteen-hour period, initiating floods and over 600 debris flows in a small area (130 km2) of Madison County, Virginia. Field studies showed that the majority (70%) of these debris flows initiated with a thickness...

The U.S. Geological Survey is one of many agencies providing scientific support to the effort to restore the South Florida Everglades. In September and November 1997 and July 1998, vegetation was sampled at selected sites in the Everglades as part of a study to quantify vegetative resistance to flow. The...

The calibration of a model of flow, temperature, and water quality in the Tualatin River, Oregon, originally calibrated for the summers of 1991 through 1993, was extended to the summers of 1991 through 1997. The model is now calibrated for a total period of 42 months during the May through...

As of September 30, 1999, the surface-water data-collection network of Texas (table 1) included 321 continuous-record streamflow stations (D), 20 continuous-record gage-height only stations (G), 24 crest-stage partial-record stations (C), 40 floodhydrograph partial-record stations (H), 25 low-flow partial-record stations (L), 1 continuous-record temperature station (M1), 25 continuous-record temperature and specific...

The U. S. Geological Survey (USGS) has a prominent role in the Federal Government's comprehensive restoration plan for the south Florida ecosystem encompassing the Everglades-the largest remaining subtropical wilderness in the continental United States. USGS scientists, in collaboration with researchers from the National Park Service (NPS), other governmental agencies, and...

Borehole and surface geophysics were used to investigate ground-water quality affected by a road-deicing salt-storage facility located near a public water-supply well field. From 1994 through 1998, borehole geophysical logs were made in an existing network of monitoring wells completed near the bottom of a thick sand aquifer. Logs of...

This volume is a compilation of significant floods that occurred throughout the United States, Puerto Rico, and the Virgin Islands during 1970 through 1989. A summary of most devastating floods according to amount of damage and lives lost is provided for each year. State-by-state compilations include a description of the...

The collection of nine papers that follow continue the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. The series presents new and sometimes preliminary findings that are of interest to earth scientists in academia, government, and industry; to land and...

Numerical-simulation and optimization techniques were used to evaluate alternatives for the conjunctive management of ground- and surface-water resources of the Hunt­-Annaquatucket­-Pettaquamscutt stream-aquifer system in central Rhode Island. Ground-water withdrawals from the Hunt-Annaquatucket-Pettaquamscutt aquifer exceeded 8 million gallons per day during months of peak water use during 1993­98, and additional withdrawals...

New 1:24,000-scale geologic mapping in the Colorado National Monument Quadrangle and adjacent areas, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of and data for the stratigraphy, structure, geologic hazards in the area from the Colorado River in Grand Valley onto the...

Introduction The Lavinia Planitia quadrangle (V-55) is in the southern hemisphere of Venus and extends from 25 to 50 south latitude and from 330 to 360 longitude. It covers the central and northern part of Lavinia Planitia and parts of its margins. Lavinia Planitia consists of a centralized, deformed lowland flooded...