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Water yield was estimated for each of the five regions that represent contrasting hydrologic regimes in the 10,400 square miles of the Rio Grande basin above Embudo, New Mexico. Water yield was estimated as 2,800 cubic feet per second for the San Juan Mountains, and 28 cubic feet per second...

The upper Black Squirrel Creek basin in eastern El Paso County, Colorado, is underlain by an alluvial aquifer and four bedrock aquifers. The climate of the area is semiarid, and streamflow is irregular. The alluvial aquifer has supplied water to wells since the late 1800's when ranchers first pumped water...

The N Aquifer is the main source of water in the 5,400 sq mi Black Mesa area in the Navajo and Hopi Indian Reservations in northeastern Arizona. Water in the aquifer is under confined conditions in the central 3,300 sq mi of the area. Maximum saturated thickness is about 1,050...

Four types of volcanogenic manganese deposits, distinguished on the basis of geologic, geochemical, and geophysical characteristics, appear to result from a combination of volcanic and hydrothermal processes related to hot-spring activity in oceanic environments. We compare these four desposit types, here called the Franciscan, Cuban, Olympic Peninsula, and Cyprus,...

On a regional scale, the groundwater system of the northern Mississippi embayment is composed of a series of nonindurated clastic sediments that overlie a thick sequence of Paleozoic carbonate, sandstones, and shales. The units that comprise the geohydrologic framework of this study are the alluvium-lower Wilcox Aquifer the Midway confining...

A one dimensional, unsteady-state temperature model using the equilibrium temperature approach (with air temperature used to estimate equilibrium temperature) is used to evaluate the effects of two Army Corps of Engineers dams and resulting reservoirs on the McKenzie River, from Delta Park (River Kilometer 99.9) to Leaburg Dam (River Kilometer...

The Big Sioux aquifer in Moody County is a 55 sq mi, water table aquifer hydraulically connected to the Big Sioux River. The average thickness is 22 ft and the maximum thickness is 54 ft. A digital model was developed to simulate groundwater flow in the Big Sioux aquifer in...

Two adjacent burial areas were excavated in a clay-rich till at a radioactive waste disposal site near West Valley in Cattaraugus County, N.Y.: (1) which contains mainly low-level radioactive wastes generated onsite by a nuclear fuel reprocessing plant, has been in operation since 1966; and (2) which contains commercial low-level...

A statistical method was developed to estimate monthly natural dissolved-solids discharge at selected sites in the Upper Colorado River Basin. Natural dissolved-solids discharge was defined as the rate of inorganic-solute flow past a specific site that would have occurred if there had been no water-resources development in the basin upstream...

Rainfall-runoff models were developed for a multiple-dwelling residential catchment (2 applications), a single-dwelling residential catchment, and a commercial catchment in Fresno, California, using the U.S. Geological Survey Distributed Routing Rainfall-Runoff Model (DR3M-II). A runoff-quality model also was developed at the commercial catchment using the Survey 's Multiple-Event Urban Runoff Quality...

The U.S. Geological Survey, in cooperation with the Arkansas Soil and Water Conservation Commission, conducted a hydrologic investigation of the lower Little Red River from near Searcy, Arkansas (mi 31.7), to the river 's mouth at its confluence with the White River. During 1983 and 1984, data were collected on...

Ninety-nine percent of the 79.72 million gal/d of water used in Pasco County, Florida is groundwater from the Upper Floridan aquifer. In addition, 53.5 million gal/d is exported for use in Pinellas County. Chemical quality of the water generally falls within recommended limits for drinking water except near the coast....

A model was developed to be useful for predicting changes in streamflow as a result of groundwater pumping. The stream aquifer model is especially useful for simulating streams that flow intermittently owing to leakage to the aquifer or diversion for irrigation or streams that become perched owing to declining hydraulic...

At the request of the U.S. Bureau of Land Management, approximately 85,100 acres of the Whipple Mountains Wilderness Study Area (CDCA-312) and 1,380 acres of the Whipple Mountains Addition Wilderness Study Area (AZ-050-010) were evaluated for identified mineral resources (known) and mineral resource potential (undiscovered). In this report, the Whipple...

Proposed construction of two dams on Cottonwood Creek California , has caused concern that resulting streamflow modification may alter downstream channel morphology. Baseline information on Cottonwood Creek channel characteristics from 1982-83 field surveys and 1940-84 aerial photographs indicates an alluvial channel that consists of a braided inner main channel within...

This report presents a finite-difference model and its associated modular computer program. The model simulates flow in three dimensions. The report includes detailed explanations of physical and mathematical concepts on which the model is based and an explanation of how those concepts are incorporated in the modular structure of the...

A habitat suitability index (HSI) model, developed for the American oyster,Crassostrea virginica, along the Gulf of Mexico, was field tested on 38 0.1-ha reef and nonreef sites in Galveston Bay, Texas. The HSI depends upon six (HSI1) or, optionally, eight (HSI2) variables. The six variables are percent of...

Seabirds in the saline marsh of coastal Louisiana nest on the islands that are more isolated, smaller, have lower percentages of woody vegetation, and higher percentages of herbaceous vegetation and beach habitat. Only moderate variation in these habitat features was demonstrated among years of colonization. The factors...

Longear sunfish were collected from a stream contaminated with mine tailings rich in lead (Pb), cadmium (Cd) and zinc (Zn). Blood samples were analysed for δ-aminolevulinic acid dehydratase (ALA-D) activity and Pb concentration. Vertebrae were tested for bone strength and composition, and Pb, Zn, and Cd concentrations were determined in...

Analytical solutions have been developed for many conceptual models of solute transport in groundwater (Bear 1979). Although these models usually rely on assumptions too restrictive for accurate description of actual field situations, they are useful in understanding groundwater transport and in evaluating the relative importance of the subsurface processes affecting...

"Wildlife 2000" is the proceedings of a conference held 7-11 October 1984, near Lake Tahoe, California, the objective of which was to present an up-to-date synthesis of models that predict the responses of wildlife to habitat change. This extremely attractive, well-produced volume has been well received by the wildlife...

The 6845 ± 50 BP climactic eruption of Mount Mazama discharged 47 ± 9 km3 of vertically zoned calc-alkaline magma, affording a virtually complete section through the chamber. Evidence for two andesitic parents with different trace-element (particularly Sr) and water contents is preserved in the ejecta. Prior to eruption, a...