Sea ice scouring on the inner shelf of the southeastern Canadian Beaufort Sea
Arnaud Hequette, Marc Desrosiers, Peter W. Barnes
1995, Marine Geology (128) 201-219
About 2200 ice scours were observed and analyzed over a distance of approximately 500 km on the inner shelf of the southeastern Canadian Beaufort Sea. Ice scours were divided into two types based on their morphology: multiple scours consisting of a series of parallel scours and ridges, and single scours....
Modeling hexavalent chromium reduction in groundwater in field-scale transport and laboratory batch experiments
J.C. Friedly, J.A. Davis, D.B. Kent
1995, Water Resources Research (31) 2783-2794
A plausible and consistent model is developed to obtain a quantitative description of the gradual disappearance of hexavalent chromium (Cr(VI)) from groundwater in a small-scale field tracer test and in batch kinetic experiments using aquifer sediments under similar chemical conditions. The data exhibit three distinct timescales. Fast reduction occurs in...
Use of a reactive gas transport model to determine rates of hydrocarbon biodegradation in unsaturated porous media
Arthur L. Baehr, Ronald J. Baker
1995, Water Resources Research (31) 2877-2882
A mathematical model is presented that simulates the transport and reaction of any number of gaseous phase constituents (e.g. CO2, O2, N2, and hydrocarbons) in unsaturated porous media. The model was developed as part of a method to determine rates of hydrocarbon biodegradation associated with natural cleansing at petroleum product...
An empirical model of the phytoplankton chlorophyll : carbon ratio-the conversion factor between productivity and growth rate
James E. Cloern, Christian Grenz, Lisa Vidergar-Lucas
1995, Limnology and Oceanography (40) 1313-1321
We present an empirical model that describes the ratio of phytoplankton chlorophyll a to carbon, Chl: C, as a function of temperature, daily irradiance, and nutrient-limited growth rate. Our model is based on 219 published measurements of algal cultures exposed to light-limited or nutrient-limited growth conditions. We illustrate an approach...
A strategy for delineating the area of ground-water contribution to wells completed in fractured bedrock aquifers in Pennsylvania
D. W. Risser, G. J. Barton
1995, Water-Resources Investigations Report 95-4033
Delineating a contributing area to a well completed in a fractured bedrock aquifer in Pennsylvania is difficult because the hydrogeologic characteristics of fractured rocks are extremely complex. Because of this complexity, a single method or technique to delineate a contributing area will not be applicable for all wells completed in...
Bridge-scour analysis on Cuchillo Negro Creek at the Interstate 25 crossing near Truth or Consequences, New Mexico
S. D. Waltemeyer
1995, Water-Resources Investigations Report 95-4050
A sediment-transport model to simulate channel change was applied to a 1-mile reach of Cuchillo Negro Creek at the Interstate 25 crossing at Truth or Consequences, New Mexico, using the Bridge-Stream Tube model for Alluvial River Simulation (BRI-STARS). The 500-year flood discharge was estimated to be 10,700 cubic feet per...
Water budget and simulation of one-dimensional unsaturated flow for a flood- and a sprinkler-irrigated field near Milford, Utah
D. D. Susong
1995, Water-Resources Investigations Report 95-4072
Ground-water recharge to basin-fill aquifers from unconsumed irrigation water in the western United States is being reduced as irrigators convert to more efficient irrigation systems. In some areas, these changes in irrigation methods may be contributing to ground-water-level declines and reducing the quantity of water available to downgradient users. The...
Selected chemical characteristics and acute toxicity of urban stormwater, streamflow, and bed material, Maricopa County, Arizona
Thomas J. Lopes, Kenneth D. Fossum
1995, Water-Resources Investigations Report 95-4074
The chemistry and toxicity of urban stormwater, streamflow, and bed material in the Phoenix, Arizona, area were characterized to determine if urban stormwater could degrade the quality of streams. Toxic phases of stormwater (oil and grease, suspended solids, dissolved metals, and dissolved organics) were identified to aid water-quality managers minimize...
Synthesis of natural flows at selected sites in and near the Milk River basin, Montana, 1928-89
L. E. Cary, Charles Parrett
1995, Water-Resources Investigations Report 95-4022
Natural monthly streamflows were synthesized for the years 1928-89 at 2 sites in the St. Mary River Basin and 11 sites in the Milk River Basin in north- central Montana. The sites are represented as nodes in a streamflow accounting model being developed by the Bureau of Reclamation for the...
Applying computer simulation models as learning tools in fishery management
Barry L. Johnson
1995, North American Journal of Fisheries Management (15) 736-747
Computer models can be powerful tools for addressing many problems in fishery management, but uncertainty about how to apply models and how they should perform can lead to a cautious approach to modeling. Within this approach, we expect models to make quantitative predictions but only after all model inputs have...
Benthic macrofauna data for San Francisco Bay, California, September 1986
Laurence E. Schemel, J.K. Thompson, J.G. Harmon, B. T. Yost
1995, Open-File Report 95-291
Benthic macrofauna were collected during September 1986 to evaluate locations for long-term monitoring stations as part of the U.S. Geological Survey Regional Effects Monitoring Program in San Francisco Bay, California. Three to ten replicate samples were collected with a modified Van Veen sampler (0.05 m2 area) at ten locations. One...
Simulation of hydrodynamics and solute transport in the Neuse River estuary
Jeanne C. Robbins, Jerad Bales
1995, Open-File Report 94-511
An investigation was conducted to characterize flow, circulation, and transport in the Neuse River estuary, North Carolina. The study included a detailed field-measurement program and the calibration, validation, and application of a physically realistic numerical model of hydro- dynamics and transport through a 40-kilometer reach of the estuary. Water level,...
Reassessment of hydrogeologic data and refinement of a regional ground-water-flow model for the Milford-Souhegan glacial-drift aquifer, Milford, New Hampshire
Joseph R. Olimpio, Philip T. Harte
1995, Open-File Report 95-281
Simulation of hydrodynamics and solute transport in the Pamlico River estuary, North Carolina
Jerad Bales, Jeanne C. Robbins
1995, Open-File Report 94-454
An investigation was conducted to characterize flow, circulation, and solute transport in the Pamlico River estuary, North Carolina. The study included a detailed field-measurement program and the calibration, validation, and application of a physically realistic numerical model of hydro- dynamics and transport. Water level, salinity, water temperature, wind speed and...
Analytical results for soil samples and plots of results of R-mode factor analysis of soil and soil-gas data; Dixie Valley Known Geothermal Resource Area, northern Dixie Valley, Nevada
Margaret Hinkle, Paul H. Briggs, J. M. Motooka, R. J. Knight
1995, Open-File Report 95-485
Theoretical models of heterogeneous media for electrical prospecting methods with direct currents
Sabba S. Stefanescu (translator), Adel A. R. Zohdy
1995, Open-File Report 95-544
Progress made in groundwater flow and transport modeling
Mary C. Hill, Chunmiao Zheng
1995, Eos, Transactions, American Geophysical Union (76)
A special session, “Automated Parameter Identification and Sensitivity Analysis in Groundwater Flow and Transport,” was held at the Spring AGU meeting last May to explore recent scientific and technological developments in this expanding research area. The problems and approaches discussed are crucial to any field of Earth science in which...
Spring-summer survival rates of yearling versus adult mallard females
Ronald E. Reynolds, Robert J. Blohm, James D. Nichols, James E. Hines
1995, Journal of Wildlife Management (59) 691-696
Knowledge of the timing, magnitude, and cause of mortality in wildlife populations is imperative for developing management strategies that protect or improve the status of these populations. Age- and sex-specific population parameter estimates provide the most useful information for this purpose. Numerous studies have provided information about survival rates in...
Robustness of survival estimates from radio-telemetry studies with uncertain relocation of individuals
Christine M. Bunck, Chiu-Lan Chen, Kenneth H. Pollock
1995, Journal of Wildlife Management (59) 790-794
Traditional methods of estimating survival from radio-telemetry studies use either the Trent-Rongstad approach (Trent and Rongstad 1974, Heisey and Fuller 1985) or the Kaplan-Meier approach (Kaplan and Meier 1958; Pollock et al. 1989a,b). Both methods appear to require the assumption that relocation probability for animals with a functioning radio is...
Age-class separation of blue-winged ducks
William L. Hohman, Joseph L. Moore, Daniel J. Twedt, John G. Mensik, E. Logerwell
1995, Journal of Wildlife Management (59) 727-735
Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of...
Spring-staging ecology of midcontinent greater white-fronted geese
Gary Krapu, Kenneth J. Reinecke, Dennis G. Jorde, S. Gay Simpson
1995, Journal of Wildlife Management (59) 736-746
A major part of the midcontinent greater white-fronted goose (Anser albifrons) population stages for several weeks in spring in the Rainwater Basin Area (RBA) of south-central Nebraska where substantial mortality from disease occurs periodically. Effective management of this population requires better data on use of habitat, vulnerability to disease, and...
Geographic variation in band reporting rates for mallards based on reward banding
James D. Nichols, Ronald E. Reynolds, Robert J. Blohm, Robert E. Trost, James E. Hines, Judith P. Bladen
1995, Journal of Wildlife Management (59) 697-708
We conducted a reward band study on mallards (Anas platyrhynchos) to estimate and test hypotheses about sources of variation in band reporting rate. We banded 25,398 mallards with standard and 100 reward bands (3 mallards banded with standard bands for every reward-banded mallard) during preseason (Jul-Sep), 1988. We used a...
Volcanic and structural evolution of Taupo Volcanic Zone, New Zealand: A review
C. J. N. Wilson, B. F. Houghton, M.O. McWilliams, Marvin A. Lanphere, S.D. Weaver, R. M. Briggs
1995, Journal of Volcanology and Geothermal Research (68) 1-28
The Taupo Volcanic Zone (TVZ) in the central North Island is the main focus of young volcanism in New Zealand. Andesitic activity started at c. 2 Ma, joined by voluminous rhyolitic (plus minor basaltic and dacitic) activity from c. 1.6 Ma. The TVZ is c. 300 km long (200 km...
A mass proportion method for calculating melting reactions and application to melting of model upper mantle lherzolite
Michael J. Walter, Thomas W. Sisson, Dean C. Presnall
1995, Earth and Planetary Science Letters (135) 77-90
We present a method for calculating quantitative melting reactions in systems with multiple solid solutions that accounts for changes in the mass proportions of phases between two points at different temperatures along a melting curve. This method can be applied to any data set that defines the phase proportions along...
Geohydrology and ground-water quality of east King County, Washington
G. L. Turney, S. C. Kahle, N. P. Dion
1995, Water-Resources Investigations Report 94-4082
East King County is a 250-square-mile area east of Seattle underlain by as much as 1,200 feet of unconsolidated deposits of glacial and nonglacial origin. A surficial geology map and 12 geohydrologic sections were constructed and used to delineate 10 geohydrologic units, 4 of which are major aquifers. Annual precipitation...
