Conference Papers
Science Quality and Integrity
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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The practical use of simplicity in developing ground water models
The advantages of starting with simple models and building complexity slowly can be significant in the development of ground water models. In many circumstances, simpler models are characterized by fewer defined parameters and shorter execution times. In this work, the number of parameters is used as the primary measure of simplicity and complexity; the advantages of shorter execution times also a
Authors
M. C. Hill
The quest for a safe and effective canine distemper virus vaccine for black-footed ferrets
Canine distemper virus (CDV) causes a systemic disease that is highly virulent to mustelids and other carnivore (Order Carnivora) species and is found worldwide. Endemic canine distemper in wild and domestic carnivores in the United States has made reintroduction of endangered black-footed ferrets (Mustela nigripes) difficult in the absence of safe and effective CDV vaccines and vaccination practi
Authors
Jeffrey Wimsatt, Dean E. Biggins, Elizabeth S. Williams, Victor M. Becerra
The role of biological uptake in iron and manganese cycling in Lake Baikal
The role of biological uptake in the internal cycling of Fe and Mn in Lake Baikal was quantified. Biological uptake, sedimentation consisting of the biogenic and lithogenic fluxes, and remineralization have been evaluated. The results of calculations show that about 5-10% of Fe and Mn accumulated in the lake are annually taken up by biota. More than 80% of this amount is again recycled after remin
Authors
L.Z. Granina, E. Callender
The study of ozone variations in the Las Vegas metropolitan area using remote sensing information and ground observations
Urban development in the Las Vegas Valley, Nevada, has grown rapidly in the past fifty years. Associated with this growth has been a change in landscape from natural cover types to developed urban land mixed with planned vegetation canopy throughout in the metropolitan area. Air quality in the Las Vegas Valley has been affected by increases in anthropogenic emissions and concentrations of carbon m
Authors
G. Xian, M. Crane
The symposium in context
The black-footed ferret (Mustela nigripes) is a member of the weasel family (Mustelidae) and is closely related to the Siberian polecat (M. eversmannii) of Asian steppes and the European polecat (M. putorius). Compared to its relatives, the black-footed ferret is an extreme specialist, depending on the prairie dogs (Cynomys spp.) of North American grasslands for food and using prairie dog burrows
Authors
Dean E. Biggins
The use of synthetic jarosite as an analog for natural jarosite
The presence of jarosite in soil or mining waste is an indicator of acidic sulfate-rich conditions. Physical and chemical properties of synthetic jarosites are commonly used as analogs in laboratory studies to determine solubility and acid-generation of naturally occurring jarosites. In our work we have mineralogically and chemically characterized both natural and synthetic jarosites. Analysis of
Authors
George A. Desborough, Kathleen S. Smith, Heather A. Lowers, Gregg A. Swayze, Jane M. Hammarstrom, Sharon F. Diehl, Rhonda L. Driscoll, Reinhard W. Leinz
The utility of gravity and magnetic methods for understanding subsurface hydrogeology in large alluvial watersheds: Examples from urbanized basins of the Western United States
Population continues to grow rapidly within the large alluvial watersheds associated with structural basins of the Basin and Range Province and the Rio Grande rift of the western United States. Increasing demands on ground‐water resources in these basins, combined with water‐rights disputes, have amplified the need for improved understanding of subsurface hydrogeology. Gravity and magnetic methods
Authors
V. J. S. Grauch, Victoria Langenheim
Towards sustainable management of Louisiana's coastal wetland forests: Problems, constraints, and a new beginning
Over 345,000 ha of forested swamps occur throughout the Mississippi River Deltaic Plain. Natural and anthropogenic changes in hydrology and geomorphology at local and landscape levels have reduced the productivity in many of these coastal wetland forests areas and have caused the complete loss of forest cover in some places. A summary and interpretation of the available science, suggestions for po
Authors
J. L. Chambers, W.H. Conner, R.F. Keim, S.P. Faulkner, J.W. Day, E.S. Gardiner, M.S. Hughes, S.L. King, K.W. McLeod, C.A. Miller, J.A. Nyman, G.P. Shaffer
Trends in the nutrient enrichment of U.S. rivers during the late 20th century and their relation to changes in probable stream trophic conditions
We estimated trends in concentrations of total phosphorus (TP) and total nitrogen (TN) and the related change in the probabilities of trophic conditions from 1975 to 1994 at 250 nationally representative riverine monitoring locations in the U.S. with drainage areas larger than about 1,000 km2. Statistically significant (p < 0.05) declines were detected in TP and TN concentrations at 44% and 37% of
Authors
R. B. Alexander, R. A. Smith
Uranium-series constraints on subrepository water flow at yucca mountain, nevada
Mineral abundances and whole-rock chemical and uranium-series isotopic compositions were measured in unfractured and rubble core samples from borehole USW SD-9 in the same layers of variably zeolitized tuffs that underlie the proposed nuclear waste repository at Yucca Mountain, Nevada. Uranium concentrations and isotopic compositions also were measured in pore water from core samples from the same
Authors
L.A. Neymark, S.J. Chipera, J.B. Paces, D. T. Vaniman
Use of the moon to support on-orbit sensor calibration for climate change measurements
Production of reliable climate datasets from multiple observational measurements acquired by remote sensing satellite systems available now and in the future places stringent requirements on the stability of sensors and consistency among the instruments and platforms. Detecting trends in environmental parameters measured at solar reflectance wavelengths (0.3 to 2.5 microns) requires on-orbit instr
Authors
T.C. Stone, H. H. Kieffer
Use of thermodynamic sorption models to derive radionuclide Kd values for performance assessment: Selected results and recommendations of the NEA sorption project
For the safe final disposal and/or long-term storage of radioactive wastes, deep or near-surface underground repositories are being considered world-wide. A central safety feature is the prevention, or sufficient retardation, of radionuclide (RN) migration to the biosphere. To this end, radionuclide sorption is one of the most important processes. Decreasing the uncertainty in radionuclide sorptio
Authors
M. Ochs, J.A. Davis, M. Olin, T.E. Payne, C.J. Tweed, M.M. Askarieh, S. Altmann