Thermodynamic properties of environmental arsenic species: Limitations and needs
D. Kirk Nordstrom
C. Young, editor(s)
2000, Book chapter, Minor elements 2000: Processing and environmental aspects of As, Sb, Se, Te, and Bi
No abstract available. ...
CFC tracing of groundwater in fractured rock aided with 14C and 3H to identify water mixing
A.S. Talma, John L. Weaver, L.N. Plummer, Eurybiades Busenberg
2000, Book chapter, Groundwater: Past achievements and future challenges
No abstract available. ...
Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district
Robert O. Rye, Philip M. Bethke, Marvin A. Lanphere, Thomas A. Steven
2000, GSA Special Papers (346) 95-103
K/Ar age determinations or supergene alunite and jarosite, formed during Neogene weathering of the epithermal silver and base-metal ores of the Creede mining district, have been combined with geologic evidence to estimate the timing of regional uplift of the southern Rocky Mountains and related canyon cutting. In addition, oxygen and...
Evolution of the Creede Caldera and its relation to mineralization in the Creede mining district, Colorado
Paul B. Barton, Robert O. Rye, Philip M. Bethke
2000, GSA Special Papers (346) 301-326
At 25 Ma a major epithermal silver and base metal deposit formed in rhyolitic welded tuff near Creede, Colorado. Nearly 24000 metric tons of silver, appreciable lead, and small amounts of zinc, copper, and gold, have been produced from large, crustified veins under Bachelor and Bulldog Mountains north and northwest...
Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository; Day 2, Beatty to Yucca Mountain; Stop 7B, Secondary minerals and paleohydrologic implications
Leonid A. Neymark, James B. Paces, Zell E. Peterman, B. M. Marshall, Joseph F. Whelan
2000, GSA Field Guides (2) 401-402
No abstract available. ...
The study of humic substances--In search of a paradigm
Robert L. Wershaw
G. Davis, E.A. Ghabbour, editor(s)
2000, Book chapter, Humic substances: Versatile components of plants, soils and water
No abstract available. ...
Selenium
Ronald S. Oremland
J. Ledenberg, editor(s)
2000, Book chapter, Encyclopedia of microbiology
No abstract available. ...
Modeling surface-subsurface hydrological interactions
Aaron I. Packman, Kenneth E. Bencala
Jeremy B. Jones, Patrick J. Mulholland, editor(s)
2000, Book chapter, Streams and ground waters
Nitrate isotopes in groundwater systems
Carol Kendall, Ramon Aravena
2000, Book chapter, Environmental tracers in subsurface hydrology
Nitrate contamination, often associated with agricultural activities, is a major problem in some shallow aquifers and is increasingly becoming a threat to groundwater supplies (Gillham and Cherry, 1978; Ronen et al., 1983; Spalding and Exner, 1991). The intake of high levels of nitrate can cause methemoglobinemia in infants, and...
Enhanced levels of zinc in drinking water adversely affect spatial learning in rats
J.M. Flinn, J. Morgan, J. Magaha, L. Krause, K. Navarrete, B.F. Jones
2000, Book chapter, Metal ions in biology and medicine
No abstract available....
Phosphate sorption by base metal hydroxides generated in the neutralization of acid mine drainage
P.L. Sibrell, P.R. Adler
2000, Conference Paper, Animal Feeding Operations: Effects on Hydrologic Resources and the Environment (USGS OFR 00-204)
No abstract available at this time...
Hydrological Aspects of Weather Prediction and Flood Warnings: Report of the Ninth Prospectus Development Team of the U.S. Weather Research Program
K.K. Droegemeier, J.D. Smith, S. Businger, C. Doswell III, J. Doyle, C. Duffy, E. Foufoula-Georgiou, T. Graziano, L.D. James, V. Krajewski, M. LeMone, D. Lettenmaier, C. Mass, R. Pielke Sr., P. Ray, S. Rutledge, J. Schaake, E. Zipser
2000, Conference Paper, Bulletin of the American Meteorological Society
Among the many natural disasters that disrupt human and industrial activity in the United States each year, including tornadoes, hurricanes, extreme temperatures, and lightning, floods are among the most devastating and rank second in the loss of life. Indeed, the societal impact of floods has increased during the past few...
Coupled atmosphere-biophysics-hydrology models for environmental modeling
R. L. Walko, L.E. Band, Jill Baron, T.G.F. Kittel, R. Lammers, T.J. Lee, D. Ojima, R.A. Pielke Sr., C. Taylor, C. Tague, C.J. Tremback, P.L. Vidale
2000, Journal of Applied Meteorology (39) 931-944
The formulation and implementation of LEAF-2, the Land Ecosystem–Atmosphere Feedback model, which comprises the representation of land–surface processes in the Regional Atmospheric Modeling System (RAMS), is described. LEAF-2 is a prognostic model for the temperature and water content of soil, snow cover, vegetation, and canopy air, and includes turbulent and...
Sensitivity of a high-elevation Rocky Mountain watershed to altered climate and CO2
Jill Baron, Melannie D. Hartman, L.E. Band, R.B. Lammers
2000, Water Resources Research (36) 89-99
We explored the hydrologic and ecological responses of a headwater mountain catchment, Loch Vale watershed, to climate change and doubling of atmospheric CO2 scenarios using the Regional Hydro-Ecological Simulation System (RHESSys). A slight (2°C) cooling, comparable to conditions observed over the past 40 years, led to greater snowpack and slightly...
Investigation of nitrogen transformations in a southern California constructed wastewater treatment wetland
J.J. Sartoris, J.S. Thullen, L. B. Barber, D.E. Salas
2000, Ecological Engineering (14) 49-65
A 9.9-ha combined habitat and wastewater treatment demonstration wetland was constructed and planted in the summer of 1994, at Eastern Municipal Water District’s (EMWD) Hemet/San Jacinto Regional Water Reclamation Facility (RWRF) in southern California. From January 1996 through September 1997, the marsh–pond–marsh wetland system was operated to polish an average...
Stream chemistry modeling of two watersheds in the Front Range, Colorado
Thomas Meixner, Roger C. Bales, Mark W. Williams, Donald H. Campbell, Jill S. Baron
2000, Water Resources Research (36) 77-87
We investigated the hydrologic, geochemical, and biogeochemical controls on stream chemical composition on the Green Lakes Valley and Andrews Creek watersheds using the alpine hydrochemical model (AHM). Both sites had comparable data sets from 1994 and 1996, including high‐resolution spatial data and high‐frequency time series of hydrology, geochemistry, and meteorology....
The significance of microbial processes in hydrogeology and geochemistry
F. H. Chapelle
2000, Hydrogeology Journal (8) 41-46
Microbial processes affect the chemical composition of groundwater and the hydraulic properties of aquifers in both contaminated and pristine groundwater systems. The patterns of water-chemistry changes that occur depend upon the relative abundance of electron donors and electron acceptors. In many pristine aquifers, where microbial metabolism is limited by the...
Fractionation of selenium isotopes during bacterial respiratory reduction of selenium oxyanions
M.J. Herbel, T.M. Johnson, R.S. Oremland, T.D. Bullen
2000, Geochimica et Cosmochimica Acta (64) 3701-3709
Reduction of selenium oxyanions by microorganisms is an important process in the biogeochemical cycling of selenium. Numerous bacteria can reduce Se oxyanions, which are used as electron acceptors during the oxidation of organic matter in anoxic environments. In this study, we used a double...
Hyporheic zone hydrological processes
K.E. Bencala
2000, Hydrological Processes (14) 2797-2798
No abstract available....
Water quality degradation effects on freshwater availability: Impacts of human activities
Norman E. Peters, Michel Meybeck
2000, Water International (25) 185-193
The quality of freshwater at any point on the landscape reflects the combined effects of many processes along water pathways. Human activities on all spatial scales affect both water quality and quantity. Alteration of the landscape and associated vegetation has not only changed the water balance, but typically has altered...
Habitat conservation and creation: Invoking the flood-pulse concept to enhance fisheries in the lower Mississippi River
H.L. Schramm Jr., M.A. Eggleton, R.M. Mayo
2000, Conference Paper, Polskie Archiwum Hydrobiologii
Analysis of four years of growth data failed to identify a single temperature or hydrologic variable that consistently accounted for variation in annual growth of catfishes (Ictaluridae). Instead, a composite variable that measured duration of floodplain inundation when water temperature exceeded minima for active feeding was directly related to growth....
Methyl-mercury degradation pathways: A comparison among three mercury impacted ecosystems
M. Marvin-DiPasquale, J. Agee, C. Mcgowan, R.S. Oremland, M. Thomas, D. Krabbenhoft, C.C. Gilmour
2000, Environmental Science & Technology (34) 4908-4916
We examined microbial methylmercury (MeHg) degradation in sediment of the Florida Everglades, Carson River (NV), and San Carlos Creek (CA), three freshwater environments that differ in the extent and type of mercury contamination and sediment biogeochemistry. Degradation rate constant (kdeg) values increased with total mercury (Hgt) contamination...
Transport of free and particulate-associated bacteria in karst
B.J. Mahler, J.-C. Personne, G.F. Lods, C. Drogue
2000, Journal of Hydrology (238) 179-193
Karst aquifers, because of their unique hydrogeologic characteristics, are extremely susceptible to contamination by pathogens. Here we present the results of an investigation of contamination of a karst aquifer by fecal indicator bacteria. Two wells intercepting zones with contrasting effective hydraulic conductivities, as determined by pump test, were monitored both...
Landscape-based spatially explicit species index models for everglades restoration
J. L. Curnutt, J. Comiskey, M.P. Nott, L.J. Gross
2000, Ecological Applications (10) 1849-1860
As part of the effort to restore the ∼10 000-km2 Everglades drainage in southern Florida, USA, we developed spatially explicit species index (SESI) models of a number of species and species groups. In this paper we describe the methodology and results of three such models: those for the Cape Sable Seaside Sparrow...
A dynamic landscape model for fish in the Everglades and its application to restoration
H.D. Gaff, D.L. DeAngelis, L.J. Gross, R. Salinas, M. Shorrosh
2000, Ecological Modelling (127) 33-52
A model (ALFISH) for fish functional groups in freshwater marshes of the greater Everglades area of southern Florida has been developed. Its main objective is to assess the spatial pattern of fish densities through time across freshwater marshes. This model has the capability of providing a dynamic measure of the...
