Tidal creek changes at the Sonoma Baylands restoration site
John R. Dingler, David A. Cacchione
Magoon O.T.Converse H.Baird B.Miller-Henson M., editor(s)
1998, Conference Paper, Proceedings of the Conference on California and the World Ocean
Over the past 150 years, human activity has had a major impact on tidal wetlands adjoining the San Francisco Bay-Delta estuary Growing concern about the effect of this change on the ecology of the estuary has prompted Bay area managers to attempt to reclaim tidal wetlands. The Sonoma Baylands Restoration...
Study-area boundary for "Structure, outcrop, and subcrop of the bedrock aquifers along the western margin of the Denver Basin, Colorado." Hydrologic Atlas 742
Sharon Rafferty
1998, Report
This digital geospatial data set consists of outlines of the study area in the report "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998)....
Location of wells shown in "Structure, outcrop,, and subcrop of the bedrock aquifers along the western margin of the Denver Basin, Colorado." Hydrologic Atlas 742
Sharon Rafferty
1998, Report
This digital geospatial data set consists of locations of coal, oil, gas and water wells shown as data points in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998)....
Feldspars as a source of nutrients for microorganisms
J.R. Rogers, P.C. Bennett, W.J. Choi
1998, American Mineralogist (83) 1532-1540
Phosphorus and nitrogen are essential macronutrients necessary for the survival of virtually all living organisms. In groundwater systems, these nutrients can be quite scarce and can represent limiting elements for growth of subsurface microorganisms. In this study we examined silicate sources of these elements by characterizing the colonization and weathering...
Nitrous oxide fluxes from a claypan soil overlying nitrate-enriched glacial drift
M.L. Pomes, D.H. Wilkison, P.B. McMahon
1998, Journal of Environmental Hydrology (6) 1-14
The closed chamber method was used to assess nitrous oxide (N2O) fluxes from corn (Zea mays, L.) fields during the 1995 growing season. The study area was characterized by a claypan soil overlying a nitrate (NO31-)-enriched glacial-drift aquifer. Denitrification produced N2O fluxes of 0.2-6.9 g ha-1 hr-1 early in the...
Interaction between stream temperature, streamflow, and groundwater exchanges in alpine streams
James E. Constantz
1998, Water Resources Research (34) 1609-1615
Four alpine streams were monitored to continuously collect stream temperature and streamflow for periods ranging from a week to a year. In a small stream in the Colorado Rockies, diurnal variations in both stream temperature and streamflow were significantly greater in losing reaches than in gaining reaches, with minimum streamflow...
Controls on denitrification in riparian soils in headwater catchments of a hardwood forest in the Catskill Mountains, U.S.A.
J.A. Ashby, W.B. Bowden, Peter S. Murdoch
1998, Soil Biology and Biochemistry (30) 853-864
Denitrification in riparian soils is thought to be an important factor that reduces hydrologic export of nitrate from forested and agricultural catchments. A 2-y study to identify the soil factors most closely associated with denitrification in riparian soils in headwater catchments within the Catskill Mountains of New York, included field...
Aqueous infrared carboxylate absorbances: Aliphatic di-acids
S.E. Cabaniss, J.A. Leenheer, I.F. McVey
1998, Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy (54) 449-458
Aqueous attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra of 18 aliphatic di-carboxylic acids are reported as a function of pH. The spectra show isosbestic points and intensity changes which indicate that Beer's law is obeyed, and peak frequencies lie within previously reported ranges for aqueous carboxylates and...
Tracing hydrologic pathways using chloride at the Panola mountain research watershed, Georgia, USA
N.E. Peters, E.B. Ratcliffe
1998, Water, Air, & Soil Pollution (105) 263-275
An analysis of chloride (Cl-) concentrations and fluxes at the 41 ha Panola Mountain Research Watershed indicates that Cl- may be used effectively to differentiate 'new' and 'old' water flow through the hillslope and their respective contributions to streamwater. Rainfall and throughfall, the 'new' water inputs, are marked by low...
Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events
L. V. Benson, S.P. Lund, J.W. Burdett, Michaele Kashgarian, T. P. Rose, J. P. Smoot, M. Schwartz
1998, Quaternary Research (49) 1-10
Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to...
Hydrogeologic studies at the USGS Amargosa Desert Research Site
Brian J. Andraski, David A. Stonestrom
Emily M. Taylor, editor(s)
1998, Book chapter, Quaternary geology of the Yucca Mountain area, southern Nevada: Field trip guide
In 1976, the U.S. Geological Survey (USGS) began studies of unsaturated-zone hydrology in the Amargosa Desert in support of the USGS Low-Level Radioactive Waste Program. In 1983, agreements with the Bureau of Land Management and the State of Nevada established two field study areas: a 16-ha area adjacent to a...
Multi-level slug tests in highly permeable formations: 1. Modification of the Springer-Gelhar (SG) model
V.A. Zlotnik, V. L. McGuire
1998, Journal of Hydrology (204) 271-282
A multi-level slug test model and a method for the evaluation of vertical profiles of hydraulic conductivity in highly permeable formations are developed. A double-packer system is employed to estimate local hydraulic conductivity. Depending on the formation and double-packer system parameters, the water level recovery in the tested well can...
Colloid particle sizes in the Mississippi River and some of its tributaries, from Minneapolis to below New Orleans
C.E. Rostad, T.F. Rees, S.R. Daniel
1998, Hydrological Processes (12) 25-41
An on-board technique was developed that combined discharge-weighted pumping to a high-speed continuous-flow centrifuge for isolation of the particulate-sized material with ultrafiltration for isolation of colloid-sized material. In order to address whether these processes changed the particle sizes during isolation, samples of particles in suspension were collected at various steps...
Simulated effects of irrigation on salinity in the Arkansas River Valley in Colorado
K. Goff, M.E. Lewis, M.A. Person, Leonard F. Konikow
1998, Ground Water (36) 76-86
Agricultural irrigation has a substantial impact on water quantity and quality in the lower Arkansas River valley of southeastern Colorado. A two-dimensional flow and solute transport model was used to evaluate the potential effects of changes in irrigation on the quantity and quality of water in the alluvial aquifer and...
AIRSLUG: A fortran program for the computation of type curves to estimate transmissivity and storativity from prematurely terminated air-pressurized slug tests
E.A. Greene, A.M. Shapiro
1998, Ground Water (36) 373-375
The Fortran code AIRSLUG can be used to generate the type curves needed to analyze the recovery data from prematurely terminated air-pressurized slug tests. These type curves, when used with a graphical software package, enable the engineer or scientist to analyze field tests to estimate transmissivity and storativity. Prematurely terminating...
Humic substances as a mediator for microbially catalyzed metal reduction
Derek R. Lovley, J.L. Fraga, E. L. Blunt-Harris, L.A. Hayes, Elizabeth J.P. Phillips, J.D. Coates
1998, Acta Hydrochimica et Hydrobiologica (26) 152-157
The potential for humic substances to serve as a terminal electron acceptor in microbial respiration and to function as an electron shuttle between Fe(III)‐reducing microorganisms and insoluble Fe(III) oxides was investigated. The Fe(III)‐reducing microorganism Geobacter metallireducens conserved energy to support growth from electron transport to humics as evidenced...
Multivariate classification of small order watersheds in the Quabbin Reservoir Basin, Massachusetts
R.M. Lent, M.C. Waldron, J. C. Rader
1998, Journal of the American Water Resources Association (34) 439-450
ABSTRACT: A multivariate approach was used to analyze hydrologic, geologic, geographic, and water-chemistry data from small order watersheds in the Quabbin Reservoir Basin in central Massachusetts. Eighty three small order watersheds were delineated and landscape attributes defining hydrologic, geologic, and geographic features of the watersheds were...
Effects of a beaver pond on runoff processes: comparison of two headwater catchments
Douglas A. Burns, Jeffery J. McDonnell
1998, Journal of Hydrology (205) 248-264
Natural variations in concentrations of 18O, D, and H4SiO4 in two tributary catchments of Woods Lake in the west-central Adirondack Mountains of New York were measured during 1989–1991 to examine runoff processes and their implications for the neutralization of acidic precipitation by calcium carbonate treatment. The two catchments are similar except that...
Field and laboratory evidence for intrinsic biodegradation of vinyl chloride contamination in a Fe(III)-reducing aquifer
P. M. Bradley, F. H. Chapelle, J.T. Wilson
1998, Journal of Contaminant Hydrology (31) 111-127
Intrinsic bioremediation of chlorinated ethenes in anaerobic aquifers previously has not been considered feasible, due, in large part, to 1) the production of vinyl chloride during microbial reductive dechlorination of higher chlorinated contaminants and 2) the apparent poor biodegradability of vinyl chloride under anaerobic conditions. In this study, a combination...
Effect of enhanced manganese oxidation in the hyporheic zone on basin-scale geochemical mass balance
Judson W. Harvey, Christopher C. Fuller
1998, Water Resources Research (34) 623-636
We determined the role of the hyporheic zone (the subsurface zone where stream water and shallow groundwater mix) in enhancing microbially mediated oxidation of dissolved manganese (to form manganese precipitates) in a drainage basin contaminated by copper mining. The fate of manganese is of overall importance to water quality in...
Bacterial methylmercury degradation in Florida Everglades peat sediment
M. C. Marvin-DiPasquale, R.S. Oremland
1998, Environmental Science & Technology (32) 2556-2563
Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently ≤0.1 d-1 and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were...
Uptake and loss kinetics of Cd, Cr and Zn in the bivalves Potamocorbula amurensis and Macoma balthica: Effects of size and salinity
B.-G. Lee, W.G. Wallace, S. N. Luoma
1998, Marine Ecology Progress Series (175) 177-189
...
Modeling tidal hydrodynamics of San Diego Bay, California
P.-F. Wang, R. T. Cheng, K. Richter, E.S. Gross, D. Sutton, J. W. Gartner
1998, Journal of the American Water Resources Association (34) 1123-1140
In 1983, current data were collected by the National Oceanic and Atmospheric Administration using mechanical current meters. During 1992 through 1996, acoustic Doppler current profilers as well as mechanical current meters and tide gauges were used. These measurements not only document tides and tidal currents in San Diego Bay, but...
Field study and simulation of diurnal temperature effects on infiltration and variably saturated flow beneath an ephemeral stream
Anne Dudek Ronan, David E. Prudic, Carl E. Thodal, Jim Constantz
1998, Water Resources Research (34) 2137-2153
Two experiments were performed to investigate flow beneath an ephemeral stream and to estimate streambed infiltration rates. Discharge and stream-area measurements were used to determine infiltration rates. Stream and subsurface temperatures were used to interpret subsurface flow through variably saturated sediments beneath the stream. Spatial variations in subsurface temperatures suggest...
Long-term hydrologic effects on marsh plant community structure in the southern Everglades
David E. Busch, W.F. Loftus, O. L. Bass Jr.
1998, Wetlands (18) 230-241
Although large-scale transformation of Everglades landscapes has occurred during the past century, the patterns of association among hydrologic factors and southern Everglades freshwater marsh vegetation have not been well-defined. We used a 10-year data base on the aquatic biota of Shark Slough to classify vegetation and describe plant community change...
