Atmospheric deposition and solute export in giant sequoia: Mixed conifer watersheds in the Sierra Nevada, California
Thomas J. Stohlgren, John M. Melack, Anne M. Esperanza, David J. Parsons
1991, Biogeochemistry (12) 207-230
Atmospheric depostion and stream discharge and solutes were measured for three years (September 1984 — August 1987) in two mixed conifer watersheds in Sequoia National Park, in the southern Sierra Nevada of California. The Log Creek watershed (50 ha, 2067–2397 m elev.) is drained by a perennial stream, while Tharp's...
Structure and depositional patterns and their influence on the hydraulic conductivity of fan-deltas in southern Puerto Rico
Robert A. Renken, Fernando Gomez-Gomez, Vicente Quinones-Aponte, Rafael Dacosta
Fernando Gomez-Gomez, Vicente Quinones-Aponte, A.I. Johnson, editor(s)
1991, Conference Paper, Aquifers of the Caribbean Islands, Proceedings of the International Symposium on Tropical Hydrology
Preliminary analysis of the hydrologic and geochemical controls on acid‐neutralizing capacity in two acidic seepage lakes in Florida
Curtis D. Pollman, T. M. Lee, William J. Andrews, L. A. Sacks, S.A. Gherini, R.K. Munson
1991, Water Resources Research (27) 2321-2335
In late 1988, parallel studies of Lake Five‐O (pH 5.14) in the Florida panhandle and Lake Barco (pH 4.50) in north central Florida were initiated to develop hydrologic and major ion budgets of these lakes as part of an overall effort to improve understanding of the hydrologic, depositional, and biogeochemical...
Assessing the solubilities and reaction kinetics of aluminous minerals in soils
Howard M. May, D. Kirk Nordstrom
1991, Book chapter, Solid acidity
The use of chemical thermodynamics and reaction kinetics is necessary to quantitatively model the transformation of aluminous minerals and their dissolved constituents in soils and other geochemical systems. Soils are thermodynamically open systems subject to atmospheric and biological forces and do not attain overall thermodynamic equilibrium with respect to either...
Predicting the response of woody riparian vegetation to changes in instream flows through integrated monitoring of stream hydrology and riparian vegetation
M. L. Scott, L.J. Martin, Gregor T. Auble, C.A. Segelquist
1991, Report, South Platte River resource management: Finding a balance - Conference Proceedings
No abstract available....
Evaluation of unsaturated zone air permeability through pneumatic tests
Arthur L. Baehr, Marc F. Hult
1991, Water Resources Research (27) 2605-2617
Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air-phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the...
Hydrology of a riparian forested area on Boulder Creek
L.J. Martin
1991, Book, South Platte River resource management: Finding a balance
No abstract available....
Development of assessment methods for hydrologic impacts on western riparian ecosystems
Lee S. Ischinger
1991, Book, South Platte River resource management: Finding a balance
No abstract available....
Riparian vegetation of the Black Canyon of the Gunnison River, Colorado: composition and response to selected hydrologic regimes based on a direct gradient assessment model
Gregor T. Auble, Jonathan M. Friedman, Michael L. Scott
1991, Report
The Black Canyon of the Gunnison National Monument is located along the Gunnison River on the western slope of the Rocky Mountains in Montrose County, Colorado. The canyon is narrow because it is cut into resistant pre-Cambrian gneiss: it has a maximum depth of 900m and a minimum width of...
Effects of surfactants on the mobility of nonpolar organic contaminants in porous media
J. A. Smith, D. Tucker, P. R. Jaffe, R.T. Mueller
R. Baker, editor(s)
1991, Book chapter, Organic substances and sediments in water
No abstract available....
Response of plains cottonwood seeds and seedlings to simulated hydrologic regimes of the riparian zone
C.A. Segelquist
1991, Book, South Platte River resource management: Finding a balance
No abstract available....
A thermodynamic partition model for binding of nonionic organic compounds by organic colloids and implications for their sorption to soils and sediment
U.P. Chin, Walter J. Weber Jr., C. T. Chiou
R.A. Baker, editor(s)
1991, Book chapter, Organic substances and sediments in water: Humics and soils
No abstract available....
Parameters involved in modeling movement of bacteria in groundwater
Ronald W. Harvey
C. J. Hurst, editor(s)
1991, Book chapter, Modeling the environmental fate of microorganisms
No abstract available....
Particulate and colloidal organic material in Pueblo Reservoir, Colorado--Influence of autochthonous source on chemical composition
J. F. Ranville, R.A. Harnish, D.M. McKnight
R.A. Baker, editor(s)
1991, Book chapter, Organic substances and sediments in water
No abstract available. ...
The hydrogeologic framework of the Northern Coastal Province Aquifer System of Puerto Rico
Jesus Rodriguez-Martinez
Fernando Gomez-Gomez, Vicente Quinones-Aponte, A.I. Johnson, editor(s)
1991, Conference Paper, Aquifers of the Caribbean Islands, Proceedings of the International Symposium on Tropical Hydrology
New hydrologic instrumentation in the U.S. Geological Survey
V.J. Latkovich, W.G. Shope
Sodhi Devinder S., editor(s)
1991, Conference Paper, Cold Regions Engineering
New water-level sensing and recording instrumentation is being used by the U.S. Geological Survey for monitoring water levels, stream velocities, and water-quality characteristics. Several of these instruments are briefly described. The Basic Data Recorder (BDR) is an electronic data logger, that interfaces to sensor systems through a serial-digital interface standard...
Reduction of nitrate in aquifer microcosms by carbon additions
Donald C. Obenhuber, Richard Lowrance
1991, Journal of Environmental Quality (20) 255-258
Aquifer microcosms were used to examine the effects of NO−3 and C amendments on groundwater from the Claiborne aquifer. Nitrate concentrations of 12.17 mg L−1 in aquifer microcosms were reduced 0.92%/d to 5.84 mg L−1 by the addition of 10 mg C L−1 for 35 d. Nitrate disappearance correlated with...
Flame ionization mass spectrometry--Isotope ratio determinations for potassium
Howard E. Taylor, John R. Garbarino, S. R. Koirtyohann
1991, Applied Spectroscopy (45) 886-886
The air/acetylene flame provides a convenient ion source for the determination of potassium isotopic ratios by mass spectrometry. Unlike the argon inductively coupled plasma (ICP), the flame provides low background in the mass region of interest. Ion production is quite satisfactory for isotope ratio measurements at the micrograms per milliliter...
Simulation of vertical compaction in models of regional ground-water flow
S. A. Leake
Anon, editor(s)
1991, Conference Paper, IAHS Publication (International Association of Hydrological Sciences)
A new computer program was developed to simulate vertical compaction in models of regional ground-water flow. The program accounts for ground-water storage changes and compaction in discontinuous interbeds or in extensive confining beds. The new program is a package for the U.S. Geological Survey modular finite-difference ground-water flow model. Several...
Disturbance effects on aquatic vegetation in regulated and unregulated lakes in northern Minnesota
Douglas A. Wilcox, James E. Meeker
1991, Canadian Journal of Botany (69) 1542-1551
The effects of water-level regulation on aquatic macrophyte communities were investigated by comparing two regulated lakes in northern Minnesota with a nearby unregulated lake (Lac La Croix). Natural annual fluctuations of about 1.8 m were replaced with fluctuations of 1.1 m and 2.7 m in the regulated lakes, and the...
Formation and transport of deethylatrazine in the soil and vadose zone
C.D. Adams, E.M. Thurman
1991, Journal of Environmental Quality (20) 540-547
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and two degradation products were monitored at seven depths in the soil and vadose zone throughout the growing season in two experimental plots in which corn (Zea mays L.) was grown. The soils in these plots were a Kimo silty clay loam (clayey over loamy, montmorillonitic, mesic, Fluvaquentic...
Solution of the one-dimensional consolidation theory equation with a pseudospectral method
N. Sepulveda
Anon, editor(s)
1991, Conference Paper, IAHS Publication (International Association of Hydrological Sciences)
The one-dimensional consolidation theory equation is solved for an aquifer system using a pseudospectral method. The spatial derivatives are computed using Fast Fourier Transforms and the time derivative is solved using a fourth-order Runge-Kutta scheme. The computer model calculates compaction based on the void ratio changes accumulated during the simulated...
Fate of silicate minerals in a peat bog
Philip C. Bennett, Donald I. Siegel, Barbara M. Hillier, Paul H. Glaser
1991, Geology (19) 328-331
An investigation of silicate weathering in a Minnesota mire indicates that quartz and aluminosilicates rapidly dissolve in anoxic, organic-rich, neutral- pH environments. Vertical profiles of pH, dissolved silicon, and major cations were obtained at a raised bog and a spring fen and compared. Profiles of readily extractable silicon, diatom...
Compilation of hydrologic data for the Edwards aquifer, San Antonio area, Texas, 1990, with 1934–90 summary
D.S. Brown, Jon R. Gilhousen, G.M. Nalley
1991, Edwards Underground Water District Bulletin 50
No abstract available....
Response of Ned Wilson Lake watershed, Colorado, to changes in atmospheric deposition of sulfate
Donald H. Campbell, John T. Turk, Norman E. Spahr
1991, Water Resources Research (27) 2047-2060
The Ned Wilson Lake watershed responds directly and rapidly to changes in precipitation inputs of sulfate, which has important implications for effects of acid deposition on the aquatic system. Chemistry at three precipitation collection sites and three watershed sites (a pond, a lake, and a spring) has been monitored in...
