Year-to-year fluctuation of the spring phytoplankton bloom in south San Francisco Bay: An example of ecological variability at the land-sea interface
James E. Cloern, Alan D. Jassby
1995, Book chapter, Ecological time
Estuaries are transitional ecosystems at the interface of the terrestrial and marine realms. Their unique physiographic position gives rise to large spatial variability, and to dynamic temporal variability resulting, in part, from a variety of forces and fluxes at the oceanic and terrestrial boundaries. River flow, in particular, is an...
The global topography mission gains momentum
Tom Farr, Diane Evans, Howard Zebker, David Harding, Jack Bufton, Timothy Dixon, S. Vetrella, Dean B. Gesch
1995, Eos, Transactions, American Geophysical Union (76) 213-216
An accurate description of the surface elevation of the Earth is of fundamental importance to many branches of Earth science. Continental topographic data are required for studies of hydrology, ecology, glaciology, geomorphology, and atmospheric circulation. For example, in hydrologic and terrestrial ecosystem studies, topography exerts significant control on intercepted solar...
Hydrological processes and the water budget of lakes
Thomas C. Winter
Abraham Lerman, Dieter M. Imboden, Joel R. Gat, editor(s)
1995, Book chapter, Physics and chemistry of lakes
Lakes interact with all components of the hydrological system: atmospheric water, surface water, and groundwater. The fluxes of water to and from lakes with regard to each of these components represent the water budget of a lake. Mathematically, the concept of a water budget is deceptively simple: income equals outgo,...
Wetland and aquatic macrophytes as indicators of anthropogenic hydrologic disturbance
Douglas A. Wilcox
1995, Natural Areas Journal (15) 240-248
Hydrologic disturbance can affect wetland and aquatic macrophyte communities by creating temporal changes in soil moisture or water depth. Such disturbances are natural and help maintain wetland diversity; however, anthropogenic changes in wetland hydrology may have negative effects on wetlands. Since plant communities respond to habitat alterations, observations...
Estimating shallow subsidence in microtidal salt marshes of the southeastern United States: Kaye and Barghoorn revisited
Donald R. Cahoon, D.J. Reed, J.W. Day Jr.
1995, Marine Geology (128) 1-9
Simultaneous measurements of vertical accretion and change in surface elevation relative to a shallow (3-5 m) subsurface datum were made in selected coastal salt marshes of Louisiana, Florida, and North Carolina to quantitatively test Kaye and Barghoorn's contention that vertical accretion is not a good surrogate for surface elevation change...
Hydrologic effects of increased urbanization
Joel R. Guay
Espey William H.Combs Phil G., editor(s)
1995, Conference Paper, International Water Resources Engineering Conference - Proceedings
Urban areas in Perris Valley, California, have more than tripled during the last 20 years, resulting in increased storm-runoff volumes and peak discharges. To quantify the effects of increased urbanization, rainfall-runoff models of the basin were developed to simulate runoff for 1970-75 and 1990-93 conditions. Hourly rainfall data for 1949-93...
Fluxes of water and solute in a coastal wetland sediment. l. The contribution of regional groundwater discharge
William K. Nuttle, Judson W. Harvey
1995, Journal of Hydrology (164) 89-107
Upward discharge of fresh groundwater into a mid-Atlantic intertidal wetland contributed 62% of the water needed to replace evapotranspiration losses from the sediment during an 11 day period in September. Infiltration during flooding by tides provided most of the balance; thus there was a net advection of salt into the...
Mapping the response of riparian vegetation to possible flow reductions in the Snake River, Idaho
W. Carter Johnson, Mark D. Dixon, Robert W. Simons, Susan Jenson, Kevin Larson
1995, Geomorphology (13) 159-173
This study was initiated to determine the general effects of potential flow reductions in the middle Snake River (Swan Falls Dam downstream to the Idaho-Oregon border) on its riparian vegetation. Considerable water from the river is currently used to irrigate the adjacent Snake River Plain, and increased demand for water...
A computer model of long-term salinity in San Francisco Bay: Sensitivity to mixing and inflows
R.J. Uncles, D. H. Peterson
1995, Environment International (21) 647-656
A two-level model of the residual circulation and tidally-averaged salinity in San Francisco Bay has been developed in order to interpret long-term (days to decades) salinity variability in the Bay. Applications of the model to biogeochemical studies are also envisaged. The model has been used to simulate daily-averaged salinity in...
Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction
Cathy M. Tate, Robert E. Broshears, Diane M. McKnight
1995, Limnology and Oceanography (40) 938-946
Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate (32P0,) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix...
Transport behavior of groundwater protozoa and protozoan-sized microspheres in sandy aquifer sediments
R.W. Harvey, N.E. Kinner, A. Bunn, Duncan MacDonald, D. Metge
1995, Applied and Environmental Microbiology (61) 209-217
Transport behaviors of unidentified flagellated protozoa (flagellates) and flagellate-sized carboxylated microspheres in sandy, organically contaminated aquifer sediments were investigated in a small-scale (1 to 4-m travel distance) natural-gradient tracer test on Cape Cod and in flow-through columns packed with sieved (0.5-to 1.0-mm grain size) aquifer sediments. The minute (average...
Pb2+ and Zn2+ adsorption by a natural aluminum- and iron-bearing surface coating on an aquifer sand
J.A. Coston, C. C. Fuller, J.A. Davis
1995, Geochimica et Cosmochimica Acta (59) 3535-3547
Pb2+ and Zn2+ adsorption was studied in batch experiments with material collected from a shallow, unconfined aquifer of glacial outwash sand and gravel in Falmouth, Massachusetts, USA. The aquifer solids contain primarily quartz (95% w/w), with minor amounts of alkali feldspars and ferromagnetic minerals. Pb2+ and...
Frequent outburst floods from South Tahoma Glacier, Mount Rainier, USA: Relation to debris flows, meteorological origin, and implications for subglacial hydrology
J. S. Walder, C. L. Driedger
1995, Journal of Glaciology (41) 1-10
Destructive debris flows occur frequently at glacierized Mount Rainier volcano, Washington, U.S.A. Twenty-three such flows have occurred in the Tahoma Creek valley since 1967. Hydrologic and geomorphic evidence indicate that all or nearly all of these flows began as outburst floods from South Tahoma Glacier. Flood waters...
Fluxes of water and solute in a coastal wetland sediment. 2. Effect of macropores on solute exchange with surface water
J. W. Harvey, W.K. Nuttle
1995, Journal of Hydrology (164) 109-125
Chloride was highly concentrated relative to seawater in matrix porewater but was comparatively dilute in macropores. Concentration differences in pore-size classes declined with depth until indistinguishable below 10 cm. The segregated chloride distribution can be explained if recharge to the sediment occurred by downward infiltration in macropores and discharge occurred...
Preferential flow and segregation of porewater solutes in Wetland sediment
J. W. Harvey, R.M. Chambers, J.R. Hoelscher
1995, Estuaries (18) 568-578
Sediment macropores (with effective diameters larger than 100 ??m) comprise 11% of the bulk sediment volume in a tidal freshwater wetland vegetated with Peltandra virginica. In order to determine effects of macroporous sediment structure on solute transport, we conducted a solute tracer experiment in the sediment. The effective transport volume...
Determination of water retention in stratified porous materials
J. Constantz
1995, Transport in Porous Media (18) 217-229
Predicted and measured water-retention values,θ(ψ), were compared for repacked, stratified core samples consisting of either a sand with a stone-bearing layer or a sand with a clay loam layer in various spatial orientations. Stratified core samples were packed in submersible pressure outflow cells, then water-retention...
Fate of microbial metabolites of hydrocarbons in a coastal plain aquifer: The role of electron acceptors
I.M. Cozzarelli, J.S. Herman, M. Jo Baedecker
1995, Environmental Science & Technology (29) 458-469
A combined field and laboratory study was undertaken to understand the distribution and geochemical conditions that influence the prevalence of low molecular weight organic acids in groundwater of a shallow aquifer contaminated with gasoline. Aromatic hydrocarbons from gasoline were degraded by microbially mediated oxidation-reduction reactions, including reduction of nitrate, sulfate,...
Use of the euryhaline bivalve Potamocorbula amurensis as a biosentinel species to assess trace metal contamination in San Francisco Bay
C. L. Brown, S. N. Luoma
1995, Marine Ecology Progress Series (124) 129-142
Potamocorbula amurensis was assessed as a biosentinel species in San Francisco Bay, California, USA. Uptake of metal in both the laboratory and field showed that P. amurensis was sufficiently responsive to Ag, Cd, Cr, Ni and V to detect environmental differences in exposure. It was less suitable as an indicator of Cu...
Growth of strain SES-3 with arsenate and other diverse electron acceptors
A.M. Laverman, J.S. Blum, J.K. Schaefer, Elizabeth J.P. Phillips, Derek R. Lovley, R.S. Oremland
1995, Applied and Environmental Microbiology (61) 3556-3561
The selenate-respiring bacterial strain SES-3 was able to use a variety of inorganic electron acceptors to sustain growth. SES-3 grew with the reduction of arsenate to arsenite, Fe(III) to Fe(II), or thiosulfate to sulfide. It also grew in medium in which elemental sulfur, Mn(IV), nitrite, trimethylamine N-oxide, or fumarate was...
Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 2. Major structures
J.A. Leenheer, R.L. Wershaw, M.M. Reddy
1995, Environmental Science & Technology (29) 399-405
Polycarboxylic acid structures that account for the strong-acid characteristics (pKa1 near 2.0) were examined for fulvic acid from the Suwannee River. Studies of model compounds demonstrated that pKa values near 2.0 occur only if the a-ether or a-ester groups were in cyclic structures with two to three additional electronegative functional...
Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 1. Minor structures
J.A. Leenheer, R.L. Wershaw, M.M. Reddy
1995, Environmental Science & Technology (29) 393-398
An investigation of the strong-acid characteristics (pKa 3.0 or less) of fulvic acid from the Suwannee River, Georgia, was conducted. Quantitative determinations were made for amino acid and sulfur-containing acid structures, oxalate half-ester structures, malonic acid structures, keto acid structures, and aromatic carboxyl-group structures. These determinations were made by using...
Hydrogen and oxygen isotopic compositions of waters from fumaroles at Kilauea summit, Hawaii
T. K. Hinkley, J. E. Quick, R. T. Gregory, T.M. Gerlach
1995, Bulletin of Volcanology (57) 44-51
Condensate samples were collected in 1992 from a high-temperature (300° C) fumarole on the floor of the Halemaumau Pit Crater at Kilauea. The emergence about two years earlier of such a hot fumarole was unprecedented at such a central location at Kilauea. The condensates have hydrogen and oxygen isotopic compositions...
Hydrochemical processes during snowmelt in a subalpine watershed, Colorado, USA
N.E. Peters, G.H. Leavesley
1995, Biogeochemistry of seasonally snow-covered catchments. Proc. symposium, Boulder, 1995 (228) 313-319
Snowmelt is the primary hydrologic event in the studied subalpine watershed, generating streamflow for 3 months from a 1-month snowmelt period which commenced in mid-April 1992 and mid-May 1993. The melting rate of the snowpack varied diurnally and was asymmetrical, increasing rapidly to a maximum at the onset of daily...
Use of hydrologic budgets and hydrochemistry to determine ground-water and surface-water interactions for Rapid Creek, Western South Dakota
Mark T. Anderson
1995, Conference Paper, International Symposium on Groundwater Management - Proceedings
The study of ground-water and surface-water interactions often employs streamflow-gaging records and hydrologic budgets to determine ground-water seepage. Because ground-water seepage usually is computed as a residual in the hydrologic budget approach, all uncertainty of measurement and estimation of budget components is associated with the ground-water seepage. This uncertainty can...
Little River revisited - thirty-five years after Hack and Goodlett
W. R. Osterkamp, C.R. Hupp, M.R. Schening
1995, Geomorphology (13) 1-20
In possibly the first detailed study to relate geomorphology, vegetation, and hydrology at a watershed scale, Hack and Goodlett (1960) documented variation in the eastern forest with topograhic positions of cove, side slope, and nose. Runoff identified as convergent, parallel, or divergent,...
