Effects of tidal shallowing and deepening on phytoplankton production dynamics: A modeling study
L.V. Lucas, J. E. Cloern
2002, Estuaries (25) 497-507
Processes influencing estuarine phytoplankton growth occur over a range of time scales, but many conceptual and numerical models of estuarine phytoplankton production dynamics neglect mechanisms occurring on the shorter (e.g., intratidal) time scales. We used a numerical model to explore the influence of short time-scale variability in phytoplankton sources and...
A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates
P.A. Maurice, M.J. Pullin, S.E. Cabaniss, Q. Zhou, K. Namjesnik-Dejanovic, G. R. Aiken
2002, Water Research (36) 2357-2371
This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the...
Interannual variations in snowpack in the Crown of the Continent Ecosystem
D.J. Selkowitz, D.B. Fagre, B.A. Reardon
2002, Hydrological Processes (16) 3651-3665
Ecosystem changes such as glacier recession and alpine treeline advance have been documented over the previous 150 years in the Rocky Mountains of northern Montana and southern British Columbia and Alberta, a region known as the Crown of the Continent Ecosystem (CCE). Such changes are controlled, at least partially, by...
Leisingera methylohalidivorans gen. nov., sp. nov., a marine methylotroph that grows on methyl bromide
J.K. Schaefer, K.D. Goodwin, I.R. McDonald, J.C. Murrell, Ronald S. Oremland
2002, International Journal of Systematic and Evolutionary Microbiology (52) 851-859
A marine methylotroph, designated strain MB2T, was isolated for its ability to grow on methyl bromide as a sole carbon and energy source. Methyl chloride and methyl iodide also supported growth, as did methionine and glycine betaine. A limited amount of growth was observed with dimethyl sulfide. Growth was also...
Characterization of microbial arsenate reduction in the anoxic bottom waters of Mono Lake, California
S.E. Hoeft, F. Lucas, J.T. Hollibaugh, R.S. Oremland
2002, Geomicrobiology Journal (19) 23-40
Dissimilatory reduction of arsenate (DAsR) occurs in the arsenic-rich, anoxic water column of Mono Lake, California, yet the microorganisms responsible for this observed in situ activity have not been identified. To gain insight as to which microorganisms mediate this phenomenon, as well as to some of the biogeochemical constraints on...
Binding of mercury(II) to dissolved organic matter: The role of the mercury-to-DOM concentration ratio
M. Haitzer, G. R. Aiken, J. N. Ryan
2002, Environmental Science & Technology (36) 3564-3570
The binding of Hg(II) to dissolved organic matter (DOM; hydrophobic acids isolated from the Florida Everglades by XAD-8 resin) was measured at a wide range of Hg-to-DOM concentration ratios using an equilibrium dialysis ligand exchange method. Conditional distribution coefficients (KDOM‘) determined...
Using chemical, hydrologic, and age dating analysis to delineate redox processes and flow paths in the riparian zone of a glacial outwash aquifer‐stream system
Larry J. Puckett, Timothy K. Cowdery, Peter B. McMahon, Lan H. Tornes, Jeffrey D. Stoner
2002, Water Resources Research (38) 9-1-9-20
A combination of chemical and dissolved gas analyses, chlorofluorocarbon age dating, and hydrologic measurements were used to determine the degree to which biogeochemical processes in a riparian wetland were responsible for removing NO3−from groundwaters discharging to the Otter Tail River in west central Minnesota. An analysis of river chemistry and...
Assessment of metal loads in watersheds affected by acid mine drainage by using tracer injection and synoptic sampling: Cement Creek, Colorado, USA
B. A. Kimball, R.L. Runkel, K. Walton-Day, K.E. Bencala
2002, Applied Geochemistry (17) 1183-1207
Watersheds in mineralized zones may contain many mines, each of which can contribute to acidity and the metal load of a stream. In this study the authors delineate hydrogeologic characteristics determining the transport of metals from the watershed to the stream in the watershed...
Rangeland health attributes and indicators for qualitative assessment
David A. Pyke, Jeffrey E. Herrick, Patrick Shaver, Mike Pellant
2002, Journal of Range Management (55) 584-597
Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a...
Grid-cell-based crop water accounting for the famine early warning system
J. Verdin, R. Klaver
2002, Hydrological Processes (16) 1617-1630
Rainfall monitoring is a regular activity of food security analysts for sub-Saharan Africa due to the potentially disastrous impact of drought. Crop water accounting schemes are used to track rainfall timing and amounts relative to phenological requirements, to infer water limitation impacts on yield. Unfortunately, many rain gauge reports are...
Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99
M. E. Brigham, D. P. Krabbenhoft, M.L. Olson, J.F. DeWild
2002, Water, Air, & Soil Pollution (138) 61-78
We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early...
Drainage reversals in Mono Basin during the late pliocene and Pleistocene
M.C. Reheis, S. Stine, A.M. Sarna-Wojcicki
2002, Geological Society of America Bulletin (114) 991-1006
Mono Basin, on the eastern flank of the central Sierra Nevada, is the highest of the large hydrographically closed basins in the Basin and Range province. We use geomorphic features, shoreline deposits, and basalt-filled paleochannels to reconstruct an early to middle Pleistocene record of shorelines and changing spillways of Lake...
Effects of canopy gaps and flooding on homopterans in a bottomland hardwood forest
L.E. Gorham, S.L. King, B. D. Keeland, S. Mopper
2002, Wetlands (22) 541-549
Canopy disturbance is a major factor affecting forest structure and composition and, as a result of habitat alterations, can influence insect communities. We initiated a field study to quantify the effects of canopy disturbance on aerial insect abundance and distribution within a bottomland hardwood forest along the Cache River, Arkansas,...
Crosswell seismic investigation of hydraulically conductive, fracture bedrock near Mirror Lake, New Hampshire
K.J. Ellefsen, P. A. Hsieh, A.M. Shapiro
2002, Journal of Applied Geophysics (50) 299-317
Near Mirror Lake, New Hampshire (USA), hydraulically conductive, fractured bedrock was investigated with the crosswell seismic method to determine whether this method could provide any information about hydraulic conductivity between wells. To this end, crosswell seismic data, acoustic logs from boreholes, image logs from...
Nutrient limitation, hydrology and watershed nitrogen loss
Steven S. Perakis
2002, Hydrological Processes (16) 3507-3511
No abstract available....
Using groundwater levels to estimate recharge
R. W. Healy, P.G. Cook
2002, Hydrogeology Journal (10) 91-109
Accurate estimation of groundwater recharge is extremely important for proper management of groundwater systems. Many different approaches exist for estimating recharge. This paper presents a review of methods that are based on groundwater-level data. The water-table fluctuation method may be the most widely used technique for estimating recharge; it requires...
Topographic stress perturbations in southern Davis Mountains, west Texas 2. Hydrogeologic implications
R. H. Morin, W. Z. Savage
2002, Journal of Geophysical Research B: Solid Earth (107) ETG 6-1-ETG 6-10
As part of a regional groundwater investigation, geophysical logs were obtained in two municipal water wells located near the west Texas city of Alpine. These boreholes are 252 and 285 m deep and penetrate extrusive rocks of Tertiary age. The deeper well was drilled in the central valley and the...
Spatial and statistical differences between 1:250,000- and 1:24,000-scale digital soil databases
K. E. Juracek, D.M. Wolock
2002, Journal of Soil and Water Conservation (57) 89-94
In this study, 1:250,000- and 1:24,000-scale digital soil databases for Kansas were compared statistically and spatially. The soil attributes used in this comparison were soil permeability, percent clay, and hydrologic group. Results indicate that, although the two databases were correlated, the potential exists for substantial site-specific variability between them. The...
Influence of hydrologic processes on reproduction of the introduced bivalve Potamocorbula amurensis in northern San Francisco Bay, California
Francis Parchaso, Janet K. Thompson
2002, Pacific Science (56) 329-345
Monthly censusing of reproductive condition of the Asian clam Potamocorbula amurensis at four sites in northern San Francisco Bay over a 9-yr period revealed year-to-year differences in local reproductive activity that are associated with patterns of hydrologic variability. Between 1989 and 1992, Northern California experienced a drought, whereas the period between 1993...
Measuring streamflow in Virginia (2002 revision)
Roger M. Moberg, Karen C. Rice, Eugene D. Powell
2002, Open-File Report 95-713
The U.S. Geological Survey (USGS), U.S. Department of the Interior, is the Nation's largest Earth-science information agency. Among its many responsibilities, such as map making and providing information on earthquakes and other natural hazards, the USGS provides information on the Nation's water resources. The USGS has collected and analyzed hydrologic...
Water-quality data for pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000
Kimberlee K. Barnes, Dana W. Kolpin, Michael T. Meyer, E. Michael Thurman, Edward T. Furlong, Steven D. Zaugg, Larry B. Barber
2002, Open-File Report 2002-94
Water-quality data collected during 1999 and 2000 as part of the first nationwide reconnaissance of the occurrence of pharmaceuticals, hormones, and other organic wastewater contaminants (OWCs) are presented in this report. A network of 139 streams in 30 states were sampled and analyzed for 95 different OWCs using five new...
Environmental Characteristics and Geographic Information System Applications for the Development of Nutrient Thresholds in Oklahoma Streams
Jason R. Masoner, Brian E. Haggard, Alan Rea
2002, Water-Resources Investigations Report 2002-4191
The U.S.Environmental Protection Agency has developed nutrient criteria using ecoregions to manage and protect rivers and streams in the United States. Individual states and tribes are encouraged by the U.S. Environmental Protection Agency to modify or improve upon the ecoregion approach. The Oklahoma Water Resources Board uses a dichotomous process...
SUTRA: A model for 2D or 3D saturated-unsaturated, variable-density ground-water flow with solute or energy transport
Clifford I. Voss, A.M. Provost
2002, Water-Resources Investigations Report 2002-4231
SUTRA (Saturated-Unsaturated Transport) is a computer program that simulates fluid movement and the transport of either energy or dissolved substances in a subsurface environment. This upgraded version of SUTRA adds the capability for three-dimensional simulation to the former code (Voss, 1984), which allowed only two-dimensional simulation. The code employs a...
Flux of dissolved forms of mercury across the sediment-water interface in Lahontan Reservoir, Nevada
James S. Kuwabara, Mark Marvin-DiPasquale, Wayne Praskins, Earl Byron, Brent R. Topping, James L. Carter, Steven V. Fend, Francis Parcheso, David P. Krabbenhoft, Mae S. Gustin
2002, Water-Resources Investigations Report 2002-4138
No abstract available....
Lake belt study area: High-resolution seismic-reflection survey, Miami-Dade County Florida
Jack L. Kindinger
2002, Open-File Report 2002-325
Executive Summary The Northwest Dade County Freshwater Lake Plan Area (commonly referred to as the Lake Belt Area) is vital to the future planning and development of southeastern Florida. This area is located within one of the most environmentally sensitive parts of the state – the eastern borders of the...
