Numerical simulation of double‐diffusive finger convection
Joseph D. Hughes, Ward E. Sanford, H. Leonard Vacher
2005, Water Resources Research (41)
A hybrid finite element, integrated finite difference numerical model is developed for the simulation of double‐diffusive and multicomponent flow in two and three dimensions. The model is based on a multidimensional, density‐dependent, saturated‐unsaturated transport model (SUTRA), which uses one governing equation for fluid flow and another for solute transport. The...
Acquisition and evaluation of thermodynamic data for bieberite-moorhouseite equilibria at 0.1 MPa
I.-M. Chou, R.R. Seal II
2005, American Mineralogist (90) 912-917
Published estimates for the equilibrium relative humidity (RH) at 25 deg;C for the reaction: bieberite (CoSO4??7H2O) = moorhouseite (CoSO4??6H2O) + H2O, range from 69.8 to 74.5%. To evaluate these data, the humidity-buffer technique was used to determine equilibrium constants for this reaction between 14 and 43 ??C at 0.1 MPa....
Influence of sediment storage on downstream delivery of contaminated sediment
Daniel V. Malmon, Steven L. Reneau, Thomas Dunne, Danny Katzman, Paul G. Drakos
2005, Water Resources Research (41)
Sediment storage in alluvial valleys can strongly modulate the downstream migration of sediment and associated contaminants through landscapes. Traditional methods for routing contaminated sediment through valleys focus on in‐channel sediment transport but ignore the influence of sediment exchanges with temporary sediment storage reservoirs outside the channel, such as floodplains. In...
An empirical model for estimating annual consumption by freshwater fish populations
H. Liao, C.L. Pierce, J. G. Larscheid
2005, North American Journal of Fisheries Management (25) 525-532
Population consumption is an important process linking predator populations to their prey resources. Simple tools are needed to enable fisheries managers to estimate population consumption. We assembled 74 individual estimates of annual consumption by freshwater fish populations and their mean annual population size, 41 of which also included estimates of...
Analysis of ground-measured and passive-microwave-derived snow depth variations in midwinter across the Northern Great Plains
A.T.C. Chang, R.E.J. Kelly, E.G. Josberger, R.L. Armstrong, J.L. Foster, N. M. Mognard
2005, Journal of Hydrometeorology (6) 20-33
Accurate estimation of snow mass is important for the characterization of the hydrological cycle at different space and time scales. For effective water resources management, accurate estimation of snow storage is needed. Conventionally, snow depth is measured at a point, and in order to monitor snow depth in a temporally...
Decomposition rates and termite assemblage composition in semiarid Africa
Gregor Schuurman
2005, Ecology (86) 1236-1249
Outside of the humid tropics, abiotic factors are generally considered the dominant regulators of decomposition, and biotic influences are frequently not considered in predicting decomposition rates. In this study, I examined the effect of termite assemblage composition and abundance on decomposition of wood litter of an indigenous species (Croton megalobotrys)...
3H/3He age data in assessing the susceptibility of wells to contamination
Andrew H. Manning, D. Kip Solomon, Susan A. Thiros
2005, Ground Water (43) 353-367
Regulatory agencies are becoming increasingly interested in using young–ground water dating techniques, such as the 3H/3He method, in assessing the susceptibility of public supply wells (PSWs) to contamination. However, recent studies emphasize that ground water samples of mixed age may be the norm, particularly from long-screened PSWs, and tracer-based “apparent” ages...
Nitrogen controls on ecosystem carbon sequestration: a model implementation and application to Saskatchewan, Canada
J. Liu, D.T. Price, J.M. Chen
2005, Ecological Modelling (186) 178-195
A plant–soil nitrogen (N) cycling model was developed and incorporated into the Integrated BIosphere Simulator (IBIS) of Foley et al. [Foley, J.A., Prentice, I.C., Ramankutty, N., Levis, S., Pollard, D., Sitch, S., Haxeltine, A., 1996. An integrated biosphere model of land surface process, terrestrial carbon balance and vegetation dynamics. Global...
Reserve growth in oil fields of the North Sea
T. R. Klett, D. L. Gautier
2005, Petroleum Geoscience (11) 179-190
The assessment of petroleum resources of the North Sea, as well as other areas of the world, requires a viable means to forecast the amount of growth of reserve estimates (reserve growth) for discovered fields and to predict the potential fully developed sizes of undiscovered fields. This study investigates the...
Numerical modeling of an estuary: A comprehensive skill assessment
J.C. Warner, W.R. Geyer, J.A. Lerczak
2005, Journal of Geophysical Research C: Oceans (110) 1-13
Numerical simulations of the Hudson River estuary using a terrain-following, three-dimensional model (Regional Ocean Modeling System (ROMS)) are compared with an extensive set of time series and spatially resolved measurements over a 43 day period with large variations in tidal forcing and river discharge. The model is particularly effective at...
Nitrogen transport and transformations in a coastal plain watershed: Influence of geomorphology on flow paths and residence times
Anthony J. Tesoriero, Timothy B. Spruill, H.E. Mew Jr., Kathleen M. Farrell, Stephen L. Harden
2005, Water Resources Research (41) 1-15
Nitrogen transport and groundwater‐surface water interactions were examined in a coastal plain watershed in the southeastern United States. Groundwater age dates, calculated using chlorofluorocarbon and tritium concentrations, along with concentrations of nitrogen species and other redox‐active constituents, were used to evaluate the fate and transport of nitrate. Nitrate is stable...
A model for wave control on coral breakage and species distribution in the Hawaiian Islands
C. D. Storlazzi, E.K. Brown, M.E. Field, K. Rodgers, P. L. Jokiel
2005, Coral Reefs (24) 43-55
The fringing reef off southern Molokai, Hawaii, is currently being studied as part of a multi-disciplinary project led by the US Geological Survey. As part of this study, modeling and field observations were utilized to help understand the physical controls on reef morphology and the distribution of different coral species....
Topographic, bioclimatic, and vegetation characteristics of three ecoregion classification systems in North America: Comparisons along continent-wide transects
R.S. Thompson, S.L. Shafer, K. H. Anderson, L.E. Strickland, R.T. Pelltier, P. J. Bartlein, M.W. Kerwin
2005, Environmental Management (34)
Ecoregion classification systems are increasingly used for policy and management decisions, particularly among conservation and natural resource managers. A number of ecoregion classification systems are currently available, with each system defining ecoregions using different classification methods and different types of data. As a result, each classification system describes a unique...
Possible pingos and a periglacial landscape in northwest Utopia Planitia
R.J. Soare, D.M. Burr, Bun Tseung J.-M. Wan
2005, Icarus (174) 373-382
Hydrostatic (closed-system) pingos are small, elongate to circular, ice-cored mounds that are perennial features of some periglacial landscapes. The growth and development of hydrostatic pingos is contingent upon the presence of surface water, freezing processes and of deep, continuous, ice-cemented permafrost. Other cold-climate landforms such as small-sized, polygonal patterned ground...
Orientation of three-component geophones in the San Andreas Fault observatory at depth Pilot Hole, Parkfield, California
V. Oye, W.L. Ellsworth
2005, Bulletin of the Seismological Society of America (95) 751-758
To identify and constrain the target zone for the planned SAFOD Main Hole through the San Andreas Fault (SAF) near Parkfield, California, a 32-level three-component (3C) geophone string was installed in the Pilot Hole (PH) to monitor and improve the locations of nearby earthquakes. The orientation of the 3C geophones...
Differentiation of commercial vermiculite based on statistical analysis of bulk chemical data: Fingerprinting vermiculite from Libby, Montana U.S.A
M. E. Gunter, E. Singleton, B.R. Bandli, H.A. Lowers, G.P. Meeker
2005, American Mineralogist (90) 749-754
Major-, minor-, and trace-element compositions, as determined by X-ray fluorescence (XRF) analysis, were obtained on 34 samples of vermiculite to ascertain whether chemical differences exist to the extent of determining the source of commercial products. The sample set included ores from four deposits, seven commercially available garden products, and insulation...
Generation and validation of characteristic spectra from EO1 Hyperion image data for detecting the occurrence of the invasive species, Chinese tallow
Elijah W. Ramsey III, A. Rangoonwala, G. Nelson, R. Ehrlich, K. Martella
2005, International Journal of Remote Sensing (26) 1611-1636
Chinese tallow (Triadica sebifera) is an invasive tree that is spreading throughout the south-eastern United States and now into the west, and in many places causing extensive change to native habitat and associated wildlife. Detecting and mapping the relative distribution of this species is important to its control and eradication....
Probabilistic liquefaction triggering based on the cone penetration test
R.E.S. Moss, R.B. Seed, R. E. Kayen, J.P. Stewart, K. Tokimatsu
2005, Conference Paper, Geotechnical Special Publication
Performance-based earthquake engineering requires a probabilistic treatment of potential failure modes in order to accurately quantify the overall stability of the system. This paper is a summary of the application portions of the probabilistic liquefaction triggering correlations proposed recently proposed by Moss and co-workers. To enable probabilistic treatment of liquefaction...
High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation
W.C. Funk, A.E. Greene, P.S. Corn, F.W. Allendorf
2005, Biology Letters (1) 13-16
Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among...
Life history trade-offs and community dynamics of small fishes in a seasonally pulsed wetland
D.L. DeAngelis, J.C. Trexler, W.F. Loftus
2005, Conference Paper, Canadian Journal of Fisheries and Aquatic Sciences
We used a one-dimensional, spatially explicit model to simulate the community of small fishes in the freshwater wetlands of southern Florida, USA. The seasonality of rainfall in these wetlands causes annual fluctuations in the amount of flooded area. We modeled fish populations that differed from each other only in efficiency...
Relation of baseflow to row crop intensity in Iowa
K. E. Schilling
2005, Agriculture, Ecosystems and Environment (105) 433-438
Increasing baseflow and baseflow percentage over the second half of the 20th century in Iowa has contributed to increasing nitrate-nitrogen concentrations measured in Iowa rivers because nitrate is primarily delivered to streams as baseflow and tile drainage. The relation of baseflow and baseflow percentage to row crop land use was...
Single-pass versus two-pass boat electrofishing for characterizing river fish assemblages: Species richness estimates and sampling distance
M. R. Meador
2005, Transactions of the American Fisheries Society (134) 59-67
Determining adequate sampling effort for characterizing fish assemblage structure in nonwadeable rivers remains a critical issue in river biomonitoring. Two-pass boat electrofishing data collected from 500-1,000-m-long river reaches as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program were analyzed to assess the efficacy of single-pass boat electrofishing....
A whole image approach using field measurements for transforming EO1 Hyperion hyperspectral data into canopy reflectance spectra
Elijah W. Ramsey III, G. Nelson
2005, International Journal of Remote Sensing (26) 1589-1610
To maximize the spectral distinctiveness (information) of the canopy reflectance, an atmospheric correction strategy was implemented to provide accurate estimates of the intrinsic reflectance from the Earth Observing 1 (EO1) satellite Hyperion sensor signal. In rendering the canopy reflectance, an estimate of optical depth derived from a measurement of downwelling...
Mapping the invasive species, Chinese tallow, with EO1 satellite Hyperion hyperspectral image data and relating tallow occurrences to a classified Landsat Thematic Mapper land cover map
Elijah W. Ramsey III, A. Rangoonwala, G. Nelson, R. Ehrlich
2005, International Journal of Remote Sensing (26) 1637-1657
Our objective was to provide a realistic and accurate representation of the spatial distribution of Chinese tallow (Triadica sebifera) in the Earth Observing 1 (EO1) Hyperion hyperspectral image coverage by using methods designed and tested in previous studies. We transformed, corrected, and normalized Hyperion reflectance image data into composition images...
Influence of the Atchafalaya River on recent evolution of the chenier-plain inner continental shelf, northern Gulf of Mexico
A.E. Draut, G.C. Kineke, D.W. Velasco, M. A. Allison, R.J. Prime
2005, Continental Shelf Research (25) 91-112
This study examines the influence of the Atchafalaya River, a major distributary of the Mississippi River, on stratigraphic evolution of the inner continental shelf in the northern Gulf of Mexico. Sedimentary, geochemical, and shallow acoustic data are used to identify the western limit of the distal Atchafalaya subaqueous delta, and...
