Targeting land-use change for nitratenitrogen load reductions in an agricultural watershed
M.K. Jha, K. E. Schilling, Philip W. Gassman, C.F. Wolter
2010, Journal of Soil and Water Conservation (65) 342-352
The research was conducted as part of the USDA's Conservation Effects Assessment Project. The objective of the project was to evaluate the environmental effects of land-use changes, with a focus on understanding how the spatial distribution throughout a watershed influences their effectiveness.The Soil and Water AssessmentTool (SWAT) water quality model...
An approach to quantify sources, seasonal change, and biogeochemical processes affecting metal loading in streams: Facilitating decisions for remediation of mine drainage
B. A. Kimball, R.L. Runkel, K. Walton-Day
2010, Applied Geochemistry (25) 728-740
Historical mining has left complex problems in catchments throughout the world. Land managers are faced with making cost-effective plans to remediate mine influences. Remediation plans are facilitated by spatial mass-loading profiles that indicate the locations of metal mass-loading, seasonal changes, and the extent of biogeochemical processes. Field-scale experiments during both...
Mapping of road-salt-contaminated groundwater discharge and estimation of chloride load to a small stream in southern New Hampshire, USA
P. T. Harte, P.R. Trowbridge
2010, Hydrological Processes (24) 2349-2368
Concentrations of chloride in excess of State of New Hampshire water-quality standards (230 mg/l) have been measured in watersheds adjacent to an interstate highway (I-93) in southern New Hampshire. A proposed widening plan for I-93 has raised concerns over further increases in chloride. As part of this effort, road-salt-contaminated groundwater...
The quixotic search for a comprehensive understanding of hydrologic response at the surface: Horton, Dunne, Dunton, and the role of concept-development simulation
K. Loague, C.S. Heppner, B.A. Ebel, J.E. VanderKwaak
2010, Hydrological Processes (24) 2499-2505
[No abstract available]...
Organic intermediates in the anaerobic biodegradation of coal to methane under laboratory conditions
William H. Orem, Mary A. Voytek, Elizabeth J. Jones, Harry E. Lerch, Anne L. Bates, M.D. Corum, Peter D. Warwick, Arthur C. Clark
2010, Organic Geochemistry (41) 997-1000
Organic intermediates in coal fluids produced by anaerobic biodegradation of geopolymers in coal play a key role in the production of methane in natural gas reservoirs. Laboratory biodegradation experiments on sub-bituminous coal from Texas, USA, were conducted using bioreactors to examine the organic intermediates relevant to methane production. Production of...
Analysis of solvent dyes in refined petroleum products by electrospray ionization mass spectrometry
Colleen E. Rostad
2010, Fuel (89) 997-1005
Solvent dyes are used to color refined petroleum products to enable differentiation between gasoline, diesel, and jet fuels. Analysis for these dyes in the hydrocarbon product is difficult due to their very low concentrations in such a complex matrix. Flow injection analysis/electrospray ionization/mass spectrometry in both negative and positive mode...
A new capture fraction method to map how pumpage affects surface water flow
S. A. Leake, H. W. Reeves, J.E. Dickinson
2010, Ground Water (48) 690-700
All groundwater pumped is balanced by removal of water somewhere, initially from storage in the aquifer and later from capture in the form of increase in recharge and decrease in discharge. Capture that results in a loss of water in streams, rivers, and wetlands now is a concern in many...
Assessment of multiple sources of anthropogenic and natural chemical inputs to a morphologically complex basin, Lake Mead, USA
Michael R. Rosen, P. C. Van Metre
2010, Palaeogeography, Palaeoclimatology, Palaeoecology (294) 30-43
Lakes with complex morphologies and with different geologic and land-use characteristics in their sub-watersheds could have large differences in natural and anthropogenic chemical inputs to sub-basins in the lake. Lake Mead in southern Nevada and northern Arizona, USA, is one such lake. To assess variations in chemical histories from 1935...
Response of a macrotidal estuary to changes in anthropogenic mercury loading between 1850 and 2000
E.M. Sunderl, J. Dalziel, A. Heyes, B.A. Branfireun, David P. Krabbenhoft, F.A.P.C. Gobas
2010, Environmental Science & Technology (44) 1698-1704
Methylmercury (MeHg) bioaccumulation in marine food webs poses risks to fish-consuming populations and wildlife. Here we develop and test an estuarine mercury cycling model for a coastal embayment of the Bay of Fundy, Canada. Mass budget calculations reveal that MeHg fluxes into sediments from settling solids exceed losses from sediment-to-water...
Transient electromagnetic mapping of clay units in the San Luis Valley, Colorado
David V. Fitterman, V. J. S. Grauch
2010, Conference Paper, Symposium on the Application of Geophysics to Engineering and Environmental Problems 2010
Transient electromagnetic soundings were used to obtain information needed to refine hydrologic models of the San Luis Valley, Colorado. The soundings were able to map an aquitard called the blue clay that separates an unconfined surface aquifer from a deeper confined aquifer. The blue clay forms a conductor with an average...
Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the midwestern united states
Jennifer L. Graham, Keith A. Loftin, Michael T. Meyer, Andrew C. Ziegler
2010, Environmental Science & Technology (44) 7361-7368
The mixtures of toxins and taste-and-odor compounds present during cyanobacterial blooms are not well characterized and of particular concern when evaluating potential human health risks. Cyanobacterial blooms were sampled in twenty-three Midwestern United States lakes and analyzed for community composition, thirteen cyanotoxins by liquid chromatography/mass spectrometry and immunoassay, and two...
Inter-comparison of hydro-climatic regimes across northern catchments: Synchronicity, resistance and resilience
S.K. Carey, D. Tetzlaff, J. Seibert, C. Soulsby, J. Buttle, H. Laudon, J. McDonnell, K. McGuire, D. Caissie, J. Shanley, M. Kennedy, K. Devito, J.W. Pomeroy
2010, Hydrological Processes (24) 3591-3602
The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern...
The annual cycles of phytoplankton biomass
Monika Winder, James E. Cloern
2010, Philosophical Transactions of the Royal Society B: Biological Sciences (365) 3215-3226
Terrestrial plants are powerful climate sentinels because their annual cycles of growth, reproduction and senescence are finely tuned to the annual climate cycle having a period of one year. Consistency in the seasonal phasing of terrestrial plant activity provides a relatively low-noise background from which phenological shifts can be detected...
Spatial distribution of pingos in Northern Asia
G. Grosse, Benjamin M. Jones
2010, Cryosphere Discussions (4) 1781-1837
Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of more than 6000 pingo locations in a 3.5 ?? 106 km2 region of...
Impact of biological soil crusts and desert plants on soil microfaunal community composition
B.J. Darby, D.A. Neher, J. Belnap
2010, Plant and Soil (328) 421-431
Carbon and nitrogen are supplied by a variety of sources in the desert food web; both vascular and non-vascular plants and cyanobacteria supply carbon, and cyanobacteria and plant-associated rhizosphere bacteria are sources of biological nitrogen fixation. The objective of this study was to compare the relative influence of vascular plants...
Theory, methods and tools for determining environmental flows for riparian vegetation: Riparian vegetation-flow response guilds
D.M. Merritt, M. L. Scott, Poff N. Leroy, G.T. Auble, D.A. Lytle
2010, Freshwater Biology (55) 206-225
Riparian vegetation composition, structure and abundance are governed to a large degree by river flow regime and flow-mediated fluvial processes. Streamflow regime exerts selective pressures on riparian vegetation, resulting in adaptations (trait syndromes) to specific flow attributes. Widespread modification of flow regimes by humans has resulted in extensive alteration of...
A rain splash transport equation assimilating field and laboratory measurements
T. Dunne, D.V. Malmon, S.M. Mudd
2010, Journal of Geophysical Research F: Earth Surface (115)
Process-based models of hillslope evolution require transport equations relating sediment flux to its major controls. An equation for rain splash transport in the absence of overland flow was constructed by modifying an approach developed by Reeve (1982) and parameterizing it with measurements from single-drop laboratory experiments and simulated rainfall on...
Influence of organic carbon loading, sediment associated metal oxide content and sediment grain size distributions upon Cryptosporidium parvum removal during riverbank filtration operations, Sonoma County, CA
D.W. Metge, R.W. Harvey, G. R. Aiken, R. Anders, G. Lincoln, James Jasperse
2010, Water Research (44) 1126-1137
This study assessed the efficacy for removing Cryptosporidium parvum oocysts of poorly sorted, Fe- and Al-rich, subsurface sediments collected from 0.9 to 4.9 and 1.7–13.9 m below land surface at an operating riverbank filtration (RBF) site (Russian River, Sonoma County, CA). Both formaldehyde-killed oocysts and oocyst-sized (3 μm) microspheres were employed in sediment-packed flow-through...
Mercury dynamics in relation to dissolved organic carbon concentration and quality during high flow events in three northeastern U.S. streams
Jason A. Dittman, James B. Shanley, Charles T. Driscoll, George R. Aiken, Ann T. Chalmers, Janet E. Towse, Pranesh Selvendiran
2010, Water Resources Research (46)
Mercury (Hg) contamination is widespread in remote areas of the northeastern United States. Forested uplands have accumulated a large reservoir of Hg in soil from decades of elevated anthropogenic deposition that can be released episodically to stream water during high flows. The objective of this study was to evaluate spatial...
Comparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings
Robert G. M. Spencer, George R. Aiken, Rachael Y. Dyda, Kenna D. Butler, Brian A. Bergamaschi, Peter J. Hernes
2010, Organic Geochemistry (41) 445-453
This manuscript highlights numerous incremental improvements in dissolved lignin measurements over the nearly three decades since CuO oxidation of lignin phenols was first adapted for environmental samples. Intercomparison of the recovery efficiency of three common lignin phenol concentration and isolation techniques, namely XAD, C18with both CH3OH (C18M) and CH3CN (C18A)...
Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise
T.W. Doyle, K. W. Krauss, W.H. Conner, A.S. From
2010, Forest Ecology and Management (259) 770-777
Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest...
A quarter century of declining suspended sediment fluxes in the Mississippi River and the effect of the 1993 flood
A. J. Horowitz
2010, Hydrological Processes (24) 13-34
Annual fluxes, flow-weighted concentrations and linear least squares trendline calculations for a number of long-term Mississippi River Basin (MRB) sampling sites covering 1981 through 2007, whilst somewhat 'noisy', display long-term patterns of decline. Annual flow-weighted concentration plots display the same long-term patterns of decline, but are less noisy because they...
Polycyclic aromatic hydrocarbons in soil of the Canadian River floodplain in Oklahoma
F. Sartori, T.L. Wade, J.L. Sericano, B.P. Mohanty, Karen A. Smith
2010, Journal of Environmental Quality (39) 568-579
The accumulation of polycyclic aromatic hydrocarbons (PAH) in soil, plants, and water may impart negative effects on ecosystem and human health. We quantified the concentration and distribution of 41 PAH (n = 32), organic C, total N, and S (n = 140) and investigated PAH sources using a chronosequence of...
A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO2 detection techniques and transport models
L.H. Spangler, L.M. Dobeck, K.S. Repasky, A.R. Nehrir, S.D. Humphries, C.J. Keith, J.A. Shaw, J.H. Rouse, A.B. Cunningham, S.M. Benson, C.M. Oldenburg, J.L. Lewicki, A.W. Wells, J.R. Diehl, B.R. Strazisar, J.E. Fessenden, T.A. Rahn, J.E. Amonette, J.L. Barr, W.L. Pickles, J.D. Jacobson, E. A. Silver, E.J. Male, H.W. Rauch, K.S. Gullickson, R. Trautz, Yousif K. Kharaka, J. Birkholzer, L. Wielopolski
2010, Environmental Earth Sciences (60) 227-239
A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO2 transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO2 release rates were chosen to be relevant to developing monitoring strategies for...
Source water controls on the character and origin of dissolved organic matter in streams of the Yukon River basin, Alaska
Jonathan A. O’Donnell, George R. Aiken, Evan S. Kane, Jeremy B. Jones
2010, Journal of Geophysical Research G: Biogeosciences (115) 1-12
Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate...
