A simulation/optimization model for groundwater resources management in the Afram Plains area, Ghana
S.M. Yidana
2008, Journal of Environmental Hydrology (16) 1-14
A groundwater flow simulation model was developed using available hydrogeo logical data to A groundwater flow simulation model was developed using available hydrogeological data to describe groundwater flow in the Afram Plains area. A nonlinear optimization model was then developed and solved for the management of groundwater resources to meet...
Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms
N. Watanabe, T.H. Harter, B.A. Bergamaschi
2008, Conference Paper, Journal of Environmental Quality
Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the...
Decadal-scale changes of pesticides in ground water of the United States, 1993-2003
L. M. Bexfield
2008, Conference Paper, Journal of Environmental Quality
Pesticide data for ground water sampled across the United States between 1993-1995 and 2001-2003 by the U.S. Geological Survey National Water-Quality Assessment Program were evaluated for trends in detection frequency and concentration. The data analysis evaluated samples collected from a total of 362 wells located in 12 local well networks...
Temporal trends in nitrate and selected pesticides in mid-atlantic ground water
L.M. Debrewer, S.W. Ator, J. M. Denver
2008, Conference Paper, Journal of Environmental Quality
Evaluating long-term temporal trends in regional ground-water quality is complicated by variable hydrogeologic conditions and typically slow flow, and such trends have rarely been directly measured. Ground-water samples were collected over near-decadal and annual intervals from unconfined aquifers in agricultural areas of the Mid-Atlantic region, including fractured carbonate rocks in...
Decadal-scale changes of nitrate in ground water of the United States, 1988-2004
Michael G. Rupert
2008, Journal of Environmental Quality (37) S240-S248
This study evaluated decadal-scale changes of nitrate concentrations in groundwater samples collected by the USGS National Water-Quality Assessment Program from 495 wells in 24 well networks across the USA in predominantly agricultural areas. Each well network was sampled once during 1988-1995 and resampled once during 2000-2004. Statistical tests of decadal-scale...
Wildfire effects on water temperature and selection of breeding sites by the Boreal Toad (Bufo boreas) in seasonal wetlands
B. R. Hossack, P.S. Corn
2008, Herpetological Conservation and Biology (3) 46-54
Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature,...
Near-decadal changes in nitrate and pesticide concentrations in the South Platte River alluvial aquifer, 1993-2004
S.S. Paschke, K.R. Schaffrath, S.L. Mashbum
2008, Journal of Environmental Quality (37) S281-S295
The lower South Platte River basin of Colorado and Nebraska is an area of intense agriculture supported by surface-water diversions from the river and ground-water pumping from a valley-fill alluvial aquifer. Two well networks consisting of 45 wells installed in the South Platte alluvial aquifer were sampled in the early...
Increasing shallow groundwater CO2 and limestone weathering, Konza Prairie, USA
G.L. Macpherson, J.A. Roberts, J.M. Blair, M.A. Townsend, D.A. Fowle, K. R. Beisner
2008, Geochimica et Cosmochimica Acta (72) 5581-5599
In a mid-continental North American grassland, solute concentrations in shallow, limestone-hosted groundwater and adjacent surface water cycle annually and have increased steadily over the 15-year study period, 1991-2005, inclusive. Modeled groundwater CO2, verified by measurements of recent samples, increased from 10-2.05 atm to 10-1.94 atm, about a 20% increase, from...
The Lower Triassic Sorkh Shale Formation of the Tabas Block, east central Iran: Succesion of a failed-rift basin at the Paleotethys margin
Y. Lasemi, M. Ghomashi, H. Amin-Rasouli, A. Kheradmand
2008, Carbonates and Evaporites (23) 21-38
The Lower Triassic Sorkh Shale Formation is a dominantly red colored marginal marine succession deposited in the north-south trending Tabas Basin of east central Iran. It is correlated with the unconformity-bounded lower limestone member of the Elika Formation of the Alborz Mountains of northern Iran. The Sorkh Shale is bounded...
Habitat features affect bluehead sucker, flannelmouth sucker, and roundtail chub across a headwater tributary system in the Colorado River Basin
M.R. Bower, W.A. Hubert, F.J. Rahel
2008, Journal of Freshwater Ecology (23) 347-357
We assessed the distributions of three species of conservation concern, bluehead sucker (Catostomus discobolus), flannelmouth sucker (Catostomus latipinnis), and roundtail chub (Gila robusta), relative to habitat features across a headwater tributary system of the Colorado River basin in Wyoming. We studied the upper Muddy Creek watershed, Carbon County, portions of...
Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts
M. A. Bowker, J. Belnap, Bala V. Chaudhary, N.C. Johnson
2008, Soil Biology and Biochemistry (40) 2309-2316
Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which...
Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005
M.S. Dalton, E. A. Frick
2008, Conference Paper, Journal of Environmental Quality
Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological...
Introduction to the U.S. Geological Survey National Water-Quality Assessment (NAWQA) of ground-water quality trends and comparison to other national programs
Michael R. Rosen, W.W. Lapham
2008, Conference Paper, Journal of Environmental Quality
Assessment of temporal trends in national ground-water quality networks are rarely published in scientific journals. This is partly due to the fact that long-term data from these types of networks are uncommon and because many national monitoring networks are not driven by hypotheses that can be easily incorporated into scientific...
Agriculture-related trends in groundwater quality of the glacial deposits aquifer, central Wisconsin
D. A. Saad
2008, Conference Paper, Journal of Environmental Quality
Measuring and understanding trends in groundwater quality is necessary for determining whether changes in land-management practices have an effect on groundwater quality. This paper describes an approach that was used to measure and understand trends using data from two groundwater studies conducted in central Wisconsin as part of the USGS...
Development of pan-Arctic database for river chemistry
J.W. McClelland, R.M. Holmes, B. J. Peterson, R. Amon, T. Brabets, L. Cooper, J. Gibson, V.V. Gordeev, C. Guay, D. Milburn, R. Staples, P.A. Raymond, I. Shiklomanov, Robert G. Striegl, A. Zhulidov, T. Gurtovaya, S. Zimov
2008, Eos, Transactions, American Geophysical Union (89) 217-218
More than 10% of all continental runoff flows into the Arctic Ocean. This runoff is a dominant feature of the Arctic Ocean with respect to water column structure and circulation. Yet understanding of the chemical characteristics of runoff from the pan-Arctic watershed is surprisingly limited. The Pan- Arctic River Transport...
Using open hole and cased-hole resistivity logs to monitor gas hydrate dissociation during a thermal test in the mallik 5L-38 research well, Mackenzie Delta, Canada
B.I. Anderson, T. S. Collett, R.E. Lewis, I. Dubourg
2008, Conference Paper, Petrophysics
Gas hydrates, which are naturally occurring ice-like combinations of gas and water, have the potential to provide vast amounts of natural gas from the world's oceans and polar regions. However, producing gas economically from hydrates entails major technical challenges. Proposed recovery methods such as dissociating or melting gas hydrates by...
Detecting biological responses to flow management: Missed opportunities; future directions
Y. Souchon, C. Sabaton, R. Deibel, D. Reiser, J. Kershner, M. Gard, C. Katopodis, P. Leonard, N.L. Poff, W.J. Miller, B. L. Lamb
2008, Conference Paper, River Research and Applications
The conclusions of numerous stream restoration assessments all around the world are extremely clear and convergent: there has been insufficient appropriate monitoring to improve general knowledge and expertise. In the specialized field of instream flow alterations, we consider that there are several opportunities comparable to full-size experiments. Hundreds of water...
Estimation of walrus populations on sea ice with infrared imagery and aerial photography
Mark S. Udevitz, D. M. Burn, M.A. Webber
2008, Marine Mammal Science (24) 57-70
Population sizes of ice-associated pinnipeds have often been estimated with visual or photographic aerial surveys, but these methods require relatively slow speeds and low altitudes, limiting the area they can cover. Recent developments in infrared imagery and its integration with digital photography could allow substantially larger areas to be surveyed...
Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA
Judith Z. Drexler, Frank E. Anderson, Richard L. Snyder
2008, Hydrological Processes (22) 725-735
The surface renewal method was used to estimate evapotranspiration (ET) for a restored marsh on Twitchell Island in the Sacramento–San Joaquin Delta, California, USA. ET estimates for the marsh, together with reference ET measurements from a nearby climate station, were used to determine crop coefficients over a 3‐year period during...
A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques
S.J. Nelson, K.B. Johnson, K.C. Weathers, C.S. Loftin, I.J. Fernandez, J. S. Kahl, D. P. Krabbenhoft
2008, Applied Geochemistry (23) 384-398
Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack...
Arsenic transformation and mobilization from minerals by the arsenite oxidizing strain WAO
E.D. Rhine, K.M. Onesios, M.E. Serfes, J.R. Reinfelder, L.Y. Young
2008, Environmental Science & Technology (42) 1423-1429
Analysis of arsenic concentrations in New Jersey well water from the Newark Basin showed up to 15% of the wells exceed 10 ??g L-1, with a maximum of 215 ??g L-1. In some geologic settings in the basin, this mobile arsenic could be from the weathering of pyrite (FeS2) found...
Environmental tracers as indicators of karst conduits in groundwater in South Dakota, USA
Andrew J. Long, J.F. Sawyer, L.D. Putnam
2008, Hydrogeology Journal (16) 263-280
Environmental tracers sampled from the carbonate Madison aquifer on the eastern flank of the Black Hills, South Dakota, USA indicated the approximate locations of four major karst conduits. Contamination issues are a major concern because these conduits are characterized by direct connections to sinking streams, high groundwater velocities, and proximity...
Mercury sedimentation in lakes in western Whatcom County, Washington, USA and its relation to local industrial and municipal atmospheric sources
A.J. Paulson, D. Norton
2008, Water, Air, & Soil Pollution (189) 5-19
Concentrations of mercury (Hg) were measured in six dated cores from four lakes in western Whatcom County, Washington, USA, that were at various bearings from a chlor-alkali plant, two municipal waste incinerators and a municipal sewage sludge incinerator. The importance of atmospheric emissions of Hg from these local municipal and...
A 1000-year sediment record of recurring hypoxia off the Mississippi River: The potential role of terrestrially-derived organic matter inputs
P.W. Swarzenski, P.L. Campbell, L.E. Osterman, R.Z. Poore
2008, Marine Chemistry (109) 130-142
A suite of inorganic and organic geochemical tracers and a low-oxygen tolerant benthic faunal index ('PEB') were measured in a 14C-dated 2+??m long gravity core collected on the Louisiana shelf adjacent to the Mississippi River delta to study potential millennium-scale low-oxygen events. Periodic down-core excursions in the PEB index throughout...
Population structure and genetic diversity of black redhorse (Moxostoma duquesnei) in a highly fragmented watershed
S.M. Reid, C.C. Wilson, N.E. Mandrak, L.M. Carl
2008, Conservation Genetics (9) 531-546
Dams have the potential to affect population size and connectivity, reduce genetic diversity, and increase genetic differences among isolated riverine fish populations. Previous research has reported adverse effects on the distribution and demographics of black redhorse (Moxostoma duquesnei), a threatened fish species in Canada. However, effects on genetic diversity and...
