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Page 696, results 17376 - 17400

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Multi-gauge Calibration for modeling the Semi-Arid Santa Cruz Watershed in Arizona-Mexico Border Area Using SWAT
Rewati Niraula, Laura A. Norman, Thomas Meixner, James B. Callegary
2012, Air, Soil and Water Research (2012) 41-57
In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the...
Community-level response of fishes and aquatic macroinvertebrates to stream restoration in a third-order tributary of the Potomac River, USA
S.M. Selego, C.L. Rose, G.T. Merovich Jr., Stuart A. Welsh, James T. Anderson
2012, International Journal of Ecology (2012)
Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two...
The influence of wave energy and sediment transport on seagrass distribution
Andrew W. Stevens, Jessica R. Lacy
2012, Estuaries and Coasts (35) 92-108
A coupled hydrodynamic and sediment transport model (Delft3D) was used to simulate the water levels, waves, and currents associated with a seagrass (Zostera marina) landscape along a 4-km stretch of coast in Puget Sound, WA, USA. A hydroacoustic survey of seagrass percent cover and nearshore bathymetry was conducted, and...
Climate change and human health: Spatial modeling of water availability, malnutrition, and livelihoods in Mali, Africa
Marta M. Jankowska, David Lopez-Carr, Chris Funk, Gregory J. Husak, Z.A. Chafe
2012, Applied Geography (33) 4-15
This study develops a novel approach for projecting climate trends in the Sahel in relation to shifting livelihood zones and health outcomes. Focusing on Mali, we explore baseline relationships between temperature, precipitation, livelihood, and malnutrition in 407 Demographic and Health Survey (DHS) clusters with a total of 14,238 children, resulting...
The paleohydrology of unsaturated and saturated zones at Yucca Mountain, Nevada, and vicinity
James B. Paces, Joseph F. Whelan
John S. Stuckless, editor(s)
2012, Book chapter, Hydrology and geochemistry of Yucca Mountain and vicinity, Southern Nevada and California
Surface, unsaturated-zone, and saturated-zone hydrologic conditions at Yucca Mountain responded to past climate variations and are at least partly preserved by sediment, fossil, and mineral records. Characterizing past hydrologic conditions in surface and subsurface environments helps to constrain hydrologic responses expected under future climate conditions and improve predictions of repository...
Power analysis and trend detection for water quality monitoring data. An application for the Greater Yellowstone Inventory and Monitoring Network
Kathryn M. Irvine, Kezia Manlove, Cynthia Hollimon
2012, Natural Resource Report NPS/GRYN/NRR-2012/556
An important consideration for long term monitoring programs is determining the required sampling effort to detect trends in specific ecological indicators of interest. To enhance the Greater Yellowstone Inventory and Monitoring Network’s water resources protocol(s) (O’Ney 2006 and O’Ney et al. 2009 [under review]), we developed a set of tools...
Thermal infrared remote sensing of water temperature in riverine landscapes
Rebecca N. Handcock, Christian E. Torgersen, Keith A. Cherkauer, Alan R. Gillespie, Tockner Klement, Russell N. Faux, Jing Tan
Patrice E. Carbonneau, Hervé Piégay, editor(s)
2012, Book chapter, Fluvial remote sensing for science and management
Water temperature in riverine landscapes is an important regional indicator of water quality that is influenced by both ground- and surface-water inputs, and indirectly by land use in the surrounding watershed (Brown and Krygier, 1970; Beschta et al., 1987; Chen et al., 1998; Poole and Berman, 2001).Coldwater fishes such as...
Nekton density patterns and hurricane recovery in submerged aquatic vegetation, and along non-vegetated natural and created edge habitats
Megan La Peyre, J. Gordon
2012, Estuarine, Coastal and Shelf Science (98) 108-118
We compared nekton habitat value of submerged aquatic vegetation, flooded non-vegetated natural and man-made edge habitats in mesohaline interior marsh areas in southwest Louisiana using a 1-m2 throw trap and 3-mm bag seine. When present, SAV habitats supported close to 4 times greater densities and higher species richness of nekton as compared to either natural or man-made...
Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins
Richard H. Coupe, Stephen J. Kalkhoff, Paul D. Capel, Caroline Gregoire
2012, Pest Management Science (68) 16-30
BACKGROUND: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10...
Evaluation of MODFLOW-LGR in connection with a synthetic regional-scale model
T.N. Vilhelmsen, S. Christensen, Steffen W. Mehl
2012, Ground Water (50) 118-132
This work studies costs and benefits of utilizing local‐grid refinement (LGR) as implemented in MODFLOW‐LGR to simulate groundwater flow in a buried tunnel valley interacting with a regional aquifer. Two alternative LGR methods were used: the shared‐node (SN) method and the ghost‐node (GN) method. To conserve flows the SN method...
Soil C and N patterns in a semiarid piñon-juniper woodland: Topography of slope and ephemeral channels add to canopy-intercanopy heterogeneity
Darin J. Law, David D. Breshears, Michael H. Ebinger, Clifton W. Meyer, Craig D. Allen
2012, Journal of Arid Environments (79) 20-24
Carbon and nitrogen are crucial to semiarid woodlands, determining decomposition, production and redistribution of water and nutrients. Carbon and nitrogen are often greater beneath canopies than intercanopies. Upslope vs. downslope position and ephemeral channels might also cause variation in C and N. Yet, few studies have simultaneously evaluated spatial variation...
Effects of suture material and ultrasonic transmitter size on survival, growth, wound healing, and tag expulsion in rainbow trout
Tomas J. Ivasauskas, Phillip William Bettoli, T. Holt
2012, Transactions of the American Fisheries Society (141) 100-106
We examined the effects of suture material (braided silk versus Monocryl) and relative ultrasonic transmitter size on healing, growth, mortality, and tag retention in rainbow trout Oncorhynchus mykiss. In experiment 1, 40 fish (205–281 mm total length [TL], 106–264 g) were implanted with Sonotronics IBT‐96–2 (23 × 7 mm; weight in...
Experimental determination of soil heat storage for the simulation of heat transport in a coastal wetland
Michael Swain, Matthew Swain, Melinda Lohmann, Eric Swain
2012, Journal of Hydrology (422-423) 53-62
Two physical experiments were developed to better define the thermal interaction of wetland water and the underlying soil layer. This information is important to numerical models of flow and heat transport that have been developed to support biological studies in the South Florida coastal wetland areas. The experimental apparatus...
Impacts of biofuels production alternatives on water quantity and quality in the Iowa River Basin
Y. Wu, S. Liu
2012, Biomass and Bioenergy (36) 182-191
Corn stover as well as perennial grasses like switchgrass (Panicum virgatum) and miscanthus are being considered as candidates for the second generation biofuel feedstocks. However, the challenges to biofuel development are its effects on the environment, especially water quality. This study evaluates the long-term impacts of biofuel production alternatives (e.g.,...
Generation and evolution of hydrothermal fluids at Yellowstone: Insights from the Heart Lake Geyser Basin
J. B. Lowenstern, D. Bergfeld, William C. Evans, S. Hurwitz
2012, Geochemistry, Geophysics, Geosystems (13)
We sampled fumaroles and hot springs from the Heart Lake Geyser Basin (HLGB), measured water and gas discharge, and estimated heat and mass flux from this geothermal area in 2009. The combined data set reveals that diverse fluids share an origin by mixing of deep solute-rich parent water with dilute...
Increased atmospheric deposition of mercury in reference lakes near major urban areas
P. C. Van Metre
2012, Environmental Pollution (162) 209-215
Atmospheric deposition of Hg is the predominant pathway for Hg to reach sensitive ecosystems, but the importance of emissions on near-field deposition remains unclear. To better understand spatial variability in Hg deposition, mercury concentrations were analyzed in sediment cores from 12 lakes with undeveloped watersheds near to (<50 km) and remote...
Laboratory investigations of the effects of nitrification-induced acidification on Cr cycling in vadose zone material partially derived from ultramafic rocks
Christopher T. Mills, Martin B. Goldhaber
2012, Science of the Total Environment (435-436) 363-373
Sacramento Valley (California, USA) soils and sediments have high concentrations of Cr(III) because they are partially derived from ultramafic material. Some Cr(III) is oxidized to more toxic and mobile Cr(VI) by soil Mn oxides. Valley soils typically have neutral to alkaline pH at which Cr(III) is highly immobile. Much of...
Comparison of electrical conductivity calculation methods for natural waters
R. Blaine McCleskey, D. Kirk Nordstrom, Joseph N. Ryan
2012, Limnology and Oceanography: Methods (10) 952-967
The capability of eleven methods to calculate the electrical conductivity of a wide range of natural waters from their chemical composition was investigated. A brief summary of each method is presented including equations to calculate the conductivities of individual ions, the ions incorporated, and the method's limitations. The ability of...
Hydrogen isotope investigation of amphibole and biotite phenocrysts in silicic magmas erupted at Lassen Volcanic Center, California
S.J. Underwood, T.C. Feeley, M.A. Clynne
2012, Journal of Volcanology and Geothermal Research (227-228) 32-49
Hydrogen isotope ratio, water content and Fe3 +/Fe2 + in coexisting amphibole and biotite phenocrysts in volcanic rocks can provide insight into shallow pre- and syn-eruptive magmatic processes such as vesiculation, and lava drainback with mixing into less devolatilized magma that erupts later in a volcanic sequence. We studied four...
Habitat and prey availability attributes associated with juvenile and early adult pallid sturgeon occurrence in the Missouri River, USA
Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly
2012, Endangered Species Research (16) 225-234
The pallid sturgeon Scaphirhynchus albus is a federally endangered species native to the Missouri and lower Mississippi Rivers, USA. As part of recovery efforts, over 360000 pallid sturgeon have been stocked into the Missouri River since 1994, and a standardized, long-term monitoring program was initiated in 2003. Understanding the distribution...
An application and extension of the constraints–effects–mitigation model to Minnesota waterfowl hunting
Susan A. Schroeder, David C. Fulton, Jeffrey S. Lawrence, Steven D. Cordts
2012, Human Dimensions of Wildlife (17) 174-192
This study extends modeling work on the leisure constraint negotiation process from physically active leisure and celebrity fandom to hunting. We test a model derived from the constraints–effects–mitigation model of leisure participation. The model is examined in the context of continued Minnesota waterfowl hunting among a sample of Minnesota residents...
Three-dimensional sensitivity distribution and sample volume of low-induction-number electromagnetic-induction instruments
James B. Callegary, T.P.A. Ferre, R.W. Groom
2012, Soil Science Society of America Journal (76) 85-91
There is an ongoing effort to improve the understanding of the correlation of soil properties with apparent soil electrical conductivity as measured by low‐induction‐number electromagnetic‐induction (LIN FEM) instruments. At a minimum, the dimensions of LIN FEM instruments' sample volume, the spatial distribution of sensitivity within that volume, and implications for...