Effects of the antimicrobial sulfamethoxazole on groundwater bacterial enrichment
Jennifer C. Underwood, Ronald W. Harvey, David W. Metge, Deborah A. Repert, Laura K. Baumgartner, Richard L. Smith, Timberly M. Roane, Larry B. Barber
2011, Environmental Science & Technology (45) 3096-3101
The effects of “trace” (environmentally relevant) concentrations of the antimicrobial agent sulfamethoxazole (SMX) on the growth, nitrate reduction activity, and bacterial composition of an enrichment culture prepared with groundwater from a pristine zone of a sandy drinking-water aquifer on Cape Cod, MA, were assessed by laboratory incubations. When the enrichments...
On the hydrologic adjustment of climate-model projections: The potential pitfall of potential evapotranspiration
P. C. D. Milly, K.A. Dunne
2011, Earth Interactions (15) 1-14
Hydrologic models often are applied to adjust projections of hydroclimatic change that come from climate models. Such adjustment includes climate-bias correction, spatial refinement ("downscaling"), and consideration of the roles of hydrologic processes that were neglected in the climate model. Described herein is a quantitative analysis of the effects of hydrologic...
Biogeochemical processes on tree islands in the greater everglades: Initiating a new paradigm
P.R. Wetzel, Fred H. Sklar, C.A. Coronado, T.G. Troxler, S.L. Krupa, P.L. Sullivan, S. Ewe, R.M. Price, S. Newman, William H. Orem
2011, Critical Reviews in Environmental Science and Technology (41) 670-701
Scientists’ understanding of the role of tree islands in the Everglades has evolved from a plant community of minor biogeochemical importance to a plant community recognized as the driving force for localized phosphorus accumulation within the landscape. Results from this review suggest that tree transpiration, nutrient infiltration from the soil...
Water storage at the Panola Mountain Research Watershed, Georgia, USA
N.E. Peters, Brent T. Aulenbach
2011, Hydrological Processes (25) 3878-3889
Storage is a major component of a catchment water balance particularly when the water balance components are evaluated on short time scales, that is, less than annual. We propose a method of determining the storage-discharge relation using an exponential function and daily precipitation, potential evapotranspiration (PET) and baseflow during the...
Assessing the detail needed to capture rainfall-runoff dynamics with physics-based hydrologic response simulation
B.B. Mirus, B.A. Ebel, C.S. Heppner, K. Loague
2011, Water Resources Research (47)
Concept development simulation with distributed, physics-based models provides a quantitative approach for investigating runoff generation processes across environmental conditions. Disparities within data sets employed to design and parameterize boundary value problems used in heuristic simulation inevitably introduce various levels of bias. The objective was to evaluate the impact of boundary...
Simulating the potential effects of climate change in two Colorado basins and at two Colorado ski areas
William Battaglin, Lauren E. Hay, Steve Markstrom
2011, Earth Interactions (15) 1-23
The mountainous areas of Colorado are used for tourism and recreation, and they provide water storage and supply for municipalities, industries, and agriculture. Recent studies suggest that water supply and tourist industries such as skiing are at risk from climate change. In this study, a distributed-parameter watershed model, the Precipitation-Runoff...
New insights from well responses to fluctuations in barometric pressure
J.J. Butler, W. Jin, G.A. Mohammed, E.C. Reboulet
2011, Ground Water (49) 525-533
Hydrologists have long recognized that changes in barometric pressure can produce changes in water levels in wells. The barometric response function (BRF) has proven to be an effective means to characterize this relationship; we show here how it can also be utilized to glean valuable insights into semi-confined aquifer systems....
Nest success of snowy plovers (Charadrius nivosus) in the Southern high plains of Texas
S.T. Saalfeld, Warren C. Conway, D.A. Haukos, W.P. Johnson
2011, Waterbirds (34) 389-399
Snowy Plovers (Charadrius nivosus) nesting on edges of saline lakes within the Southern High Plains (SHP) of Texas are threatened by habitat degradation due to reduced artesian spring flow, making many saline lakes unsuitable for nesting and migrating shorebirds. Factors influencing nest success were evaluated, current nest success estimates in...
Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA
D.R. Hirmas, R.C. Graham, K.J. Kendrick
2011, Catena (87) 408-420
Mountains comprise an extensive and visually prominent portion of the landscape in the Mojave Desert, California. Landform surface properties influence the role these mountains have in geomorphic processes such as dust flux and surface hydrology across the region. The primary goal of this study was to describe and quantify land...
Hydrologic response of catchments to precipitation: Quantification of mechanical carriers and origins of water
Y.-J. Park, E.A. Sudicky, A.E. Brookfield, J.P. Jones
2011, Water Resources Research (47)
Precipitation-induced overland and groundwater flow and mixing processes are quantified to analyze the temporal (event and pre-event water) and spatial (groundwater discharge and overland runoff) origins of water entering a stream. Using a distributed-parameter control volume finite-element simulator that can simultaneously solve the fully coupled partial differential equations describing 2-D...
The importance of warm season warming to western U.S. streamflow changes
T. Das, D.W. Pierce, D.R. Cayan, J.A. Vano, D.P. Lettenmaier
2011, Geophysical Research Letters (38)
Warm season climate warming will be a key driver of annual streamflow changes in four major river basins of the western U.S., as shown by hydrological model simulations using fixed precipitation and idealized seasonal temperature changes based on climate projections with SRES A2 forcing. Warm season (April-September) warming reduces streamflow...
Diurnal trends in methylmercury concentration in a wetland adjacent to Great Salt Lake, Utah, USA
D. L. Naftz, J.R. Cederberg, D. P. Krabbenhoft, K. R. Beisner, J. Whitehead, J. Gardberg
2011, Chemical Geology (283) 78-86
A 24-h field experiment was conducted during July 2008 at a wetland on the eastern shore of Great Salt Lake (GSL) to assess the diurnal cycling of methylmercury (MeHg). Dissolved (< 0.45 μm) MeHg showed a strong diurnal variation with consistently decreasing concentrations during daylight periods and...
Millennial precipitation reconstruction for the Jemez Mountains, New Mexico, reveals changing drought signal
Ramzi Touchan, Connie A. Woodhouse, David M. Meko, Craig D. Allen
2011, International Journal of Climatology (31) 896-906
Drought is a recurring phenomenon in the American Southwest. Since the frequency and severity of hydrologic droughts and other hydroclimatic events are of critical importance to the ecology and rapidly growing human population of this region, knowledge of long-term natural hydroclimatic variability is valuable for resource managers and policy-makers. An...
Lake carbonate-δ18 records from the Yukon Territory, Canada: Little Ice Age moisture variability and patterns
Lesleigh Anderson, Bruce P. Finney, Mark D. Shapley
2011, Quaternary Science Reviews (30) 887-898
A 1000-yr history of climate change in the central Yukon Territory, Canada, is inferred from sediment composition and isotope geochemistry from small, groundwater fed, Seven Mile Lake. Recent observations of lake-water δ18O, lake level, river discharge, and climate variations, suggest that changes in regional effective moisture (precipitation minus evaporation) are...
Calibration of models using groundwater age
Ward E. Sanford
2011, Hydrogeology Journal (19) 13-16
There have been substantial efforts recently by geochemists to determine the age of groundwater (time since water entered the system) and its uncertainty, and by hydrologists to use these data to help calibrate groundwater models. This essay discusses the calibration of models using groundwater age, with conclusions that emphasize what...
Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers
A.J. Lind, P.Q. Spinks, G. M. Fellers, H.B. Shaffer
2011, Conservation Genetics (12) 269-284
Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b and ND2 fragments...
The challenge of interpreting environmental tracer concentrations in fractured rock and carbonate aquifers
Allen M. Shapiro
2011, Hydrogeology Journal (19) 9-12
No abstract available....
Remote sensing of soil moisture using airborne hyperspectral data
M. Finn, M. Lewis, D. Bosch, Mario Giraldo, K. Yamamoto, D. Sullivan, R. Kincaid, R. Luna, G. Allam, Craig Kvien, Murray Williams
2011, GIScience and Remote Sensing (48) 522-540
Landscape assessment of soil moisture is critical to understanding the hydrological cycle at the regional scale and in broad-scale studies of biophysical processes affected by global climate changes in temperature and precipitation. Traditional efforts to measure soil moisture have been principally restricted to in situ measurements, so remote sensing techniques...
Mars: the evolutionary history of the northern lowlands based on crater counting and geologic mapping
S.C. Werner, K. L. Tanaka, J.A. Skinner Jr.
2011, Planetary and Space Science (59) 1143-1165
The geologic history of planetary surfaces is most effectively determined by joining geologic mapping and crater counting which provides an iterative, qualitative and quantitative method for defining relative ages and absolute model ages. Based on this approach, we present spatial and temporal details regarding the evolution of the Martian northern...
Mercury distribution and lipid oxidation in fish muscle: Effects of washing and isoelectric protein precipitation
Y. Gong, David P. Krabbenhoft, L. Ren, B. Egelandsdal, M.P. Richards
2011, Journal of Agricultural and Food Chemistry (59) 11050-11057
Nearly all the mercury (Hg) in whole muscle from whitefish (Coregonus clupeaformis) and walleye (Sander vitreus) was present as methyl mercury (MeHg). The Hg content in whole muscle from whitefish and walleye was 0.04–0.09 and 0.14–0.81 ppm, respectively. The myofibril fraction contained...
Fluoride geochemistry of thermal waters in Yellowstone National Park: I. Aqueous fluoride speciation
Y. Deng, D. Kirk Nordstrom, R. Blaine McCleskey
2011, Geochimica et Cosmochimica Acta (75) 4476-4489
Thermal water samples from Yellowstone National Park (YNP) have a wide range of pH (1–10), temperature, and high concentrations of fluoride (up to 50 mg/l). High fluoride concentrations are found in waters with field pH higher than 6 (except those in Crater Hills) and temperatures higher than 50 °C based on data...
Investigating the spatial distribution of water levels in the Mackenzie Delta using airborne LiDAR
C. Hopkinson, N. Crasto, P. Marsh, D. Forbes, L. Lesack
2011, Hydrological Processes (25) 2995-3011
Airborne light detection and ranging (LiDAR) data were used to map water level (WL) and hydraulic gradients (δH/δx) in the Mackenzie Delta. The LiDAR WL data were validated against eight independent hydrometric gauge measurements and demonstrated mean offsets from − 0·22 to + 0·04 m (σ< 0·11). LiDAR‐based WL gradients...
Hillslope chemical weathering across Paraná, Brazil: a data mining-GIS hybrid approach
Fabio Iwashita, Michael J. Friedel, Carlos Roberto de Souza Filho, Stephen J. Fraser
2011, Geomorphology (132) 167-175
Self-organizing map (SOM) and geographic information system (GIS) models were used to investigate the nonlinear relationships associated with geochemical weathering processes at local (~100 km2) and regional (~50,000 km2) scales. The data set consisted of 1) 22 B-horizon soil variables: P, C, pH, Al, total acidity, Ca, Mg, K, total cation exchange...
The influence of irrigation water on the hydrology and lake water budgets of two small arid-climate lakes in Khorezm, Uzbekistan
J. Scott, Michael R. Rosen, L. Saito, D.L. Decker
2011, Journal of Hydrology (410) 114-125
Little is known regarding the origins and hydrology of hundreds of small lakes located in the western Uzbekistan province of Khorezm, Central Asia. Situated in the Aral Sea Basin, Khorezm is a productive agricultural region, growing mainly cotton, wheat, and rice. Irrigation is provided by an extensive canal network that...
A computer program for flow-log analysis of single holes (FLASH)
F. D. Day-Lewis, C. D. Johnson, Frederick L. Paillet, K. J. Halford
2011, Ground Water (49) 926-931
A new computer program, FLASH (Flow-Log Analysis of Single Holes), is presented for the analysis of borehole vertical flow logs. The code is based on an analytical solution for steady-state multilayer radial flow to a borehole. The code includes options for (1) discrete fractures and (2) multilayer aquifers. Given vertical...
