Investigating the effects of point source and nonpoint source pollution on the water quality of the East River (Dongjiang) in South China
Yiping Wu, Ji Chen
2013, Ecological Indicators (32) 294-304
Understanding the physical processes of point source (PS) and nonpoint source (NPS) pollution is critical to evaluate river water quality and identify major pollutant sources in a watershed. In this study, we used the physically-based hydrological/water quality model, Soil and Water Assessment Tool, to investigate the influence of PS and...
Analyzing the water budget and hydrological characteristics and responses to land use in a monsoonal climate river basin in South China
Yiping Wu, Ji Chen
2013, Environmental Management (51) 1174-1186
Hydrological models have been increasingly used by hydrologists and water resource managers to understand natural processes and human activities that affect watersheds. In this study, we use the physically based model, Soil and Water Assessment Tool (SWAT), to investigate the hydrological processes in the East River Basin in South China,...
Simulations of groundwater flow, transport, and age in Albuquerque, New Mexico, for a study of transport of anthropogenic and natural contaminants (TANC) to public-supply wells
Charles E. Heywood
2013, Scientific Investigations Report 2012-5242
Vulnerability to contamination from manmade and natural sources can be characterized by the groundwater-age distribution measured in a supply well and the associated implications for the source depths of the withdrawn water. Coupled groundwater flow and transport models were developed to simulate the transport of the geochemical age-tracers carbon-14, tritium,...
Reconciling resource utilization and resource selection functions
Mevin Hooten, Ephraim M. Hanks, Devin S. Johnson, Mat W. Alldredge
2013, Journal of Animal Ecology (52) 1146-1154
Summary: 1. Analyses based on utilization distributions (UDs) have been ubiquitous in animal space use studies, largely because they are computationally straightforward and relatively easy to employ. Conventional applications of resource utilization functions (RUFs) suggest that estimates of UDs can be used as response variables in a regression involving spatial...
Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Herat mineral district in Afghanistan: Chapter T in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan
Philip A. Davis, Scott A. Arko, Michelle L. Harbin
2013, Data Series 709-T
The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the...
Microhabitat use of the diamond darter
Stuart A. Welsh, Dustin M. Smith, Nate D. Taylor
2013, Ecology of Freshwater Fish (22) 587-595
The only known extant population of the diamond darter (Crystallaria cincotta) exists in the lower 37 km of Elk River, WV, USA. Our understanding of diamond darter habitat use was previously limited, because few individuals have been observed during sampling with conventional gears. We quantified microhabitat use of diamond darters based...
Use of general purpose graphics processing units with MODFLOW
Joseph D. Hughes, Jeremy T. White
2013, Ground Water
To evaluate the use of general-purpose graphics processing units (GPGPUs) to improve the performance of MODFLOW, an unstructured preconditioned conjugate gradient (UPCG) solver has been developed. The UPCG solver uses a compressed sparse row storage scheme and includes Jacobi, zero fill-in incomplete, and modified-incomplete lower-upper (LU) factorization, and generalized least-squares...
Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon
Kurt D. Carpenter, Stewart A. Rounds
2013, Scientific Investigations Report 2013-5037
Phytoplankton populations in the Tualatin River in northwestern Oregon are an important component of the dissolved oxygen (DO) budget of the river and are critical for maintaining DO levels in summer. During the low-flow summer period, sufficient nutrients and a long residence time typically combine with ample sunshine and warm...
MODFLOW–USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation
Sorab Panday, Christian D. Langevin, Richard G. Niswonger, Motomu Ibaraki, Joseph D. Hughes
2013, Techniques and Methods 6-A45
A new version of MODFLOW, called MODFLOW–USG (for UnStructured Grid), was developed to support a wide variety of structured and unstructured grid types, including nested grids and grids based on prismatic triangles, rectangles, hexagons, and other cell shapes. Flexibility in grid design can be used to focus resolution along rivers...
Benthic substrate classification map: Gulf Islands National Seashore
Dawn Lavoie, James Flocks, Dave Twichell, Kate Rose
2013, Open-File Report 2012-1051
The 2005 hurricane season was devastating for the Mississippi Gulf Coast. Hurricane Katrina caused significant degradation of the barrier islands that compose the Gulf Islands National Seashore (GUIS). Because of the ability of coastal barrier islands to help mitigate hurricane damage to the mainland, restoring these habitats prior to the...
Detecting drawdowns masked by environmental stresses with water-level models
C.A. Garcia, K. J. Halford, J.M. Fenelon
2013, Ground Water (51) 322-332
Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested...
Presence-only modeling using MAXENT: when can we trust the inferences?
Charles B. Yackulic, Richard Chandler, Elise F. Zipkin, J. Andrew Royle, James D. Nichols, Evan H. Campbell Grant, Sophie Veran
2013, Methods in Ecology and Evolution (4) 236-243
1. Recently, interest in species distribution modelling has increased following the development of new methods for the analysis of presence-only data and the deployment of these methods in user-friendly and powerful computer programs. However, reliable inference from these powerful tools requires that several assumptions be met, including the assumptions that...
Extending airborne electromagnetic surveys for regional active layer and permafrost mapping with remote sensing and ancillary data, Yukon Flats ecoregion, central Alaska
Neal J. Pastick, M. Torre Jorgenson, Bruce K. Wylie, Burke J. Minsley, Lei Ji, Michelle Ann Walvoord, Bruce D. Smith, Jared D. Abraham, Joshua R. Rose
2013, Permafrost and Periglacial Processes (24) 184-199
Machine-learning regression tree models were used to extrapolate airborne electromagnetic resistivity data collected along flight lines in the Yukon Flats Ecoregion, central Alaska, for regional mapping of permafrost. This method of extrapolation (r = 0.86) used subsurface resistivity, Landsat Thematic Mapper (TM) at-sensor reflectance, thermal, TM-derived spectral indices, digital elevation models and...
Spatial consistency of chinook salmon redd distribution within and among years in the Cowlitz River, Washington
Katherine J.C. Klett, Christian E. Torgersen, Julie A. Henning, Christopher J. Murray
2013, North American Journal of Fisheries Management (33) 508-518
We investigated the spawning patterns of Chinook Salmon Oncorhynchus tshawytscha on the lower Cowlitz River, Washington, using a unique set of fine- and coarse-scale temporal and spatial data collected during biweekly aerial surveys conducted in 1991–2009 (500 m to 28 km resolution) and 2008–2009 (100–500 m resolution). Redd locations were...
Spatial capture-recapture models for jointly estimating population density and landscape connectivity
J. Andrew Royle, Richard B. Chandler, Kimberly D. Gazenski, Tabitha A. Graves
2013, Ecology (94) 287-294
Population size and landscape connectivity are key determinants of population viability, yet no methods exist for simultaneously estimating density and connectivity parameters. Recently developed spatial capture–recapture (SCR) models provide a framework for estimating density of animal populations but thus far have not been used to study connectivity. Rather, all applications...
Including independent estimates and uncertainty to quantify total abundance of fish migrating in a large river system: walleye (Sander vitreus) in the Maumee River, Ohio
Jeremy J. Pritt, Mark R. DuFour, Christine M. Mayer, Patrick M. Kocovsky, Jeffrey T. Tyson, Eric J. Weimer, Christopher S. Vandergoot
2013, Canadian Journal of Fisheries and Aquatic Sciences (70) 803-814
Walleye (Sander vitreus) in Lake Erie is a valuable and migratory species that spawns in tributaries. We used hydroacoustic sampling, gill net sampling, and Bayesian state-space modeling to estimate the spawning stock abundance, characterize size and sex structure, and explore environmental factors cuing migration of walleye in the Maumee River...
Great Lakes rivermouths: a primer for managers
Victoria Pebbles, James Larson, Paul Seelbach
Victoria Pebbles, James Larson, Paul Seelbach, editor(s)
2013, Report
Between the North American Great Lakes and their tributaries are the places where the confluence of river and lake waters creates a distinct ecosystem: the rivermouth ecosystem. Human development has often centered around these rivermouths, in part, because they provide a rich array of ecosystem services. Not surprisingly, centuries of...
Martian fluvial conglomerates at Gale Crater
Rebecca M.E. Williams, J.P. Grotzinger, W. E. Dietrich, S. Gupta, D.Y. Sumner, R. C. Wiens, N. Mangold, M. C. Malin, K.S. Edgett, S. Maurice, O. Forni, O. Gasnault, A. Ollila, Horton E. Newsom, G. Dromart, M.C. Palucis, R.A. Yingst, Ryan B. Anderson, Kenneth E. Herkenhoff, S. Le Mouélic, W. Goetz, M.B. Madsen, A. Koefoed, J.K. Jensen, J.C. Bridges, S.P. Schwenzer, K.W. Lewis, K.M. Stack, D. Rubin, L.C. Kah, J.F. Bell III, J.D. Farmer, R. Sullivan, T. Van Beek, D.L. Blaney, O. Pariser, R.G. Deen
2013, Science (340) 1068-1072
Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show...
The SCEC geodetic transient detection validation exercise
Rowena B. Lohman, Jessica R. Murray
2013, Seismological Research Letters (84) 419-425
Over the past decade the number and size of continuously operating Global Positioning System (GPS) networks has grown substantially worldwide. A steadily increasing volume of freely available GPS measurements, combined with the application of new approaches for mining these data for signals of interest, has led to the identification of...
Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions
Tamara J. Zelikova, Ruth A. Hufbauer, Sasha C. Reed, Timothy M. Wertin, Christa Fettig, Jayne Belnap
2013, Ecology and Evolution (3) 1374-1387
How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming...
S-wave triggering of tremor beneath the Parkfield, California, section of the San Andreas fault by the 2011 Tohoku, Japan earthquake: observations and theory
David P. Hill, Zhigang Peng, David R. Shelly, Chastity Aiken
2013, Bulletin of the Seismological Society of America (103) 1541-1550
The dynamic stresses that are associated with the energetic seismic waves generated by the Mw 9.0 Tohoku earthquake off the northeast coast of Japan triggered bursts of tectonic tremor beneath the Parkfield section of the San Andreas fault (SAF) at an epicentral distance of ∼8200 km. The onset of tremor begins...
Modern foraminifera, δ13C, and bulk geochemistry of central Oregon tidal marshes and their application in paleoseismology
Simon E. Engelhart, Benajamin P. Horton, Christopher H. Vane, Alan R. Nelson, Robert C. Witter, Sarah R. Brody, Andrea D. Hawkes
2013, Palaeogeography, Palaeoclimatology, Palaeoecology (377) 13-27
We assessed the utility of δ13C and bulk geochemistry (total organic content and C:N) to reconstruct relative sea-level changes on the Cascadia subduction zone through comparison with an established sea-level indicator (benthic foraminifera). Four modern transects collected from three tidal environments at Siletz Bay, Oregon, USA, produced three elevation-dependent groups...
Mapping landscape phenology preference of yellow-billed cuckoo with AVHRR data
Cynthia S.A. Wallace, Miguel L. Villarreal, Charles van Riper III
2013, Conference Paper, Merging science and management in a rapidly changing world: Biodiversity and management of the Madrean Archipelago III and 7th Conference on Research and Resource Management in the Southwestern Deserts; 2012 May 1-5; Tucson, AZ
We mapped habitat for threatened Yellow-billed Cuckoo (Coccycus americanus occidentalis) in the State of Arizona using the temporal greenness dynamics of the landscape, or the landscape phenology. Landscape phenometrics were derived from Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) data for 1998 and 1999 by using...
Assessing factors affecting the thermal properties of a passive thermal refuge using three-dimensional hydrodynamic flow and transport modeling
Jeremy D. Decker, Eric D. Swain, Bradley Stith, Catherine A. Langtimm
2013, Journal of Waterway, Port, Coastal, Ocean Engineering (139) 209-220
Everglades restoration activities may cause changes to temperature and salinity stratification at the Port of the Islands (POI) marina, which could affect its suitability as a cold weather refuge for manatees. To better understand how the Picayune Strand Restoration Project (PSRP) may alter this important resource in Collier County in...
Hydrogen isotope investigation of amphibole and glass in dacite magmas erupted in 1980-1986 and 2005 at Mount St. Helens, Washington
S.J. Underwood, T.C. Feeley, M.A. Clynne
2013, Journal of Petrology
In active, shallow, sub-volcanic magma conduits the extent of the dehydrogenation–oxidation reaction in amphibole phenocrysts is controlled by energetic processes that cause crystal lattice damage or conditions that increase hydrogen diffusivity in magmatic phases. Amphibole phenocrysts separated from dacitic volcanic rocks erupted from 1980 to 1986 and in 2005 at...
