Foraging patterns of Caspian terns and double-crested cormorants in the Columbia River estuary
Donald E. Lyons, D.D. Roby, K. Collis
2007, Northwest Science (81) 91-103
We examined spatial and temporal foraging patterns of Caspian terns and double-crested cormorants nesting in the Columbia River estuary, to potentially identify circumstances where juvenile salmonids listed under the U.S. Endangered Species Act might be more vulnerable to predation by these avian piscivores. Data were collected during the 1998 and...
Influence of tectonic folding on rockfall susceptibility, American Fork Canyon, Utah, USA
J. A. Coe, E. L. Harp
2007, Natural Hazards and Earth System Sciences (7) 1-14
We examine rockfall susceptibility of folded strata in the Sevier fold-thrust belt exposed in American Fork Canyon in north-central Utah. Large-scale geologic mapping, talus production data, rock-mass-quality measurements, and historical rockfall data indicate that rockfall susceptibility is correlated with limb dip and curvature of the folded, cliff-forming Mississippian limestones. On...
Ground-penetrating radar: A tool for monitoring bridge scour
N.L. Anderson, A.M. Ismael, T. Thitimakorn
2007, Environmental & Engineering Geoscience (13) 1-10
Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom,...
Modelingevapotranspirationina sub-tropical climate
M.R. Savabi, T.A. Cochrane, E. German, C. Ikiz, N. Cockshutt
2007, Journal of Environmental Hydrology (15) 1-15
Evapotranspiration (ET) loss is estimated at about 80-85% of annual precipitation in South Florida. Accurate prediction of ET is important during and beyond the implementation of the Comprehensive Everglades Restoration Plan (CERP). In the USDA's Everglades Agro-Hydrology Model (EAHM) the soil water intake is linked with the soil water redistribution,...
Surface drifter derived circulation in the northern and middle Adriatic Sea: Response to wind regime and season
L. Ursella, P.-M. Poulain, R. P. Signell
2007, Journal of Geophysical Research C: Oceans (112)
More than 120 satellite-tracked drifters were deployed in the northern and middle Adriatic (NMA) Sea between September 2002 and November 2003, with the purpose of studying the surface circulation at mesoscale to seasonal scale in relation to wind forcing, river runoff, and bottom topography. Pseudo-Eulerian and Lagrangian statistics were calculated...
Prioritizing bottomland hardwood forest sites for protection and augmentation
J. Carter, J. Biagas
2007, Natural Areas Journal (27) 72-82
Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these...
Spatial and temporal migration patterns of Wilson's Warbler (Wilsonia pusilla) in the southwest as revealed by stable isotopes
K.L. Paxton, Charles van Riper III, T.C. Theimer, E. H. Paxton
2007, The Auk (124) 162-175
We used stable hydrogen isotopes (δD) to identify the breeding locations of Wilson’s Warbler (Wilsonia pusilla) migrating through five sites spanning a cross-section of the species’ southwestern migration route during the springs of 2003 and 2004. Determining the temporal and spatial patterns of migration and degree of population segregation during...
Morphological variation of siscowet lake trout in Lake Superior
C.R. Bronte, S.A. Moore
2007, Transactions of the American Fisheries Society (136) 509-517
Historically, Lake Superior has contained many morphologically distinct forms of the lake trout Salvelinus namaycush that have occupied specific depths and locations and spawned at specific times of the year. Today, as was probably the case historically, the siscowet morphotype is the most abundant. Recent interest in harvesting siscowets to extract oil...
Toward a transport-based analysis of nutrient spiraling and uptake in streams
Robert L. Runkel
2007, Limnology and Oceanography: Methods (5) 50-62
Nutrient addition experiments are designed to study the cycling of nutrients in stream ecosystems where hydrologic and nonhydrologic processes determine nutrient fate. Because of the importance of hydrologic processes in stream ecosystems, a conceptual model known as nutrient spiraling is frequently employed. A central part of the nutrient spiraling approach...
Evidence of widespread natural reproduction by lake trout Salvelinus namaycush in the Michigan waters of Lake Huron
S.C. Riley, J.X. He, J.E. Johnson, T. P. O’Brien, J.S. Schaeffer
2007, Journal of Great Lakes Research (33) 917-921
Localized natural reproduction of lake trout Salvelinus namaycush in Lake Huron has occurred since the 1980s near Thunder Bay, Michigan. During 2004–2006, USGS spring and fall bottom trawl surveys captured 63 wild juvenile lake trout at depths ranging from 37–73 m at four of five ports in the Michigan waters of the...
Regional beach/cliff system dynamics along the california coast
C.J. Hapke, Don Reid
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
The coast of California is comprised of both sandy shorelines and cliffed coastline, and in many areas these features spatially coincide. In order to better understand the regional trends of change along the California coast, the U.S. Geological Survey is quantifying both sandy shoreline change and coastal cliff retreat for...
Late quaternary paleoseismology of the southern Steens fault zone, northern Nevada
S. F. Personius, A. J. Crone, M. N. Machette, S. A. Mahan, J.B. Kyung, H. Cisneros, D. J. Lidke
2007, Bulletin of the Seismological Society of America (97) 1662-1678
The 192-km-long Steens fault zone is the most prominent normal fault system in the northern Basin and Range province of western North America. We use trench mapping and radiometric dating to estimate displacements and timing of the last three surface-rupturing earthquakes (E1-E3) on the southern part of the fault south...
Is statistical power to detect trends a good assessment of population monitoring?
N.E. Seavy, M.H. Reynolds
2007, Biological Conservation (140) 187-191
The ability to detect trends in population abundance is of obvious interest to wildlife managers. In recent years, the probability of detecting defined population trends has been the most common method of assessing monitoring programs. Such analyses require many assumptions, including a model for population change and a model for...
Random forests for classification in ecology
D.R. Cutler, T.C. Edwards Jr., K.H. Beard, A. Cutler, K.T. Hess, J. Gibson, J.J. Lawler
2007, Ecology (88) 2783-2792
Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy;...
Adequacy of satellite derived rainfall data for stream flow modeling
G. Artan, Hussein Gadain, Jodie Smith, Kwasi Asante, C.J. Bandaragoda, J. P. Verdin
2007, Natural Hazards (43) 167-185
Floods are the most common and widespread climate-related hazard on Earth. Flood forecasting can reduce the death toll associated with floods. Satellites offer effective and economical means for calculating areal rainfall estimates in sparsely gauged regions. However, satellite-based rainfall estimates have had limited use in flood forecasting and hydrologic stream...
Quantification of changes in metal loading from storm runoff, Merse River (Tuscany, Italy)
Briant A. Kimball, F. Bianchi, Katherine Walton-Day, Robert L. Runkel, M. Nannucci, A. Salvadori
2007, Mine Water and the Environment (26) 209-216
The Merse River in Tuscany is affected by mine drainage and the weathering of mine wastes along several kilometres of its catchment. The metal loading to the stream was quantified by defining detailed profiles of discharge and concentration, using tracer-dilution and synoptic-sampling techniques. During the course of a field experiment...
A rangewide population genetic study of trumpeter swans
S.J. Oyler-McCance, F.A. Ransler, L.K. Berkman, T.W. Quinn
2007, Conservation Genetics (8) 1339-1353
For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions...
Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark
K. Hinsby, Anker L. Højberg, P. Engesgaard, K.H. Jensen, F. Larsen, Niel Plummer, Eurybiades Busenberg
2007, Water Resources Research (43)
Vertical profiles of the chlorofluorocarbons CFC‐11, CFC‐12, and CFC‐113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the <1 m thick transition zone from aerobic to anaerobic groundwater in a pyritic sand aquifer at Rabis Creek, Denmark. Two‐dimensional solute transport...
Near-fault peak ground velocity from earthquake and laboratory data
Art McGarr, Joe B. Fletcher
2007, Bulletin of the Seismological Society of America (97) 1502-1510
We test the hypothesis that peak ground velocity (PGV) has an upper bound independent of earthquake magnitude and that this bound is controlled primarily by the strength of the seismogenic crust. The highest PGVs, ranging up to several meters per second, have been measured at sites within a few kilometers...
Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA
P.W. Swarzenski, F. W. Simonds, A.J. Paulson, S. Kruse, C. Reich
2007, Environmental Science & Technology (41) 7022-7029
Geochemical tracer data (i.e., 222Rn and four naturally occurring Ra isotopes), electromagnetic (EM) seepage meter results, and high-resolution, stationary electrical resistivity images were used to examine the bi-directional (i.e., submarine groundwater discharge and recharge) exchange of a coastal aquifer with seawater. Our study site for these experiments was Lynch Cove,...
Near-infrared spectral mapping of Titan's mountains and channels
Jason W. Barnes, Jani Radebaugh, Robert H. Brown, Steve Wall, Laurence A. Soderblom, Jonathan I. Lunine, Devon M. Burr, Christophe Sotin, Stephane Le Mouelic, Sebastien Rodriguez, Bonnie J. Buratti, Roger N. Clark, Kevin H. Baines, Ralf Jaumann, Philip D. Nicholson, Randolph L. Kirk, Rosaly Lopes, Ralph D. Lorenz, Ken Mitchell, Charles A. Wood
2007, Journal of Geophysical Research E: Planets (112)
We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument during...
Selection of spawning sites by coho salmon in a northern California stream
K.E. Mull, M.A. Wilzbach
2007, North American Journal of Fisheries Management (27) 1343-1354
We assessed the relative importance of various factors contributing to spawning site use by a population of threatened coho salmon Oncorhynchus kisutch in Freshwater Creek, California, and created a predictive model of spawning habitat selection based on logistic regression analysis. We excluded sampling sites that previous studies had established as...
An analysis of urban development and its environmental impact on the Tampa Bay watershed
G. Xian, M. Crane, J. Su
2007, Journal of Environmental Management (85) 965-976
Urbanization has transformed natural landscapes into anthropogenic impervious surfaces. Urban land use has become a major driving force for land cover and land use change in the Tampa Bay watershed of west-central Florida. This study investigates urban land use change and its impact on the watershed. The spatial and temporal...
Evaluation of abutment scour prediction equations with field data
S.T. Benedict, N. Deshpande, N.M. Aziz
2007, Transportation Research Record 118-126
The U.S. Geological Survey, in cooperation with FHWA, compared predicted abutment scour depths, computed with selected predictive equations, with field observations collected at 144 bridges in South Carolina and at eight bridges from the National Bridge Scour Database. Predictive equations published in the 4th edition of Evaluating Scour at Bridges...
A multi-scale segmentation approach to filling gaps in Landsat ETM+ SLC-off images
S.K. Maxwell, Gail L. Schmidt, James C. Storey
2007, International Journal of Remote Sensing (28) 5339-5356
On 31 May 2003, the Landsat Enhanced Thematic Plus (ETM+) Scan Line Corrector (SLC) failed, causing the scanning pattern to exhibit wedge-shaped scan-to-scan gaps. We developed a method that uses coincident spectral data to fill the image gaps. This method uses a multi-scale segment model, derived from a previous Landsat...
