In situ determination of particle friction angles of fluvial gravels
Christopher E. Johnston, E.D. Andrews, John Pitlick
1998, Water Resources Research (34) 2017-2030
Particle friction angles Φ represent the physical resistance to initial movement of a sediment particle and are therefore useful for relating initiation of motion to particular flows. We determined over 8000 friction angle values at five natural rivers by applying a new method that uses a digital load cell to...
Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca
Chris G. Ingersoll, Eric L. Brunson, F. James Dwyer, Douglas K. Hardesty, Nile E. Kemble
1998, Environmental Toxicology and Chemistry (17) 1508-1523
Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with...
Coseismic temporal changes of slip direction: The effect of absolute stress on dynamic rupture
Mariagiovanna Guatteri, P. Spudich
1998, Bulletin of the Seismological Society of America (88) 777-789
We investigate the dynamics of rupture at low-stress level. We show that one main difference between the dynamics of high- and low-stress events is the amount of coseismic temporal rake rotation occurring at given points on the fault. Curved striations on exposed fault surfaces and earthquake dislocation models derived from...
Simulation of variable-density flow and transport of reactive and nonreactive solutes during a tracer test at Cape Cod, Massachusetts
Hubao Zhang, Frank W. Schwartz, Warren W. Wood, S. P. Garabedian, D.R. LeBlanc
1998, Water Resources Research (34) 67-82
A multispecies numerical code was developed to simulate flow and mass transport with kinetic adsorption in variable-density flow systems. The two-dimensional code simulated the transport of bromide (Br−), a nonreactive tracer, and lithium (Li+), a reactive tracer, in a large-scale tracer test performed in a sand-and-gravel aquifer at Cape Cod,...
Comparison of hydrochemical tracers to estimate source contributions to peak flow in a small, forested, headwater catchment
Karen C. Rice, George M. Hornberger
1998, Water Resources Research (34) 1755-1766
Three-component (throughfall, soil water, groundwater) hydrograph separations at peak flow were performed on 10 storms over a 2-year period in a small forested catchment in north-central Maryland using an iterative and an exact solution. Seven pairs of tracers (deuterium and oxygen 18, deuterium and chloride, deuterium and sodium, deuterium and...
Operational modeling system with dynamic-wave routing
A. L. Ishii, T.J. Charlton, T.W. Ortel, C.C. Vonnahme
Loucks E, editor(s)
1998, Conference Paper, Proceedings of the Annual Water Resources Planning and Management Conference
A near real-time streamflow-simulation system utilizing continuous-simulation rainfall-runoff generation with dynamic-wave routing is being developed by the U.S. Geological Survey in cooperation with the Du Page County Department of Environmental Concerns for a 24-kilometer reach of Salt Creek in Du Page County, Illinois. This system is needed in order to...
Before and after retrofit - response of a building during ambient and strong motions
M. Çelebi, Huaibao P. Liu
Jones N.P., editor(s)
1998, Journal of Wind Engineering and Industrial Aerodynamics (77-78) 259-268
This paper presents results obtained from ambient vibration and strong-motion responses of a thirteen-story, moment-resisting steel framed Santa Clara County Office Building (SCCOB) before being retrofitted by visco-elastic dampers and from ambient vibration response following the retrofit. Understanding the cumulative structural and site characteristics that affect the response of SCCOB...
Integrating ecosystem studies: A Bayesian comparison of hypotheses
Milo D. Adkison, Brenda E. Ballachey, James L. Bodkin, Leslie E. Holland-Bartels
F. Funk, T.J. Quinn II, J. Heifetz, J.N. Ianelli, J.E. Powers, J.F. Schweigert, P.J. Sullivan, C.-I. Zhang, editor(s)
1998, Conference Paper, Proceedings of the international symposium on fishery stock assessment models for the 21st century; 15th Lowell Wakefield fisheries symposium
Ecosystem studies are difficult to interpret because of the complexity and number of pathways that may affect a phenomenon of interest. It is not possible to study all aspects of a problem; thus subjective judgment is required to weigh what has been observed in the context of components that were...
Modeling and management of water in the Klamath River Basin: overcoming politics and conflicts
Marshall Flug, John F. Scott
Steven R. Abt, Jayne Young-Pezeshk, Chester C. Watson, editor(s)
1998, Conference Paper, Water resources engineering 98: Proceedings of the International Water Resources Engineering Conference
The network flow model MODSIM, which was designed as a water quantity mass balance model for evaluating and selecting water management alternatives, has been applied to the Klamath River basin. A background of conflicting issues in the basin is presented. The complexity of water quantity model development, while satisfying the...
An individual-based, spatially-explicit simulation model of the population dynamics of the endangered red-cockaded woodpecker, Picoides borealis
B. H. Letcher, J.A. Priddy, J. R. Walters, L.B. Crowder
1998, Biological Conservation (86) 1-14
Spatially-explicit population models allow a link between demography and the landscape. We developed a spatially-explicit simulation model for the red-cockaded woodpecker, Picoides borealis, an endangered and territorial cooperative breeder endemic to the southeastern United States. This kind of model is especially appropriate for this species because it can incorporate the spatial...
Investigating flight response of Pacific brant to helicopters at Izembek Lagoon, Alaska by using logistic regression
Wallace P. Erickson, Todd G. Nick, David H. Ward
Roxy Peck, Larry D. Haugh, Arnold Goodman, editor(s)
1998, Book chapter, Statistical case studies: A collaboration between academe and industry
Izembek Lagoon, an estuary in Alaska, is a very important staging area for Pacific brant, a small migratory goose. Each fall, nearly the entire Pacific Flyway population of 130,000 brant flies to Izembek Lagoon and feeds on eelgrass to accumulate fat reserves for nonstop transoceanic migration to wintering areas as...
Great Lakes
Thomas A. Edsall
Michael J. Mac, Paul A. Opler, Catherine E. Puckett Haecker, Peter D. Doran, editor(s)
1998, Book chapter, Status and trends of the nation's biological resources
The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside...
Effects of a delayed onset of piscivory on the size of age-0 bluefish
J.A. Buckel, B. H. Letcher, D.O. Conover
1998, Transactions of the American Fisheries Society (127) 576-587
Variation in advection or other physical forces may accelerate or delay arrival of young marine fishes into productive nearshore habitats, thereby affecting the length of the available growing season. The bluefish Pomatomus saltatrix is an oceanic spawner whose juvenile stages, upon entry into estuarine waters, become piscivorous and thereby experience greatly increased growth. <span...
Estimating maize production in Kenya using NDVI: Some statistical considerations
J.E. Lewis, James Rowland, A. Nadeau
1998, International Journal of Remote Sensing (19) 2609-2617
A regression model approach using a normalized difference vegetation index (NDVI) has the potential for estimating crop production in East Africa. However, before production estimation can become a reality, the underlying model assumptions and statistical nature of the sample data (NDVI and crop production) must be examined rigorously. Annual maize...
Satellite radar interferometry measures deformation at Okmok Volcano
Zhong Lu, Dorte Mann, Jeff Freymueller
1998, Eos, Transactions, American Geophysical Union (79) 461-468
The center of the Okmok caldera in Alaska subsided 140 cm as a result of its February– April 1997 eruption, according to satellite data from ERS-1 and ERS-2 synthetic aperture radar (SAR) interferometry. The inferred deflationary source was located 2.7 km beneath the approximate center of the caldera using a...
Suitability of parametric models to describe the hydraulic properties of an unsaturated coarse sand and gravel
Andy Mace, David L. Rudolph, R. Gary Kachanoski
1998, Groundwater (36) 465-475
The performance of parametric models used to describe soil water retention (SWR) properties and predict unsaturated hydraulic conductivity (K) as a function of volumetric water content (θ) is examined using SWR and K(θ) data for coarse sand and gravel sediments. Six 70 cm long, 10 cm diameter cores of glacial...
Cultural resource applications for a GIS: Stone conservation at Jefferson and Lincoln Memorials
Kyle Joly, Tony Donald, Douglas Comer
1998, Cultural Resources Management (21) 17-18
Geographical information systems are rapidly becoming essential tools for land management. They provide a way to link landscape features to the wide variety of information that managers must consider when formulating plans for a site, designing site improvement and restoration projects, determining maintenance projects and protocols, and even interpreting the...
Responses of brown bears to human activities at O'Malley River, Kodiak Island, Alaska
Gregory A. Wilker, Victor G. Barnes Jr.
1998, Ursus (10) 557-561
We classified levels of direct response of brown bears (Ursus arctos middendorffi) to aircraft, watercraft, and groups of people on the O'Malley River area of Kodiak Island, Alaska. General public use occurred on the area in 1991 and 1993, whereas structured bear viewing programs used the area in 1992 and...
Regional land cover characterization using Landsat thematic mapper data and ancillary data sources
James E. Vogelmann, Terry L. Sohl, P.V. Campbell, D.M. Shaw
Veith G., editor(s)
1998, Environmental Monitoring and Assessment (51) 415-428
As part of the activities of the Multi-Resolution Land Characteristics (MRLC) Interagency Consortium, an intermediate-scale land cover data set is being generated for the conterminous United States. This effort is being conducted on a region-by-region basis using U.S. Standard Federal Regions. To date, land cover data sets have been...
Modeling spatial distribution of the Unionid mussels and the core-satellite hypothesis
Hooi-Ling Lee, Donald L. DeAngelis, Hock Lye Koh
1998, Water Science and Technology (38) 73-79
This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of...
Seasonal and interannual variations of atmospheric CO2 and climate
M. D. Dettinger, M. Ghil
1998, Tellus, Series B: Chemical and Physical Meteorology (50) 1-24
Interannual variations of atmospheric CO2 concentrations at Mauna Loa are almost masked by the seasonal cycle and a strong trend; at the South Pole, the seasonal cycle is small and is almost lost in the trend and interannual variations. Singular-spectrum analysis (SSA) is used here to isolate and reconstruct interannual signals...
Coupling demography, physiology and evolution in chaparral shrubs,
Jon E. Keeley
P.W. Rundel, G. Montenegro, F.M. Jaksic, editor(s)
1998, Book chapter, Landscape Disturbance and Biodiversity in Mediterranean-Type Ecosystems.
Historically, since fire is a recurrent catastrophic disturbance, mediterranean-climate shrubs have been classified by their mode of postfire regeneration, i.e., obligate seeders, facultative seeders or obligate resprouters. While these terms are useful, they are too restrictive in that they only refer to a species’ response to fire and do not...
Evidence from Lake Baikal for Siberian glaciation during oxygen-isotope substage 5d
E.B. Karabanov, A.A. Prokopenko, D. F. Williams, Steven M. Colman
1998, Quaternary Research (50) 46-55
The paleoclimatic record from bottom sediments of Lake Baikal (eastern Siberia) reveals new evidence for an abrupt and intense glaciation during the initial part of the last interglacial period (isotope substage 5d). This glaciation lasted about 12 000 yr from 117 000 to 105 000 yr BP according to correlation...
Decadal variability of precipitation over Western North America
D.R. Cayan, M. D. Dettinger, Henry F. Diaz, N.E. Graham
1998, Journal of Climate (11) 3148-3166
Decadal (>7- yr period) variations of precipitation over western North America account for 20%-50% of the variance of annual precipitation. Spatially, the decadal variability is broken into several regional [O(1000 km)] components. These decadal variations are contributed by fluctuations in precipitation from seasons of the year that vary from region...
A nowcast model for tides and tidal currents in San Francisco Bay, California
Ralph T. Cheng, Richard E. Smith
1998, Conference Paper
National Oceanographic and Atmospheric Administration (NOAA) installed Physical Oceanographic Real-Time System (PORTS) in San Francisco Bay, California to provide observations of tides, tidal currents, and meteorological conditions. PORTS data are used for optimizing vessel operations, increasing margin of safety for navigation, and guiding hazardous material spill prevention and response. Because...
