The effects of habitat resolution on models of avian diversity and distributions: A comparison of two land-cover classifications
Joshua J. Lawler, Raymond. J. O’Connor, Carolyn T. Hunsaker, K. Bruce Jones, Thomas R. Loveland, Denis White
2004, Landscape Ecology (19) 517-532
Quantifying patterns is a key element of landscape analysis. One aspect of this quantification of particular importance to landscape ecologists is the classification of continuous variables to produce categorical variables such as land-cover type or elevation stratum. Although landscape ecologists are fully aware of the importance of spatial resolution in...
Predicting patterns of non-native plant invasions in Yosemite National Park, California, USA
E.C. Underwood, R. Klinger, P.E. Moore
2004, Diversity and Distributions (10) 447-459
One of the major issues confronting management of parks and reserves is the invasion of non-native plant species. Yosemite National Park is one of the largest and best-known parks in the United States, harbouring significant cultural and ecological resources. Effective management of non-natives would be greatly assisted by information on...
Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation
William L. Gale, A.G. Maule, A. Postera, M.H. Peters
2004, River Research and Applications (20) 565-576
At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved...
Mineral resource of the month: copper
Daniel L. Edelstein
2004, Geotimes (2004)
Beryllium metal is lighter than aluminum and stiffer than steel. These and other properties, including its strength, dimensional stability, thermal properties and reflectivity, make it useful for aerospace and defense applications, such as satellite and space-vehicle structural components. Beryllium’s nuclear properties, combined with its low density, make it useful as...
The Modular Modeling System (MMS): A modeling framework for water- and environmental-resources management
G.H. Leavesley, S.L. Markstrom, Roland J. Viger
2004, Conference Paper, Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001
The interdisciplinary nature and increasing complexity of water- and environmental-resource problems require the use of modeling approaches that can incorporate knowledge from a broad range of scientific disciplines. The large number of distributed hydrological and ecosystem models currently available are composed of a variety of different conceptualizations of the associated...
Modeling the Death Valley regional ground-water flow system
F. A. D’Agnese, C.C. Faunt, M. C. Hill
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
The development of a regional ground-water flow model of the Death Valley region in the southwestern United States is discussed in the context of the fourteen guidelines of Hill. This application of the guidelines demonstrates how they may be used for model calibration and evaluation, and to direct further model...
Simulating the effects of ground-water withdrawals on streamflow in a precipitation-runoff model
Philip J. Zarriello, P. M. Barlow, P.B. Duda
2004, Conference Paper, Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001
Precipitation-runoff models are used to assess the effects of water use and management alternatives on streamflow. Often, ground-water withdrawals are a major water-use component that affect streamflow, but the ability of surface-water models to simulate ground-water withdrawals is limited. As part of a Hydrologic Simulation Program-FORTRAN (HSPF) precipitation-runoff model developed...
A web-enabled system for integrated assessment of watershed development
R. Dymond, V. Lohani, B. Regmi, R. Dietz
2004, Conference Paper, Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001
Researchers at Virginia Tech have put together the primary structure of a web enabled integrated modeling system that has potential to be a planning tool to help decision makers and stakeholders in making appropriate watershed management decisions. This paper describes the integrated system, including data sources, collection, analysis methods, system...
Methods and guidelines for effective model calibration
M. C. Hill
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
This paper briefly describes nonlinear regression methods, a set of 14 guidelines for model calibration, how they are implemented in and supported by two public domain computer programs, and a demonstration and a test of the methods and guidelines. Copyright ASCE 2004....
Flood hydrology for Dry Creek, Lake County, Northwestern Montana
C. Parrett, R.D. Jarrett
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
Dry Creek drains about 22.6 square kilometers of rugged mountainous terrain upstream from Tabor Dam in the Mission Range near St. Ignatius, Montana. Because of uncertainty about plausible peak discharges and concerns regarding the ability of the Tabor Dam spillway to safely convey these discharges, the flood hydrology for Dry...
Using borehole flow data to characterize the hydraulics of flow paths in operating wellfields
F. Paillet, J. Lundy
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
Understanding the flow paths in the vicinity of water well intakes is critical in the design of effective wellhead protection strategies for heterogeneous carbonate aquifers. High-resolution flow logs can be combined with geophysical logs and borehole-wall-image logs (acoustic televiewer) to identify the porous beds, solution openings, and fractures serving as...
Local sediment scour model tests for the Woodrow Wilson Bridge piers
D.M. Sheppard, J.S. Jones, M. Odeh, T. Glasser
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
The Woodrow Wilson Bridge on I-495 over the Potomac River in Prince Georges County, Maryland is being replaced. Physical local scour model studies for the proposed piers for the new bridge were performed in order to help establish design scour depths. Tests were conducted in two different flumes, one in...
Evaluating observations in the context of predictions for the death valley regional groundwater system
D.M. Ely, M. C. Hill, C. R. Tiedeman, G. M. O’Brien
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
When a model is calibrated by nonlinear regression, calculated diagnostic and inferential statistics provide a wealth of information about many aspects of the system. This work uses linear inferential statistics that are measures of prediction uncertainty to investigate the likely importance of continued monitoring of hydraulic head to the accuracy...
Source and redox controls on metallogenic variations in intrusion-related ore systems, Tombstone-Tungsten Belt, Yukon Territory, Canada
C.J.R. Hart, J.L. Mair, R.J. Goldfarb, D.I. Groves
2004, Conference Paper, Special Paper of the Geological Society of America
The Tombstone, Mayo and Tungsten plutonic suites of granitic intrusions, collectively termed the Tombstone-Tungsten Belt, form three geographically, mineralogically, geochemically and metallogenically distinct plutonic suites. The granites (sensu lato) intruded the ancient North American continental margin of the northern Canadian Cordillera as part of a single magmatic episode in the...
Simulation of an urban ground-water-flow system in the Menomonee Valley, Milwaukee, Wisconsin using analytic element modeling
C. P. Dunning, D. T. Feinstein
2004, Conference Paper, Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001
A single-layer, steady-state analytic element model was constructed to simulate shallow ground-water flow in the Menomonee Valley, an old industrial center southwest of downtown Milwaukee, Wisconsin. Project objectives were to develop an understanding of the shallow ground-water flow system and identify primary receptors of recharge to the valley. The analytic...
Monograph for using paleoflood data in Water Resources Applications
R.E. Swain, R.D. Jarrett
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
The Environmental and Water Resources Institute (EWRI) Technical Committee on Surface Water Hydrology is sponsoring a Task Committee on Paleoflood Hydrology to prepare a monograph entitled, "Use of Paleoflood and Historical Data in Water Resources Applications." This paper introduces the subject of paleoflood hydrology and discusses the topics, which are...
Hydraulic modeling and scour analysis for the San Francisco - Oakland Bay Bridge
J.G. Shelden, E.D. Smith, D.M. Sheppard, M. Odeh
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
A study was conducted to determine potential maximum scour depths for the foundations of the replacement east span of the San Francisco-Oakland Bay Bridge, as part of the ongoing structural design. This effort presented unique challenges as strong tidal currents, large depths, and cohesive bottom sediments characterize the site. The...
Improving wetland simulations by including heat transport in groundwater flow modeling
Hector R. Bravo, F. Jiang, R. J. Hunt
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
A procedure was developed to automatically calibrate a groundwater flow and heat transport model, resulting in the estimation of hydraulic conductivity and flux across the water table in wetland systems. This paper describes differences between previous approaches and this study, and summarizes some challenges in the method implementation. The procedure...
Natural Attenuation Software (NAS): A computer program for estimating remediation times of contaminated groundwater
E. Mendez, M. Widdowson, S. Brauner, F. Chapelle, C. Casey
Latini G.Passerini G.Brebbia C.A., editor(s)
2004, Conference Paper, Environmental Studies
This paper describes the development and application of a modeling system called Natural Attenuation Software (NAS). NAS was designed as a screening tool to estimate times of remediation (TORs), associated with monitored natural attenuation (MNA), to lower groundwater contaminant concentrations to regulatory limits. Natural attenuation processes that NAS models include...
Hydrologic processes in deep vadose zones in interdrainage arid environments
Michelle Ann Walvoord, Bridget R. Scanlon
James F. Hogan, Fred M. Phillips, Bridget R. Scanlon, editor(s)
2004, Book chapter, Groundwater recharge in a desert environment: The southwestern United States (Water Science and Application, no. 9)
A unifying theory for the hydrology of desert vadose zones is particularly timely considering the rising population and water stresses in arid and semiarid regions. Conventional models cannot reconcile the apparent discrepancy between upward flow indicated by hydraulic gradient data and downward flow suggested by environmental tracer data in deep...
Holocene alluvium around Lefkosia (Nicosia), Cyprus: An archive of land-use, tectonic processes, and climate change
Wayne L. Newell, B. Stone, R. Harrison
Martin-Duque J.F.Brebbia C.A.Godfrey A.E.Diaz de Teran J.R., editor(s)
2004, Conference Paper, Geo-Environment: Monitoring and Remedation of the Geological Environment
Holocene alluvium of the Pedhicos River around Lefkosia (Nicosia), Cyprus, was studied. Alluvial stratigraphy was found to present serial flood deposits underlying river terraces and an extensive alluvial fan. It was found that the stratigraphy and geomorphology of the alluvium can be interpreted to distinguish not only the effects of...
Inhibition and enhancement of microbial surface colonization: the role of silicate composition
Jennifer A. Roberts
2004, Chemical Geology (212) 313-327
Classical treatment of cell attachment by models of filtration or coulombic attraction assumes that attachment of cells to mineral surfaces would be controlled by factors such as response to predation, collision efficiency, or coulombic attraction between the charged groups at the mineral and cell surfaces. In the study reported here,...
Object-based inversion of crosswell radar tomography data to monitor vegetable oil injection experiments
John W. Lane Jr., Frederick D. Day-Lewis, Roelof J. Versteeg, Clifton C. Casey
2004, Journal of Environmental & Engineering Geophysics (9) 63-77
Crosswell radar methods can be used to dynamically image ground-water flow and mass transport associated with tracer tests, hydraulic tests, and natural physical processes, for improved characterization of preferential flow paths and complex aquifer heterogeneity. Unfortunately, because the raypath coverage of the interwell region is limited by the borehole...
Transport and time lag of chlorofluorocarbon gases in the unsaturated zone, Rabis Creek, Denmark
Peter Engesgaard, Anker L. Højberg, Klaus Hinsby, Karsten H. Jensen, Troels Laier, Flemming Larsen, Eurybiades Busenberg, Niel Plummer
2004, Vadose Zone Journal (3) 1249-1261
Transport of chlorofluorocarbon (CFC) gases through the unsaturated zone to the water table is affected by gas diffusion, air–water exchange (solubility), sorption to the soil matrix, advective–dispersive transport in the water phase, and, in some cases, anaerobic degradation. In deep unsaturated zones, this may lead to a time lag between...
Reach-scale cation exchange controls on major ion chemistry of an Antarctic glacial meltwater stream
Michael N. Gooseff, Diane M. McKnight, Robert L. Runkel
2004, Aquatic Geochemistry (10) 221-238
McMurdo dry valleys of Antarctica represent the largest of the ice-free areas on the Antarctic continent, containing glaciers, meltwater streams, and closed basin lakes. Previous geochemical studies of dry valley streams and lakes have addressed chemical weathering reactions of hyporheic substrate and geochemical evolution of dry valley surface waters. We...
