Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012
David W. Smith, Susan G. Buto, Toby L. Welborn
2016, Scientific Investigations Report 2016-5045
The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of...
Manual hierarchical clustering of regional geochemical data using a Bayesian finite mixture model
Karl J. Ellefsen, David Smith
2016, Applied Geochemistry (75) 200-210
Interpretation of regional scale, multivariate geochemical data is aided by a statistical technique called “clustering.” We investigate a particular clustering procedure by applying it to geochemical data collected in the State of Colorado, United States of America. The clustering procedure partitions the field samples for the entire survey area into...
Geologic and geophysical models for Osage County, Oklahoma, with implications for groundwater resources
Mark R. Hudson, David V. Smith, Michael P. Pantea, Carol Becker
2016, Scientific Investigations Report 2016-5067
This report summarizes a three-dimensional (3-D) geologic model that was constructed to provide a framework to investigate groundwater resources of the Osage Nation in northeastern Oklahoma. This report also presents an analysis of an airborne electromagnetic (AEM) survey that assessed the spatial variation of electrical resistivity to depths as great...
User’s guide for GcClust—An R package for clustering of regional geochemical data
Karl J. Ellefsen, David B. Smith
2016, Techniques and Methods 7-C13
GcClust is a software package developed by the U.S. Geological Survey for statistical clustering of regional geochemical data, and similar data such as regional mineralogical data. Functions within the software package are written in the R statistical programming language. These functions, their documentation, and a copy of the user’s guide...
Groundwater exchanges near a channelized versus unmodified stream mouth discharging to a subalpine lake
James Constantz, Ramon C. Naranjo, Richard G. Niswonger, Kip K. Allander, B. Neilson, Donald O. Rosenberry, David W. Smith, C. Rosecrans, David A. Stonestrom
2016, Water Resources Research (52) 2157-2177
The terminus of a stream flowing into a larger river, pond, lake, or reservoir is referred to as the stream-mouth reach or simply the stream mouth. The terminus is often characterized by rapidly changing thermal and hydraulic conditions that result in abrupt shifts in surface water/groundwater (sw/gw) exchange patterns, creating the potential for...
Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables
Chris S. Eckley, Michael Tate, Che-Jen Lin, Mae S. Gustin, Stephen Dent, Collin Eagles-Smith, Michelle A. Lutz, Kimberly Wickland, Bronwen Wang, John E. Gray, Grant Edwards, David P. Krabbenhoft, David B. Smith
2016, Science of the Total Environment (568) 651-665
Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis...
Ecoregions of California
Glenn E. Griffith, James M. Omernik, David W. Smith, Terry D. Cook, Ed Tallyn, Kendra Moseley, Colleen B. Johnson
2016, Open-File Report 2016-1021
Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. By recognizing the spatial differences in the capacities and potentials of...
Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment
David Solance Smith, Stephen M. Fettig, Matthew A. Bowker
2016, Forest Ecology and Management (362) 46-54
Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute...
Environmental DNA calibration study interim technical review report December 2014
Kelly Baerwaldt, Meredith L. Bartron, Kurt Schilling, Debbie Lee, Edmond Russo, Trudy Estes, Richard Fischer, Beth Fleming, Michael P. Guilfoyle, Jack Killgore, Richard Lance, Edward Perkins, Martin Schultz, David Smith, Jon J. Amberg, Duane Chapman, Mark P. Gaikowski, Katy E. Klymus, Catherine A. Richter
2015, Report
The Environmental DNA Calibration Study (ECALS) is a multi-year study to improve the understanding and interpretation of the detection of Asian carp DNA in environmental samples (eDNA) used in early detection monitoring. eDNA surveillance programs seek to detect the presence of genetic material (DNA in cells sloughed off in slime,...
Developing a conservation strategy to maximize persistence of an endangered freshwater mussel species while considering management effectiveness and cost
David R. Smith, Sarah E. McRae, Tom Augspurger, Judith A. Ratcliffe, Robert B. Nichols, Chris B. Eads, Tim Savidge, Arthur E. Bogan
2015, Freshwater Science (34) 1324-1339
We used a structured decision-making process to develop conservation strategies to increase persistence of Dwarf Wedgemussel (Alasmidonta heterodon) in North Carolina, USA, while accounting for uncertainty in management effectiveness and considering costs. Alternative conservation strategies were portfolios of management actions that differed by location of management actions on the landscape....
Assessment and Mmanagement of North American horseshoe crab populations, with emphasis on a multispecies framework for Delaware Bay, U.S.A. populations: Chapter 24
Michael J. Millard, John A. Sweka, Conor P. McGowan, David R. Smith
2015, Book chapter, Changing Global Perspectives on Horseshoe Crab Biology, Conservation and Management
The horseshoe crab fishery on the US Atlantic coast represents a compelling fishery management story for many reasons, including ecological complexity, health and human safety ramifications, and socio-economic conflicts. Knowledge of stock status and assessment and monitoring capabilities for the species have increased greatly in the last 15 years and...
Horseshoe crab spawning activity in Delaware Bay, USA, after harvest reduction: A mixed-model analysis
David R. Smith, Timothy J. Robinson
2015, Estuaries and Coasts (38) 2345-2354
A Delaware Bay, USA, standardized survey of spawning horseshoe crabs, Limulus polyphemus, was carried out in 1999 − 2013 through a citizen science network. Previous trend analyses of the data were at the state (DE or NJ) or bay-wide levels. Here, an alternative mixed-model regression analysis was used to estimate...
The distribution of selected elements and minerals in soil of the conterminous United States
Laurel G. Woodruff, William F. Cannon, David B. Smith, Federico Solano
2015, Journal of Geochemical Exploration (154) 49-60
In 2007, the U.S. Geological Survey initiated a low-density (1 site per 1600 km2, 4857 sites) geochemical and mineralogical survey of soil of the conterminous United States as part of the North American Soil Geochemical Landscapes Project. Three soil samples were collected, if possible, from each site; (1) a sample from...
Developing objectives with multiple stakeholders: adaptive management of horseshoe crabs and Red Knots in the Delaware Bay
Conor P. McGowan, James E. Lyons, David Smith
2015, Environmental Management (55) 972-982
Structured decision making (SDM) is an increasingly utilized approach and set of tools for addressing complex decisions in environmental management. SDM is a value-focused thinking approach that places paramount importance on first establishing clear management objectives that reflect core values of stakeholders. To be useful for management, objectives must be...
Implementation of a framework for multi-species, multi-objective adaptive management in Delaware Bay
Conor P. McGowan, David R. Smith, James D. Nichols, James E. Lyons, John A. Sweka, Kevin Kalasz, Lawrence J. Niles, Richard Wong, Jeffrey Brust, Michelle C. Davis, Braddock Spear
2015, Biological Conservation (191) 759-769
Decision analytic approaches have been widely recommended as well suited to solving disputed and ecologically complex natural resource management problems with multiple objectives and high uncertainty. However, the difference between theory and practice is substantial, as there are very few actual resource management programs that represent formal applications of decision...
Threshold-dependent sample sizes for selenium assessment with stream fish tissue
Nathaniel P. Hitt, David R. Smith
2015, Integrated Environmental Assessment and Management (11) 143-149
Natural resource managers are developing assessments of selenium (Se) contamination in freshwater ecosystems based on fish tissue concentrations. We evaluated the effects of sample size (i.e., number of fish per site) on the probability of correctly detecting mean whole-body Se values above a range of potential management thresholds. We modeled...
Environmental DNA calibration study. Interim technical review report
K. Baerwaldt, Meredith L. Bartron, K. Schilling, Debbie Lee, Edmond Russo, Trudy Estes, Richard Fischer, Beth Fleming, Michael P. Guilfoyle, K. Jack Kilgore, Richard Lance, Edward Perkins, Martin Schultz, David Smith, Jon J. Amberg, Duane Chapman, Mark P. Gaikowski, Katy E. Klymus, Cathy A. Richter
2014, Report
Invasive aquatic nuisance species pose a major threat to aquatic ecosystems worldwide. Invasive Asian carps, including bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix) have been steadily dispersing upstream through the Mississippi, Illinois, and Des Plaines Rivers since the 1990s. To prevent further movement up the Illinois River into...
A modified procedure for mixture-model clustering of regional geochemical data
Karl J. Ellefsen, David B. Smith, John D. Horton
2014, Applied Geochemistry (51) 315-326
A modified procedure is proposed for mixture-model clustering of regional-scale geochemical data. The key modification is the robust principal component transformation of the isometric log-ratio transforms of the element concentrations. This principal component transformation and the associated dimension reduction are applied before the data are clustered. The principal advantage of...
Anthrax and the geochemistry of soils in the contiguous United States
Dale W. Griffin, Erin E. Silvestri, Charlena Y. Bowling, Timothy Boe, David B. Smith, Tonya L. Nichols
2014, Geosciences (4) 114-127
Soil geochemical data from sample sites in counties that reported occurrences of anthrax in wildlife and livestock since 2000 were evaluated against counties within the same states (MN, MT, ND, NV, OR, SD and TX) that did not report occurrences. These data identified the elements, calcium (Ca), manganese (Mn), phosphorus...
U.S. Geological Survey Science for the Wyoming Landscape Conservation Initiative: 2012 annual report
Zachary H. Bowen, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Carleton R. Bern, Laura Biewick, Gregory K. Boughton, Natasha B. Carr, Anna D. Chalfoun, Geneva W. Chong, Melanie L. Clark, Bradford C. Fedy, Katharine Foster, Steven L. Garman, Steve Germaine, Matthew G. Hethcoat, Collin G. Homer, Matthew J. Kauffman, Douglas Keinath, Natalie Latysh, Daniel J. Manier, Robert R. McDougal, Cynthia P. Melcher, Kirk A. Miller, Jessica Montag, Christopher J. Potter, Spencer Schell, Sarah L. Shafer, David B. Smith, Michael J. Sweat, Anna B. Wilson
2014, Open-File Report 2014-1093
Southwest Wyoming contains abundant energy resources, wildlife, habitat, open spaces, and outdoor recreational opportunities. Although energy exploration and development have been taking place in the region since the late 1800s, the pace of development for fossil fuels and renewable energy increased significantly in the early 2000s. This and the associated...
Geochemical and mineralogical maps for soils of the conterminous United States
David B. Smith, William F. Cannon, Laurel G. Woodruff, Federico Solano, Karl J. Ellefsen
2014, Open-File Report 2014-1082
The U.S. Geological Survey began sampling in 2007 for a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States as part of the North American Soil Geochemical Landscapes Project. The sampling protocol for the national-scale survey included, at each...
Active tensor magnetic gradiometer system final report for Project MM–1514
David V. Smith, Jeffrey D. Phillips, S. Raymond Hutton
2014, Open-File Report 2013-1228
An interactive computer simulation program, based on physical models of system sensors, platform geometry, Earth environment, and spheroidal magnetically-permeable targets, was developed to generate synthetic magnetic field data from a conceptual tensor magnetic gradiometer system equipped with an active primary field generator. The system sensors emulate the prototype tensor magnetic...
Geochemical and mineralogical data for soils of the conterminous United States
David B. Smith, William F. Cannon, Laurel G. Woodruff, Federico Solano, James E. Kilburn, David L. Fey
2013, Data Series 801
In 2007, the U.S. Geological Survey initiated a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils of the conterminous United States as part of the North American Soil Geochemical Landscapes Project. Sampling and analytical protocols were developed at a workshop in 2003, and...
Effects of surface applications of biosolids on groundwater quality and trace-element concentrations in crops near Deer Trail, Colorado, 2004-2010
Tracy J.B. Yager, James G. Crock, David B. Smith, Edward T. Furlong, Philip L. Hageman, William T. Foreman, James L. Gray, Rhiannon C. ReVello
2013, Scientific Investigations Report 2013-5065
The U.S. Geological Survey (USGS), in cooperation with Metro Wastewater Reclamation District (Metro District), studied biosolids composition and the effects of biosolids applications on groundwater quality and trace-element concentrations in crops of the Metro District properties near Deer Trail, Colorado, during 2004 through 2010. Priority parameters for each monitoring component...
History and evaluation of national-scale geochemical data sets for the United States
David B. Smith, Steven M. Smith, John D. Horton
2013, Geoscience Frontiers (4) 167-183
Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth...
