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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico
Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and richness of bird groups, such as all breeding...
Authors
Glenn E. Johnson, Charles van Riper
Analysis of potential water-supply management options, 2010-60, and documentation of revisions to the model of the Irwin Basin Aquifer System, Fort Irwin National Training Center, California Analysis of potential water-supply management options, 2010-60, and documentation of revisions to the model of the Irwin Basin Aquifer System, Fort Irwin National Training Center, California
The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional, finite-difference groundwater-flow model—the U.S. Geological Survey’s MODFLOW—of the aquifer system in the basin was updated and the initial input dataset was supplemented with groundwater withdrawal data for the...
Authors
Lois M. Voronin, Jill N. Densmore, Peter Martin
Discovery and analysis of time delay sources in the USGS personal computer data collection platform (PCDCP) system Discovery and analysis of time delay sources in the USGS personal computer data collection platform (PCDCP) system
Intermagnet is an international oversight group which exists to establish a global network for geomagnetic observatories. This group establishes data standards and standard operating procedures for members and prospective members. Intermagnet has proposed a new One-Second Data Standard, for that emerging geomagnetic product. The standard specifies that all data collected must have a time...
Authors
Timothy C. White, Edward A. Sauter, Duff C. Stewart
Mapping habitat for multiple species in the Desert Southwest Mapping habitat for multiple species in the Desert Southwest
Many utility scale renewable energy projects are currently proposed across the Mojave Ecoregion. Agencies that manage biological resources throughout this region need to understand the potential impacts of these renewable energy projects and their associated infrastructure (for example, transmission corridors, substations, access roads, etc.) on species movement, genetic exchange among...
Authors
Richard D. Inman, Kenneth E. Nussear, Todd C. Esque, Amy G. Vandergast, Stacie A. Hathaway, Dustin A. Wood, Kelly R. Barr, Robert N. Fisher
Mercury in fishes from Wrangell-St. Elias National Park and Preserve, Alaska Mercury in fishes from Wrangell-St. Elias National Park and Preserve, Alaska
In this study, mercury (Hg) concentrations were examined in fishes from Wrangell-St. Elias National Park and Preserve, Alaska, the largest and one of the most remote units in the national park system. The goals of the study were to (1) examine the distribution of Hg in select lakes of Wrangell-St. Elias National Park and Preserve; (2) evaluate the differences in Hg concentrations among...
Authors
Brandon M. Kowalski, James J. Willacker, Christian E. Zimmerman, Collin A. Eagles-Smith
Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska
The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low-relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades leading to thawing of on-shore permafrost and the disappearance of sea ice at unprecedented rates. The U.S. Geological Survey’s (USGS)...
Authors
Ken D. Tape, John M. Pearce, Dennis H. Walworth, Brandt W. Meixell, Tom F. Fondell, David D. Gustine, Paul L. Flint, Jerry W. Hupp, Joel A. Schmutz, David H. Ward
A methodological toolkit for field assessments of artisanally mined alluvial diamond deposits A methodological toolkit for field assessments of artisanally mined alluvial diamond deposits
This toolkit provides a standardized checklist of critical issues relevant to artisanal mining-related field research. An integrated sociophysical geographic approach to collecting data at artisanal mine sites is outlined. The implementation and results of a multistakeholder approach to data collection, carried out in the assessment of Guinea’s artisanally mined diamond deposits, also...
Authors
Peter G. Chirico, Katherine C. Malpeli
Streamflow statistics for unregulated and regulated conditions for selected locations on the Upper Yellowstone and Bighorn Rivers, Montana and Wyoming, 1928-2002 Streamflow statistics for unregulated and regulated conditions for selected locations on the Upper Yellowstone and Bighorn Rivers, Montana and Wyoming, 1928-2002
Major floods in 1996 and 1997 intensified public debate about the effects of human activities on the Yellowstone River. In 1999, the Yellowstone River Conservation District Council was formed to address conservation issues on the river. The Yellowstone River Conservation District Council partnered with the U.S. Army Corps of Engineers to carry out a cumulative effects study on the main...
Authors
Katherine J. Chase
Baseline groundwater quality from 34 wells in Wayne County, Pennsylvania, 2011 and 2013 Baseline groundwater quality from 34 wells in Wayne County, Pennsylvania, 2011 and 2013
Wayne County, Pennsylvania, is underlain by the Marcellus Shale, which currently (2014) is being developed elsewhere in Pennsylvania for natural gas. All residents of largely rural Wayne County rely on groundwater for water supply, primarily from bedrock aquifers (shales and sandstones). This study, conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department...
Authors
Ronald A. Sloto
Calibration of a two-dimensional hydrodynamic model for parts of the Allegheny, Monongahela, and Ohio Rivers, Allegheny County, Pennsylvania Calibration of a two-dimensional hydrodynamic model for parts of the Allegheny, Monongahela, and Ohio Rivers, Allegheny County, Pennsylvania
The U.S. Geological Survey (USGS), in cooperation with the Allegheny County Sanitary Authority, developed a validated two-dimensional Resource Management Associates2 (RMA2) hydrodynamic model of parts of the Allegheny, Monongahela, and Ohio Rivers (Three Rivers) to help assess the effects of combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) on the rivers. The...
Authors
John W. Fulton, Chad R. Wagner
Ecoregions of Arizona (poster) Ecoregions of Arizona (poster)
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 ecosystems, ecoregions stratify the...
Authors
Glenn E. Griffith, James M. Omernik, Colleen Burch Johnson, Dale S. Turner
Delineation of marsh types of the Texas coast from Corpus Christi Bay to the Sabine River in 2010 Delineation of marsh types of the Texas coast from Corpus Christi Bay to the Sabine River in 2010
Coastal zone managers and researchers often require detailed information regarding emergent marsh vegetation types for modeling habitat capacities and needs of marsh-reliant wildlife (such as waterfowl and alligator). Detailed information on the extent and distribution of marsh vegetation zones throughout the Texas coast has been historically unavailable. In response, the U.S. Geological...
Authors
Nicholas M. Enwright, Stephen B. Hartley, Michael G. Brasher, Jenneke M. Visser, Michael K. Mitchell, Bart M. Ballard, Mark W. Parr, Brady R. Couvillion, Barry C. Wilson