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Science Quality and Integrity
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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Ungulate migrations of the Western United States, volume 4
Broadly distributed across the Western United States, ungulates (hooved mammals) play an important role in ecosystem function by affecting vegetation communities and forming the prey base for large carnivores. Additionally, ungulates provide economic benefits to regional communities through tourism and hunting and hold cultural significance for many Tribal communities. Many ungulates migrate seaso
Authors
Matthew Kauffman, Blake Lowrey, Chloe Beaupre, Scott Bergen, Stefanie Bergh, Kevin Blecha, Samantha Bundick, Hunter Burkett, James W. Cain III, Peyton Carl, David Casady, Corey Class, Alyson Courtemanch, Michelle Cowardin, Jennifer Diamond, Katie Dugger, Orrin Duvuvuei, Joanna R. Ennis, Michelle Flenner, Jessica Fort, Gary Fralick, Ian Freeman, Jeff Gagnon, David Garcelon, Kyle Garrison, Emily Gelzer, Evan Greenspan, Valerie Hinojoza-Rood, Pat Hnilicka, Andy Holland, Brian Hudgens, Bart Kroger, Art Lawson, Cody McKee, Jennifer L. McKee, Jerod Merkle, Tony W. Mong, Haley Nelson, Brendan Oates, Marie-Pier Poulin, Craig Reddell, Robert Ritson, Hall Sawyer, Cody Schroeder, Jessie Shapiro, Scott Sprague, Erik Steiner, Alethea Steingisser, Sam Stephens, Blair Stringham, Patrick Ryan Swazo-Hinds, Nicole Tatman, Cody F. Wallace, Don Whittaker, Benjamin Wise, Heiko U. Wittmer, Erin Wood
2021 Volcanic activity in Alaska and the Commonwealth of the Northern Mariana Islands—Summary of events and response of the Alaska Volcano Observatory
In 2021, the Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at 15 volcanic centers in Alaska and the Commonwealth of the Northern Mariana Islands. Eruptive activity in Alaska consisted of repeated small, ash-producing, phreatomagmatic explosions from Mount Young on Semisopochnoi Island; an explosion at Gr
Authors
Tim R. Orr, Hannah R. Dietterich, David Fee, Társilo Girona, Ronni Grapenthin, Matthew M. Haney, Matthew W. Loewen, John J. Lyons, John A. Power, Hans F. Schwaiger, David J. Schneider, Darren Tan, Liam Toney, Valerie K. Wasser, Christopher F. Waythomas
2020 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at nine volcanic centers in Alaska in 2020. The most notable volcanic activity in 2020 was an eruption of Shishaldin Volcano, which produced lava flows, lahars, and ash. Mount Cleveland had one small ash-producing eruption in June but was quiet thereafter
Authors
Tim R. Orr, Cheryl Cameron, Hannah R. Dietterich, Matthew W. Loewen, Taryn Lopez, John J. Lyons, Jenny Nakai, John A. Power, Cheryl Searcy, Gabrielle Tepp, Christopher F. Waythomas
Using structured decision making to assess management alternatives to inform the 2024 update of the Minnesota Invasive Carp Action Plan
This report summarizes the results of a structured decision making process started by the Minnesota Department of Natural Resources to develop and evaluate various invasive carp management strategies to inform a 2024 update of the Minnesota Invasive Carp Action Plan. The Minnesota Department of Natural Resources invited State, Federal, Tribal, and nongovernmental organization partners to participa
Authors
Max Post van der Burg, Michael E. Colvin
Groundwater and surface-water interactions in the He‘eia watershed, O‘ahu, Hawai‘i—Insights from analysis of historical data and numerical groundwater-model simulations
He‘eia and ‘Ioleka‘a Streams in the He‘eia watershed on O‘ahu, Hawai‘i, receive substantial discharge from dike-impounded groundwater. Previous studies indicated that groundwater withdrawals from the watershed affect streamflow. Resource managers and users seek information that can be used to balance the needs of competing uses of groundwater and streamflow in the watershed.In this study, analyses
Authors
Scot K. Izuka, Heidi L. Kāne, Kolja Rotzoll
Groundwater hydrology, groundwater and surface-water interactions, aquifer testing, and groundwater-flow simulations for the Fountain Creek alluvial aquifer, near Colorado Springs, Colorado, 2018–20
From 2018 through 2020, the U.S. Geological Survey, in cooperation with the Air Force Civil Engineering Center, conducted an integrated study of the Fountain Creek alluvial aquifer located near Colorado Springs, Colorado. The objective of the study was to characterize hydrologic conditions for the alluvial aquifer pertinent to the potential for transport of solutes. Specific goals of this report w
Authors
Connor P. Newman, Cory A. Russell, Zachary D. Kisfalusi, Suzanne Paschke
Estimation and comparison of 1-percent annual exceedance probability flood flows at Federal Emergency Management Agency flood insurance study flow locations across Pennsylvania
Flood-flow estimates were computed at over 5,000 Federal Emergency Management Agency (FEMA) flood insurance study (FIS) flow locations across Pennsylvania for the 1-percent annual exceedance probability flood event (1-percent AEP). Depending on a point of interest’s proximity to a streamgage, weighting techniques may be applied to obtain flood-flow estimates for ungaged flow locations using observ
Authors
Mitchell R. Weaver, Marla H. Stuckey, James E. Colgin, Mark A. Roland
Bathymetric and velocimetric surveys at highway bridges crossing the Missouri River between Kansas City and St. Louis, Missouri, May 19–26, 2021
Bathymetric and velocimetric data were collected by the U.S. Geological Survey, in cooperation with the Missouri Department of Transportation, near nine bridges at eight highway crossings of the Missouri River between Kansas City and St. Louis, Missouri, from May 19 to 26, 2021. A multibeam echosounder mapping system was used to obtain channel-bed elevations for river reaches about 1,640 to 1,840
Authors
Richard J. Huizinga
Land-use and land-cover change in the Lower Rio Grande Ecoregions, Texas, 2001–2011
Urban growth and other land-use changes were examined in the Lower Rio Grande Valley and Alluvial Floodplain ecoregions in Texas, along the U.S.-Mexico border. The analysis focused on understanding the types and causes of land change as well as the recovery of natural land-cover types between years 2001 and 2011. The purpose was to develop improved capabilities for understanding land change dynami
Authors
Mark A. Drummond, Michael P. Stier, Jamie L. McBeth
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—2018 high resolution mapping surveys
Executive Summary This study examined the abundance and distribution of nutrients and phytoplankton in the tidal aquatic environments of the Sacramento–San Joaquin Delta (Delta) and Suisun Bay, comprising three spatial surveys conducted in May, July, and October of 2018 that used continuous underway high frequency sampling and measurements onboard a high-speed boat to characterize spatial variatio
Authors
Brian A. Bergamaschi, Tamara E. C. Kraus, Bryan D. Downing, Elizabeth B. Stumpner, Katy O'Donnell, Jeffrey A. Hansen, Jeniffer Soto Perez, Emily T. Richardson, Angela M. Hansen, Alan Gelber
Triangle Area Water Supply Monitoring Project, North Carolina—Overview of hydrologic and water-quality monitoring activities and data quality assurance
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have participated in a cooperative effort, known as the Triangle Area Water Supply Monitoring Project, to track water-quality and quantity
Authors
J.C. Diaz, R.M. Fanelli
Phytoplankton, taste-and-odor compounds, and cyanotoxin occurrence in four water-supply reservoirs in the Triangle area of North Carolina, April–October 2014
Prior to 2014, local utilities and State agencies monitored for cyanotoxins and taste-and-odor (T&O) compounds and reported occasional detections in three water-supply reservoirs in Wake County, North Carolina. Comparable data for cyanotoxins and T&O compounds were lacking for other water-supply reservoirs in the Triangle area of North Carolina. This report assesses whether cyanotoxins and T&O com
Authors
Celeste A. Journey, Anna M. McKee, Jessica C. Diaz