Reports
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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Trends in recent historical and projected climate data for the Colorado River Basin and potential effects on groundwater availability Trends in recent historical and projected climate data for the Colorado River Basin and potential effects on groundwater availability
Understanding recent historical and projected trends in precipitation and temperature in the Colorado River Basin, and estimating what the projected changes in these climate parameters may mean for groundwater resources in the region, is important for water managers and policymakers to sustainably manage water resources in the basin. Historical (1896–2019) precipitation and temperature...
Authors
Fred D. Tillman, Subhrendu Gangopadhyay, Tom Pruitt
Alkalic-type epithermal gold deposit model Alkalic-type epithermal gold deposit model
This report summarizes the primary characteristics of alkalic-type epithermal gold (Au) deposits and provides an updated descriptive model. These deposits, primarily of Mesozoic to Neogene age, are among the largest epithermal gold deposits in the world. Considered a subset of low-sulfidation epithermal deposits, they are spatially and genetically linked to small stocks or clusters of...
Authors
Karen D. Kelley, Paul G. Spry, Virginia T. McLemore, David L. Fey, Eric D. Anderson
History of U.S. Geological Survey scientific peer review and approval, 1879–2019 History of U.S. Geological Survey scientific peer review and approval, 1879–2019
The U.S. Geological Survey (USGS), a bureau within the U.S. Department of the Interior, has valued and used a scientific peer review and approval process since its creation in 1879. Bureau approval, formerly called Director’s approval, has been described in several USGS documents since 1900, and peer review has been codified in policy since 1959. Peer review of USGS manuscripts is...
Authors
Keith Kirk, Carolyn Reid, Sandra Cooper
Literature reviewed estimates of riparian consumptive water use in the drylands of Northeast Arizona, USA Literature reviewed estimates of riparian consumptive water use in the drylands of Northeast Arizona, USA
This report provides the best estimates of riparian area evapotranspiration (ET) on the rivers and streams of the Navajo Nation by (1) quantifying the natural riparian vegetation water use within the Little Colorado River watershed using a literature search for comparable riparian ET estimates, and (2) in conjunction with the given area of stream-side plant cover on the Navajo Nation...
Authors
Pamela L. Nagler
Shorebird research at the U.S. Geological Survey Alaska Science Center Shorebird research at the U.S. Geological Survey Alaska Science Center
Shorebirds—which include sandpipers, plovers, and oystercatchers—are perhaps best known by their presence on sandy beaches, running along the water’s edge while they probe for food. But they are probably less recognized for their impressive long-distance migrations. Millions of individuals travel from across the globe to breed throughout Alaska each spring, making these birds a familiar...
Authors
Daniel R. Ruthrauff, T. Lee Tibbitts, John Pearce
Soil moisture product validation good practices protocol, version 1.0 Soil moisture product validation good practices protocol, version 1.0
The Global Climate Observing System (GCOS) included soil moisture in the list of Essential Climate Variables (ECVs) to express its important role in Earth’s water, energy and carbon cycle. Soil moisture has a major impact on agriculture, land surface hydrology, weather, and climate forecasting. This document is a community-based effort to provide recommendations on good practices for the
Authors
Carsten Montzka, Michael H. Cosh, Bagher Bayat, Ahmad Al Bitar, Aaron Berg, Rajat Bindlish, Heye Reemt Bogena, John D. Bolton, Francois Cabot, Todd Caldwell, Steven Chan, Andreas Colliander, Wade Crow, Narendra Das, Gabrielle De Lannoy, Wouter Dorigo, Steven R. Evett, Alexander Gruber, Sebastian Hahn, Thomas Jagdhuber, Scott F. Jones, Yann Kerr, Seung-bum Kim, Christian Koyama, Mehmed Kurum, Ernesto Lopez-Baeza, Francesco Mattia, Kaighin A. McColl, Susanne Mecklenburg, Binayak Mohanty, Peggy O’Neill, Dani Or, Thierry Pellarin, George P. Petropoulos, Maria Piles, Rolf H. Reichle, Nemesio Rodriguez-Fernandez, Christoph Rudiger, Tracy Scanlon, Robert C. Schwartz, Daniel Spengler, Prashant K. Srivastava, Swati Suman, Robin van der Schalie, Wolfgang Wagner, Urs Wegmuller, Jean-Pierre Wigneron, Fernando Camacho, Jaime Nickeson
Investigation of suitable habitat for the endangered plant Ptilimnium nodosum (Rose) Mathias (harperella) using remote sensing and field analysis—Documentation of methods and results Investigation of suitable habitat for the endangered plant Ptilimnium nodosum (Rose) Mathias (harperella) using remote sensing and field analysis—Documentation of methods and results
Ptilimnium nodosum (Rose) Mathias (harperella) is an endangered plant species found in Maryland, Virginia, and West Virginia, as well as in other locations throughout the southeastern United States. The narrow range of habitat characteristics for areas in which harperella has been found makes locating potential occurrence sites difficult and attempts at reintroduction of the plant...
Authors
Jessica D. DeWitt, Kelsey L. O’Pry, Pete G. Chirico, John A. Young
Technical overview of the U.S. Geological Survey Earth Mapping Resources Initiative (Earth MRI) Technical overview of the U.S. Geological Survey Earth Mapping Resources Initiative (Earth MRI)
The Earth Mapping Resources Initiative (Earth MRI) was developed by the U.S. Geological Survey in response to a Federal directive calling on various Federal agencies to address potential vulnerabilities in the Nation’s supply of critical mineral resources. The primary purpose of this initiative is to identify potentially mineralized areas containing critical minerals by gathering new...
Authors
Warren C. Day
Effects of a crude-oil recovery remediation system operated 1999–2003 on groundwater plumes and unsaturated-zone vapor concentrations at a crude-oil spill site near Bemidji, Minnesota Effects of a crude-oil recovery remediation system operated 1999–2003 on groundwater plumes and unsaturated-zone vapor concentrations at a crude-oil spill site near Bemidji, Minnesota
A crude-oil spill occurred in 1979 when a pipeline burst near Bemidji, Minnesota. More than 70 percent of the 1.7 million liters of spilled crude oil was removed shortly thereafter. In response to a requirement by the State regulatory agency to remove the remaining crude to a sheen in all wells, in 1998, the pipeline company installed a dual-pump recovery system at the site. This...
Authors
Geoffrey N. Delin, William N. Herkelrath, Jared J. Trost
Spatial and temporal patterns in streamflow, water chemistry, and aquatic macroinvertebrates of selected streams in Fairfax County, Virginia, 2007–18 Spatial and temporal patterns in streamflow, water chemistry, and aquatic macroinvertebrates of selected streams in Fairfax County, Virginia, 2007–18
Urbanization substantially alters the landscape in ways that can impact stream hydrology, water chemistry, and the health of aquatic communities. Stormwater best management practices (BMPs) are the primary tools used to mitigate the effects of urban stressors such as increased runoff, decreased baseflow, and increased nutrient and sediment transport. To date, Fairfax County Virginia’s...
Authors
Aaron J. Porter, James S. Webber, Jonathan W. Witt, John D. Jastram
Regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas Regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas
The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, assessed statistical relations between hydraulic properties of streams at approximate bankfull conditions for different ecological regions (ecoregions) in Texas. Data from more than 103,000 records of measured discharge and ancillary hydraulic properties were assembled from summaries of discharge...
Authors
William H. Asquith, John D. Gordon, David S. Wallace
Southern (California) sea otter population status and trends at San Nicolas Island, 2017–2020 Southern (California) sea otter population status and trends at San Nicolas Island, 2017–2020
The southern sea otter (Enhydra lutris nereis) population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. Monitoring efforts have varied in frequency and type across years. In 2017, the U.S. Navy and the U.S. Fish and Wildlife Service initiated a sea otter monitoring and research plan to...
Authors
Julie L. Yee, Joseph A. Tomoleoni, Michael C. Kenner, Jessica Fujii, Gena B. Bentall, M. Tim Tinker, Brian B. Hatfield