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.
Filter Total Items: 84795
Transport of nitrogen and phosphorus in the Cedar River Basin, Iowa and Minnesota, 2000–15 Transport of nitrogen and phosphorus in the Cedar River Basin, Iowa and Minnesota, 2000–15
Nitrate concentrations in the Cedar River in Iowa and Minnesota have increased from an average of less than 1.0 milligram per liter in the early 1900s to more than 5.0 milligrams per liter in the 2000s and have resulted in periodic water-quality impairment of the river. Spatial differences and temporal changes in nitrogen and phosphorus transport in the Cedar River Basin are described...
Authors
Stephen J. Kalkhoff
Tritium deposition in precipitation in the United States, 1953–2012 Tritium deposition in precipitation in the United States, 1953–2012
Tritium is a radioactive isotope of hydrogen (half-life is equal to 12.32 years). Since it is part of the water molecule, tritium can be used to track and date groundwater and surface water when the history of tritium in precipitation and recharge is known. To facilitate that effort, tritium concentrations in precipitation were reconstructed from measurements and correlations for 10...
Authors
Robert L. Michel, Bryant C. Jurgens, Megan B. Young
Assessing and communicating the impacts of climate change on the Southern California coast Assessing and communicating the impacts of climate change on the Southern California coast
Over the course of this and the next century, the combination of rising sea levels, severe storms, and coastal erosion will threaten the sustainability of coastal communities, development, and ecosystems as we currently know them. To clearly identify coastal vulnerabilities and develop appropriate adaptation strategies for projected increased levels of coastal flooding and erosion...
Authors
Li H. Erikson, Patrick L. Barnard, Andrea C. O'Neill, Patrick Limber, Sean Vitousek, Juliette Finzi Hart, Maya Hayden, Jeanne M. Jones, Nathan J. Wood, Michael Fitzgibbon, Amy C. Foxgrover, Jessica Lovering
National Park Service and the USA National Phenology Network National Park Service and the USA National Phenology Network
Understanding the seasonal cycles of plants and animals, how they are changing, and how they can inform management, operations, and interpretation is critical to the mission of the National Park Service (NPS): to preserve unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations.
Authors
Jake Weltzin, Theresa M. Crimmins, Erin E. Posthumus, Alyssa Rosemartin
USA National Phenology Network supports decision making USA National Phenology Network supports decision making
The USA National Phenology Network is a federally-funded, nationalscale science and monitoring initiative focused on phenology as a tool to understand how plants, animals, and landscapes respond to environmental variation and change.
Authors
Jake Weltzin, Theresa M. Crimmins, Erin E. Posthumus, Alyssa Rosemartin
Phenology forecasts predict pest seasonal activity to support decision making Phenology forecasts predict pest seasonal activity to support decision making
The USA National Phenology Network (USANPN) produces and distributes daily national phenology maps – or Pheno Forecasts – indicating when key pest species may be most susceptible to management as part of a growing suite of phenology map products. The USA-NPN’s Pheno Forecast maps show when key pest species, including emerald ash borer (Agrilus planipennis), apple maggot (Rhagoletis...
Authors
Jake Weltzin, Theresa M. Crimmins, Erin Posthumous, Alyssaa Rosemartin, Katharine L. Gerst
High resolution measurement of levee subsidence related to energy infrastructure in the Sacramento-San Joaquin Delta High resolution measurement of levee subsidence related to energy infrastructure in the Sacramento-San Joaquin Delta
We assess flood overtopping potential (when flood water elevation exceeds levee elevation) to the levees surrounding the islands in the interior of California's Sacramento-San Joaquin Delta. Because critical natural gas infrastructure is susceptible to overtopping-related disruption, we focus our analysis on regions that are crossed by the network of the state's natural gas pipelines. We...
Authors
Benjamin A. Brooks, Jennifer Telling, Todd Leroy Ericksen, Craig L. Glennie, Noah Knowles, Daniel Cayan, Darren L. Hauser, Adam LeWinter
Flow hydraulics and mixing characteristics in and downstream from Brandon Road Lock, Joliet, Illinois Flow hydraulics and mixing characteristics in and downstream from Brandon Road Lock, Joliet, Illinois
The Brandon Road Lock and Dam on the Des Plaines River near Joliet, Illinois, has been identified for potential implementation of aquatic nuisance species (ANS) control measures. To provide additional information concerning the flow hydraulics and mixing characteristics of the lock and downstream approach channel, the U.S. Geological Survey performed a detailed study of the site between...
Authors
Frank L. Engel, P. Ryan Jackson, Elizabeth A. Murphy
Everglades Invasive Reptile and Amphibian Monitoring Program Everglades Invasive Reptile and Amphibian Monitoring Program
The Everglades Invasive Reptile and Amphibian Monitoring Program (EIRAMP) provides a scientific framework for integrated EDRR, outreach, and monitoring for invasive wildlife in South Florida. EIRAMP also monitors native reptiles, amphibians and mammals to assess impacts of invasive species. South Florida has more nonnative species of reptiles and amphibians than anywhere else in the...
Authors
Rebecca G. Harvey, Mike Rochford, Jennifer Ketterlin Eckles, Edward Metzger, Jennifer Nestler, Frank J. Mazzotti
Simulation of zones of groundwater contribution to wells south of the Naval Weapons Industrial Reserve Plant in Bethpage, New York Simulation of zones of groundwater contribution to wells south of the Naval Weapons Industrial Reserve Plant in Bethpage, New York
A steady-state three-dimensional groundwater-flow model that simulates present conditions was coupled with the particle-tracking program MODPATH to delineate zones of contribution to wells pumping from the Magothy aquifer near a chlorinated volatile organic compound (VOC) plume. This modeling was part of a study by the U.S. Geological Survey in cooperation with the Naval Facilities...
Authors
Paul E. Misut
Mississippi Delta: Chapter G in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010 Mississippi Delta: Chapter G in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010
The Mississippi River Delta, the tip of the longest river in North America, is located in the coastal plains of southeastern Louisiana. The study area included in the Mississippi River Delta vignette of southeastern Louisiana follows the Mississippi River southward from Port Sulphur within the modern Plaquemines-Balize Delta lobe (Figure 1). It extends eastward through Long Bay into...
Authors
Lawrence Handley, Kathryn A. Spear, Mirka Zapletal, Cindy A. Thatcher, William R. Jones, Scott A. Wilson
Understanding the effect of salinity tolerance on cyanobacteria associated with a harmful algal bloom in Lake Okeechobee, Florida Understanding the effect of salinity tolerance on cyanobacteria associated with a harmful algal bloom in Lake Okeechobee, Florida
In an effort to simulate the survival of cyanobacteria as they are transported from Lake Okeechobee to the estuarine habitats that receive waters from the lake, a bioassay encompassing a range of salinities was performed. An overall decline in cyanobacteria health in salinity treatments greater than 18 practical salinity units (psu) was indicated by loss of cell membrane integrity based...
Authors
Barry H. Rosen, Keith A. Loftin, Jennifer L. Graham, Katherine N. Stahlhut, James M. Riley, Brett D. Johnston, Sarena Senegal