Skip to main content
U.S. flag

An official website of the United States government

Publications

Read publications and other informational products to learn more about USGS science occurring in the Mississippi Basin.

Filter Total Items: 5584

Scientist’s guide to developing explanatory statistical models using causal analysis principles Scientist’s guide to developing explanatory statistical models using causal analysis principles

Recent discussions of model selection and multimodel inference highlight a general challenge for researchers, which is how to clearly convey the explanatory content of a hypothesized model or set of competing models. The advice from statisticians for scientists employing multimodel inference is to develop a well‐thought‐out set of candidate models for comparison, though precise...
Authors
James B. Grace, Kathryn Irvine

Simulation of groundwater flow and chloride transport in the “1,500-foot” sand, “2,400-foot” sand, and “2,800-foot” sand of the Baton Rouge area, Louisiana Simulation of groundwater flow and chloride transport in the “1,500-foot” sand, “2,400-foot” sand, and “2,800-foot” sand of the Baton Rouge area, Louisiana

Groundwater withdrawals since the 1940s have lowered water levels, altered groundwater-flow directions, and caused saltwater to intrude within some freshwater-containing sands of the fluvial-deltaic Southern Hills regional aquifer system beneath Baton Rouge, Louisiana. New interpretations of stratigraphic correlations amongst geophysical well logs were utilized to revise a hydrogeologic...
Authors
Charles E. Heywood, Maxwell A. Lindaman, John K. Lovelace

An experimental evaluation of the feasibility of inferring concentrations of a visible tracer dye from remotely sensed data in turbid rivers An experimental evaluation of the feasibility of inferring concentrations of a visible tracer dye from remotely sensed data in turbid rivers

The movement of contaminants and biota within river channels is influenced by the flow field via various processes of dispersion. Understanding and modeling of these processes thus can facilitate applications ranging from the prediction of travel times for spills of toxic materials to the simulation of larval drift for endangered species of fish. A common means of examining dispersion in...
Authors
Carl J. Legleiter, Paul Manley, Susannah O. Erwin, Edward A. Bulliner

Plot Locator: An app for locating plots in the field Plot Locator: An app for locating plots in the field

PREMISE: One of the challenges in field biology is locating previously sampled plots. The Plot Locator app was developed to assist field biologists with plot identification and location, with or without GPS or online connectivity. METHODS AND RESULTS: The Plot Locator Android app helps users locate field plots by creating a searchable database that stores study area information, such as...
Authors
Jere Boudell, Beth A. Middleton

Using maintenance records from a long-term sensor monitoring network to evaluate the relationship between maintenance schedule and data quality Using maintenance records from a long-term sensor monitoring network to evaluate the relationship between maintenance schedule and data quality

Sensor-based environmental monitoring networks are beginning to provide the large-scale, long-term data required to address important fundamental and applied questions in ecology. However, the data quality from deployed sensors can be difficult and costly to ensure. In this study, we use maintenance records from the 12-year history of Louisiana’s Coastwide Reference Monitoring System...
Authors
Donald R. Schoolmaster, Sarai Piazza

Understanding tidal marsh trajectories: Evaluation of multiple indicators of marsh persistence Understanding tidal marsh trajectories: Evaluation of multiple indicators of marsh persistence

Robust assessments of ecosystem stability are critical for informing conservation and management decisions. Tidal marsh ecosystems provide vital services, yet are globally threatened by anthropogenic alterations to physical and biological processes. A variety of monitoring and modeling approaches have been undertaken to determine which tidal marshes are likely to persist into the future...
Authors
Kerstin Wasson, Neil K. Ganju, Zafer Defne, Charlie Endris, Tracy Elsey-Quirk, Karen M. Thorne, Chase M. Freeman, Glenn R. Guntenspergen, Daniel J. Nowacki, Kenneth B. Raposa

Simulation of post-hurricane impact on invasive species with biological control management Simulation of post-hurricane impact on invasive species with biological control management

Understanding the effects of hurricanes and other large storms on ecological communities and the post-event recovery in these communities can guide management and ecosystem restoration. This is particularly important for communities impacted by invasive species, as the hurricane may affect control efforts. Here we consider the effect of a hurricane on tree communities in southern Florida...
Authors
Linhao Xu, Marya Claire Zdechlik, Melissa C. Smith, Min B. Rayamajhi, Don DeAngelis, Bo Zhang

Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts

The glacial kettle ponds in the Hyannis Ponds Wildlife Management Area in Barnstable, Massachusetts, support a community of rare and endangered plants. The ponds are hydraulically connected to the unconfined aquifer that underlies Cape Cod. The plants are adapted to the rise and fall of water levels in the ponds as the water table fluctuates in response to seasonal and year-to-year...
Authors
Denis R. LeBlanc, Timothy D. McCobb, Jeffrey R. Barbaro

Influence of turbulence and in-stream structures on the transport and survival of grass carp eggs and larvae at various developmental stages Influence of turbulence and in-stream structures on the transport and survival of grass carp eggs and larvae at various developmental stages

Understanding the response of grass carp to flow and turbulence regimes during early life stages is fundamental to monitoring and controlling their spread. A comprehensive set of hydrodynamic experiments was conducted with live grass carp eggs and larvae, to better understand their drifting and swimming patterns with 3 different in-stream obstructions: (1) a gravel bump, (2) a single...
Authors
Andres F. Prada, Amy E. George, Benjamin H. Stahlschmidt, P. Ryan Jackson, Duane Chapman, Rafael O. Tinoco

Phosphorus runoff risk assessment in karstic regions of the U.S. Phosphorus runoff risk assessment in karstic regions of the U.S.

The Phosphorus (P) Index risk assessment tool has been widely adopted across the U.S. to identify and rank site vulnerability to P runoff as part of the Natural Resources Conservation Service (NRCS) nutrient management planning (NMP) process. However, limited success has been achieved in addressing the risk of P loss by subsurface flow pathways, despite its relative importance in certain...
Authors
Andrew N. Sharpley, Phillip D. Hays, Michael B. Daniels, Karl W. VanDevender

Time scales of arsenic variability and the role of high-frequency monitoring at three water-supply wells in New Hampshire, USA Time scales of arsenic variability and the role of high-frequency monitoring at three water-supply wells in New Hampshire, USA

Groundwater geochemistry, redox process classification, high-frequency physicochemical and hydrologic measurements, and climate data were analyzed to identify controls on arsenic (As) concentration changes. Groundwater was monitored in two public-supply wells (one glacial aquifer and one bedrock aquifer), and one bedrock-aquifer domestic well in New Hampshire, USA, from 2014 to 2018 to...
Authors
James R. Degnan, Joseph P. Levitt, Melinda L. Erickson, Bryant C. Jurgens, Bruce D. Lindsey, Joseph D. Ayotte

Traveling to thermal refuges during stressful temperatures leads to foraging constraints in a central-place forager Traveling to thermal refuges during stressful temperatures leads to foraging constraints in a central-place forager

Central-place foragers can be constrained by the distance between habitats. When an organism relies on a central place for thermal refuge, the distance to food resources can potentially constrain foraging behavior. We investigated the effect of distance between thermal refuges and forage patches of the cold-intolerant marine mammal, the Florida manatee (Trichechus manatus latirostris)...
Authors
Catherine G. Haase, Robert J. Fletcher, Daniel H. Slone, James P. Reid, Susan M. Butler
Was this page helpful?