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Jennifer Murphy

Jenny is a hydrologist with the USGS, Central Midwest Water Science Center. Much of her work focuses on characterizing and understanding water-quality trends in the Nation's streams and rivers. Jenny also leads a team of scientists working to develop a proxy for harmful algal blooms in rivers.

Jenny has played an important role in characterizing water-quality trends with the Weighted Regressions on Time, Season and Discharge (WRTDS) model at >1,000 sites across the country using an extensive multi-agency dataset. Jenny's additional trends work includes looking at nitrate in the Mississippi River Basin, sediment in the lowermost Mississippi and Atchafalaya Rivers, and water quality in streams and rivers in the Delaware River Basin. Additionally, she has worked on projects ranging from the evaluation of best management practices in small agricultural drainages, to characterizing and understanding ecological flows, estimating water use at thermoelectric powerplants, and harmonizing multisource data.  Her current interests are in trend studies, causal attribution of these trends, and exploring the influence of streamflow on water quality.

CURRENT & PAST PROJECTS

  • Co-lead of multisource surface water-quality trends task as part of the IWAAs Delaware River Basin Regional Pilot
  • NAWQA Surface Water Status and Trends team (Causal Analysis team lead)
  • Evaluating agricultural best management practices in northwestern MS
  • Ecological flows in the Cumberland and Tennessee River Basins
  • Water-quality trends in the Mississippi River Basin
  • Water use at thermoelectric powerplants
  • Water quality in the lowermost Mississippi and Atchafalaya Rivers

 

Professional Experience

  • 2020-Present, Hydrologist, USGS, Central Midwest Water Science Center, DeKalb, Illinois

  • 2010-2020, Hydrologist, USGS,  Lower Mississippi-Gulf Water Science Center, Nashville, TN

  • 2007-2009, Project Geologist, ECS Limited, Nashville, TN

  • Summer 2007, Field Geologist, US Forest Service, Lewis and Clark National Forest, Great Falls, MT

  • 2006-2007, Research Assistant, USGS, Eastern Mineral Resources, Reston, VA

Education and Certifications

  • M.S., Earth and Environmental Science, Vanderbilt University, Nashville, Tennessee, 2011

  • B.A., Geology, Lawrence University, Appleton, Wisconsin, 2006

Science and Products

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gage house next to body of water lined with fall colored trees

Regional Water Availability Assessment: Delaware River Basin

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Delaware River Basin, the USGS will conduct a focused assessment of increasing freshwater salinity and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.
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Water Resources Mission Area
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Regional Water Availability Assessment: Delaware River Basin

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Delaware River Basin, the USGS will conduct a focused assessment of increasing freshwater salinity and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.
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USGS Hydrologist Collects a Water-Quality Sample at Henry, Illinois

Harmful Algal Bloom Research and Monitoring - CMWSC

The Central Midwest Water Science Center (CMWSC) includes three states: Illinois, Iowa, and Missouri. The water science center is responsible for providing information on discharge, water quality, water-use, and groundwater data. The Harmful Algal Bloom (HABs) team is currently researching ways to better predict, analyze, and study HABs.
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Central Midwest Water Science Center
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Harmful Algal Bloom Research and Monitoring - CMWSC

The Central Midwest Water Science Center (CMWSC) includes three states: Illinois, Iowa, and Missouri. The water science center is responsible for providing information on discharge, water quality, water-use, and groundwater data. The Harmful Algal Bloom (HABs) team is currently researching ways to better predict, analyze, and study HABs.
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USGS employee collecting water quality sample at USGS gage 09359020 Animas River below Silverton, CO.

Water-Quality Trends

Is water quality getting better or worse? Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.
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Water Resources Mission Area, National Water Quality Program
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Water-Quality Trends

Is water quality getting better or worse? Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.
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Stream in Tennessee forrest

Environmental Flow Research in the Tennessee River Basin

The objective of this project is to improve understanding of how alteration of streamflow characteristics affects the ecological health of rivers and streams in Tennessee. Initial efforts are aimed at identifying critical streamflow characteristics and providing a set of statistical tools and analytical approaches for the prediction of these characteristics. Application of these tools will enhance...
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Lower Mississippi-Gulf Water Science Center
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Environmental Flow Research in the Tennessee River Basin

The objective of this project is to improve understanding of how alteration of streamflow characteristics affects the ecological health of rivers and streams in Tennessee. Initial efforts are aimed at identifying critical streamflow characteristics and providing a set of statistical tools and analytical approaches for the prediction of these characteristics. Application of these tools will enhance...
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Filter Total Items: 19

Modeled transport components of daily chlorophyll-a in the Illinois River, 2018 through 2020 (version 1.1, April 2024)

TThis data release contains approximately three years of modeled chlorophyll-a—a proxy for planktonic algal biomass—transport through a 394-km portion of the Illinois River. Defined by four distinct reaches, model estimates include daily water balance, velocities, and algal biomass separated into its components of net growth, net loss, transported from upstream, and input from tributaries. First
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Water Resources Mission Area

Data to support Leveraging machine learning to automate regression model evaluations for large multi-site water-quality trend studies

This data release contains one dataset and one model archive in support of the journal article, "Leveraging machine learning to automate regression model evaluations for large multi-site water-quality trend studies," by Jennifer C. Murphy and Jeffrey G. Chanat. The model archive contains scripts (run in R) to reproduce the four machine learning models (logistic regression, linear and quadratic dis
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Central Midwest Water Science Center

Data supporting a spatiotemporal trend analysis of specific conductivity, streamflow, and landscape attributes of selected sub-basins within the Delaware River watershed, 1980 to 2018

This data release makes available three data tables supporting a spatiotemporal analysis of riverine conductivity and streamflow trends within the Delaware River Basin. The listed datasets include baseflow and total flow time series for selected gaged basins, watershed attributes, water quality information and trend analysis results.
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Maryland-Delaware-D.C. Water Science Center

A national harmonized dataset of discrete chlorophyll from lakes and streams (2005-2022)

This data release contains a 17-year record (2005-2022) of discrete chlorophyll data from inland waters, collected from across the nation and territories. These data are from discrete samples (collected in the field and analyzed in the laboratory) from plankton (suspended algae) and periphyton (benthic algae) from lakes, streams, rivers, reservoirs, canals, and other sites. These data are gathered
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Ohio-Kentucky-Indiana Water Science Center

Compilation of State-Level Freshwater Harmful Algal Bloom Recreational and Drinking Water Guidelines for the Conterminous United States as of 2022

This data release contains a national compilation of state-level qualitative and quantitative guidance for a variety of environmental indicators that are used to identify the presence of a harmful algal bloom (HAB) in freshwater ecosystems. These include qualitative guidelines based on visual or olfactory signals, as well as quantitative guidelines based on cyanotoxin concentrations, algal biomass
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Central Midwest Water Science Center

Harmonized discrete and continuous water quality data in support of modeling harmful algal blooms in the Illinois River Basin, 2005 - 2020

Harmful algal blooms (HABs) are overgrowths of algae or cyanobacteria in water and can be harmful to humans and animals directly via toxin exposure or indirectly via changes in water quality and related impacts to ecosystems services, drinking water characteristics, and recreation. While HABs occur frequently throughout the United States, the driving conditions behind them are not well understood,
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Water Resources Mission Area

Datasets of Suspended Sediment Concentration and Percent Fines (1973–2021), Sampling Information (1973–2021), and Daily Streamflow (1928–2021) for Sites in the Lower Mississippi and Atchafalaya Rivers to Support Analyses of Sediment Tran

Datasets of suspended sediment concentration and percent fines, sampling information, and daily streamflow data were compiled and harmonized for 16 sites to better understand sediment transport and delivery in the Lower Mississippi and Atchafalaya Rivers. The compiled data were harmonized by removing unnecessary columns, screening data for laboratory or sampling issues, creating consistent entries
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Central Midwest Water Science Center

Water-quality and streamflow datasets used in Weighted Regressions on Time, Discharge, and Season (WRTDS) models to determine trends in the Nation’s rivers and streams, 1972-2017

In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project. One of the major goals of the NAWQA project was to determine how river water quality has changed over time. To support that goal, long-term consistent and comparable monitoring has been conducted by the USGS on streams and r
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Central Midwest Water Science Center

Data to Incorporate Water Quality Analysis into Navigation Assessments as Demonstrated in the Mississippi River Basin

This data release includes estimates of annual and monthly mean concentrations and fluxes for nitrate plus nitrite, orthophosphate and suspended sediment for nine sites in the Mississippi River Basin (MRB) produced using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model (Hirsch and De Cicco, 2015). It also includes a model archive (R scripts and readMe file) used to retrieve an
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Central Midwest Water Science Center

Water-quality trends for rivers and streams in the Delaware River Basin using Weighted Regressions on Time, Discharge, and Season (WRTDS) models, Seasonal Kendall Trend (SKT) tests, and multisource data, Water Year 1978-2018

This data release provides water-quality trends for rivers and streams in the Delaware River Basin determined using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model and the Seasonal Kendall Trend (SKT) test. Sixteen water-quality parameters were assessed, including nutrients (ammonia, nitrate, filtered orthophosphate, total nitrogen, total phosphorus, and unfiltered orthophosp
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Central Midwest Water Science Center

Multi-source surface-water-quality data and U.S. Geological Survey streamgage match for the Delaware River Basin

Jointly managed by multiple states and the federal government, there are many ongoing efforts to characterize and understand water quality in the Delaware River Basin (DRB). Many State, Federal and non-profit organizations have collected surface-water-quality samples across the DRB for decades and many of these data are available through the National Water Quality Monitoring Council's Water Qualit
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Water Resources Mission Area

Hydrologic event-based water-quality and streamflow data for three oxbow tributaries in northwestern Mississippi, 2007-2016

For about 10 years, the U.S. Geological Survey (USGS) has monitored water quality and streamflow in three agricultural drainage ditches in an effort to evaluate the influence of best management practices on water quality. These ditches are small tributaries to oxbow lakes located in the Mississippi Alluvial Plain of northwestern Mississippi--two sites (LWSR and LWT2) drain to Lake Washington and o
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Lower Mississippi-Gulf Water Science Center
Filter Total Items: 29

River control points for algal productivity revealed by transport analysis

Measurement of planktonic chlorophyll-a—a proxy for algal biomass—in rivers may represent local production or algae transported from upstream, confounding understanding of algal bloom development in flowing waters. We modeled 3 years of chlorophyll-a transport through a 394-km portion of the Illinois River and found that although algal biomass is longitudinally widespread, most net production occu
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Noah Schmadel, Judson Harvey, Jay Choi, Sarah M. Stackpoole, Jennifer L. Graham, Jennifer C. Murphy
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Water Resources Mission Area, New York Water Science Center, Central Midwest Water Science Center

Leveraging machine learning to automate regression model evaluations for large multi-site water-quality trend studies

Large multi-site trend studies provide an opportunity to evaluate progress of waterbodies towards water-quality goals across broad geographic areas. Such studies often aggregate the results of site-specific models and thus contend with evaluating each model for appropriate fit and statistical assumptions. We explored the use of four traditional machine learning models (logistic regression, linear
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Jennifer C. Murphy, Jeffrey G. Chanat
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Water Resources Mission Area, Virginia and West Virginia Water Science Center, Central Midwest Water Science Center

Differing field methods and site conditions lead to varying bias in suspended sediment concentrations in the Lower Mississippi and Atchafalaya Rivers

At sites that have been sampled for decades, changes in field and laboratory methods happen over time as instrumentation and protocols improve. Here, we compare the influence of depth- and point-integrated sampling on total, fine (< 0.0625 mm), and coarse (≥ 0.0625 mm) suspended sediment (SS) concentrations in the Lower Mississippi and Atchafalaya Rivers. Using historical field method information,
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Jennifer C. Murphy, Lindsey Ayn Schafer, Scott Mize
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Central Midwest Water Science Center, Lower Mississippi-Gulf Water Science Center, Mississippi River

The "H," "A," and "B" of a HAB: A definitional framework

The use of the phrase “harmful algal bloom” and the acronym HAB originated in the marine science world, and referred to blooms also known as red tides, which can kill fish and sea life. The organisms that make up marine HABs generally do not thrive in lakes. In freshwater, HABs are most often associated with blooms of toxin-producing cyanobacteria. The term HAB started to be used broadly in the ea
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Rebecca Michelle Gorney, Jennifer L. Graham, Jennifer C. Murphy
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Water Resources Mission Area, New York Water Science Center, Central Midwest Water Science Center

River water quality in the Delaware River Basin—Concentrations and trends through 2018

IntroductionThe Delaware River Basin provides drinking water to 13.3 million people and supports endangered species, provides recreational opportunities, and is an essential resource to regional industries. The efforts of Federal and State governments have substantially improved overall water quality in the basin, which had been severely degraded prior to the mid-20th century. Recent trend analyse
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Megan E. Shoda, Emily G Gain, Jennifer C. Murphy
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Central Midwest Water Science Center, Lower Mississippi-Gulf Water Science Center, Maryland-Delaware-D.C. Water Science Center, New Jersey Water Science Center, New York Water Science Center, Ohio-Kentucky-Indiana Water Science Center, Pennsylvania Water Science Center

Water-quality trends in the Delaware River Basin calculated using multisource data and two methods for trend periods ending in 2018

Many organizations in the Delaware River Basin (DRB) monitor surface-water quality for regulatory, scientific, and decision-making purposes. In support of these purposes, over 260,000 water-quality records provided by 8 different organizations were compiled, screened, and used to generate water-quality trends in the DRB. These trends, for periods of record that end in 2018, were generated for 124
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Megan E. Shoda, Jennifer C. Murphy
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Ohio-Kentucky-Indiana Water Science Center, Pennsylvania Water Science Center

Water quality of sand and gravel aquifers in McHenry County, Illinois, 2020 and comparisons to conditions in 2010

McHenry County, Illinois, obtains most of its drinking water from shallow sand and gravel aquifers (groundwater). To evaluate this groundwater resource, the U.S. Geological Survey, in cooperation with McHenry County, Illinois, collected water-quality samples from 41 of 42 monitoring wells in the McHenry County Groundwater Monitoring Network and 4 monitoring wells from the U.S. Geological Survey Na
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Amy M. Gahala, Lance R. Gruhn, Jennifer C. Murphy, Lisa A. Matson
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Central Midwest Water Science Center

Spatial patterns and seasonal timing of increasing riverine specific conductance from 1998 to 2018 suggest legacy contamination in the Delaware River Basin

Increasing salinization of freshwater threatens water supplies that support a range of human and ecological uses. The latest assessments of Delaware River Basin (DRB) surface-water-quality changes indicate widespread salinization has occurred in recent decades, which may lead to meaningful degradation in water quality. To better understand how and when salinity transport occurs and implications fo
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Christine Rumsey, John C. Hammond, Jennifer C. Murphy, Megan E. Shoda, Alex M. Soroka
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Water Resources Mission Area, Utah Water Science Center, Central Midwest Water Science Center

Incorporating water quality analysis into navigation assessments as demonstrated in the Mississippi River Basin

A description of historical and ambient water quality conditions is often required as part of navigational studies. This paper describes a series of tools developed by the USGS that can aid navigation managers in developing water quality assessments. The tools use R, a statistical software program, and provide methods to retrieve historical streamflow and water quality data, summarize observations
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Barbara Kleiss, Jennifer C. Murphy, Casey M. Mayne, Jake P. Allgeier, Amanda B. Edmondson, Katrina C. Ginsberg, Keaton E. Jones, Timothy J. Lauth, Emily L. Moe, Julie W. Murphy, Mead Allison
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Central Midwest Water Science Center

Landscape drivers of dynamic change in water quality of US rivers

Water security is a top concern for social well-being and dramatic changes in the availability of freshwater have occurred as a result of human uses and landscape management. Elevated nutrient loading and perturbations to major ion composition have resulted from human activities and have degraded freshwater resources. This study addresses the emerging nature of stream water quality in the 21st ce
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Edward G. Stets, Lori A. Sprague, Gretchen P. Oelsner, Henry M. Johnson, Jennifer C. Murphy, Karen R. Ryberg, Aldo V. Vecchia, Robert E. Zuellig, James A. Falcone, Melissa L. Riskin
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Water Resources Mission Area, New Jersey Water Science Center

A historical look at changing water quality in the Delaware River basin

In 2019 the U.S. Geological Survey (USGS) launched a pilot regional Integrated Water Availability Assessment (IWAA) in the Delaware River Basin (fig. 1). IWAA is intended to explore, test, and refine systems and processes for assessing water availability for human and ecological uses and understanding their underlying controls. Water quality plays an important role in supporting ecological health
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Jennifer C. Murphy, Megan E. Shoda
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Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center, Pennsylvania Water Science Center

Pooling resources across organizations — Multisource water-quality data for the Delaware River Basin

The U.S. Geological Survey (USGS) recently launched a pilot Integrated Water Availability Assessment (IWAA) in the Delaware River Basin to explore, test, and refine systems and processes for assessing water availability for human and ecological uses based on water monitoring data. Water-quality monitoring provides citizens, managers, and scientists with the information needed to evaluate the healt
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Jennifer C. Murphy, Megan E. Shoda
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Water Resources Mission Area, New Jersey Water Science Center, Pennsylvania Water Science Center

Non-USGS Publications**

Murphy, J.C., G.M. Hornberger, and R.G. Liddle, 2014, Concentration–discharge relationships in the coal mined region of the New River basin and Indian Fork sub-basin, Tennessee, USA. Hydrological Processes 28: 718-728.
Debra Perrone, Jennifer Murphy, and George M. Hornberger (2011), Gaining Perspective on the Water−Energy Nexus at the Community Scale. Environ. Sci. Technol., 2011, 45 (10), pp 4228–4234
DOI: 10.1021/es103230n.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Tracking Water Quality of the Nation's Streams and Rivers

An online graphical data tool provides annual summaries of nutrient and sediment concentrations and loads and streamflow information for 106 sites monitored as part of the USGS National Water-Quality Network for Streams and Rivers.

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Water Resources Mission Area, National Water Quality Program, Gulf of Mexico

EGRET

An R-package for the analysis of long-term changes in water quality and streamflow, including the water-quality method Weighted Regressions on Time, Discharge, and Season (WRTDS).
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Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center
Concentrations of suspended sediment decreasing in many US streams and rivers

Concentrations of suspended sediment decreasing in many US streams and rivers

A new USGS study reports that landscape management actions across the U.S. aimed at reducing concentrations of suspended sediment in streams and...

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