USGS scientist Karen Ryberg was interviewed during the conference about drought
conditions in the Dakotas.
Karen R Ryberg, Ph.D.
Research Statistician for the Dakota Water Science Center
Expertise/Projects/Research Interests
- Statistical analysis of hydrologic data, including parametric and nonparametric trend analysis and cluster analysis
- Trend analysis for pesticide concentrations in surface water
- Research related to the impact of climate variability on surface water
- Data mining including automated data retrieval and analysis, outlier detection, and data cleaning
- Machine learning
- Graphical presentation of scientific data
- R - Open Source Statistical Software
- waterData package - Retrieval, analysis, and anomaly calculation of daily hydrologic time series data
- seawaveQ package - A model and utilities for analyzing trends in chemical concentrations in streams with a seasonal wave (seawave) and adjustment for streamflow (Q) and other ancillary variables
- Associate Editor, Hydrological Sciences Journal
- Course Coordinator and member of team teaching Statistical Methods for Environmental Data Analysis at USGS National Training Center
Publications
Ryberg, K.R., 2021, The role of the U.S. Geological Survey in monitoring North Dakota’s environmental conditions: North Dakota Climate Bulletin, v. 15, no. 1, p. 11–14, https://www.ndsu.edu/ndsco/climatesummaries/quarterlyclimatebulletin/.
Helsel, D.R., Hirsch, R.M., Ryberg, K.R., Archfield, S.A., and Gilroy, E.J., 2020, Statistical methods in water resources: U.S. Geological Survey Techniques and Methods, book 4, chapter A3, 458 p., https://doi.org/10.3133/tm4a3. [Supersedes USGS Techniques of Water-Resources Investigat
Education and Certifications
Doctorate of Philosophy, Environmental and Conservation Sciences - Environmental Science Track, 2015 North Dakota State University, Fargo, North Dakota
Dissertation: The impact of climate variability
Master of Science, Statistics, 2006, Colorado State University, Fort Collins, Colorado
Masters Project: Water-quality trend analysis for the Devils Lake Basin, North Dakota, January 1965 through Sept
Associate of Applied Science, Computer Support Specialist, 2003 Bismarck State College, Bismarck, North Dakota
Bachelor of Arts, Mathematics, 1995 Luther College, Decorah, Iowa
Mathematics for Machine Learning Specialization Certificate— Imperial College London on Coursera, 2020
Facilitator Training—Learning to Lead Reflective Conversations, an educational program of Humanities North Dakota and Bismarck State College, Bismarck, ND., 2018
Specialization Certificate in Executive Data Science— Johns Hopkins University on Coursera, 2018
Graduate Certificate, Data Mining and Applications, 2008, Stanford University, Stanford, California
Management, 1996, University of Mary, Bismarck, North Dakota
Science and Products
Introduction and methods of analysis for peak streamflow trends and their relation to changes in climate in Illinois, Iowa, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wisconsin
Assessing the added value of antecedent streamflow alteration information in modeling stream biological condition
Method for identification of reservoir regulation within U.S. Geological Survey streamgage basins in the Central United States using a decadal dam impact metric
Flood-frequency analysis in the Midwest: Addressing potential nonstationarity of annual peak-flow records
Simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States
Attribution of monotonic trends and change points in peak streamflow across the conterminous United States using a multiple working hypotheses framework, 1941–2015 and 1966–2015
Projecting flood frequency curves under near-term climate change
Assessment of streamflow trends in the eastern Dakotas, water years 1960–2019
Historical and paleoflood analyses for probabilistic flood-hazard assessments—Approaches and review guidelines
Climate extremes as drivers of surface-water-quality trends in the United States
The role of the U.S. Geological Survey in monitoring North Dakota’s environmental conditions
Statistical methods in water resources
Flood-Frequency Analysis in the Midwest: Addressing Potential Nonstationary Annual Peak-Flow Records
Peak Streamflow Data, Climate Data, and Results from Investigating Hydroclimatic Trends and Climate Change Effects on Peak Streamflow in the Central United States, 1921–2020
Data from Assessing the added value of antecedent streamflow alteration in modelling stream condition
Data for simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States
Attributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
Peak-streamflow trends and change-points and basin characteristics for 2,683 U.S. Geological Survey streamgages in the conterminous U.S.
Daily streamflow datasets used to analyze trends in streamflow at sites also analyzed for trends in water quality and ecological condition in the Nation's rivers and streams
Data Documenting the U.S. Geological Survey Peak-Flow File Data Verification Project, 2008-16
Ancillary Data Related to Nutrients in the Chesapeake BayData Supporting Structural Equation Modeling of Nutrient Loads
Pesticide concentration and streamflow datasets used to evaluate pesticide trends in the Nations rivers and streams, 1992-2012
Total Phosphorus Load and Ancillary Data Related to Sources of Total Phosphorus in the Red River of the North Basin
USGS scientist Karen Ryberg was interviewed during the conference about drought
conditions in the Dakotas.
Jim Lake drawdown channel, looking south. Photograph from Humpback Road. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake drawdown channel, looking south. Photograph from Humpback Road. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake drawdown channel looking north. Photograph taken from 17th Street SE between Pingree, North Dakota, and State Highway 20. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake drawdown channel looking north. Photograph taken from 17th Street SE between Pingree, North Dakota, and State Highway 20. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Mud Lake Channel from Arrowwood Lake to Jim Lake, looking toward Arrowwood Lake. Photograph taken from 11th Street SE between Edmunds, North Dakota, and State Highway 9. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Mud Lake Channel from Arrowwood Lake to Jim Lake, looking toward Arrowwood Lake. Photograph taken from 11th Street SE between Edmunds, North Dakota, and State Highway 9. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
James River by Arrowwood National Wildlife Refuge. The picture was taken from the scenic view site to the North and above headquarters.
James River by Arrowwood National Wildlife Refuge. The picture was taken from the scenic view site to the North and above headquarters.
Science and Products
- Publications
Filter Total Items: 49
Introduction and methods of analysis for peak streamflow trends and their relation to changes in climate in Illinois, Iowa, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wisconsin
Flood-frequency analysis, also called peak-flow frequency or flood-flow frequency analysis, is essential to water resources management applications including critical structure design and floodplain mapping. Federal guidelines for doing flood-frequency analyses are presented in a U.S. Geological Survey Techniques and Methods Report known as Bulletin 17C. A basic assumption within Bulletin 17C is tAuthorsKaren R. Ryberg, Thomas M. Over, Sara B. Levin, David C. Heimann, Nancy A. Barth, Mackenzie K. Marti, Padraic S. O'Shea, Christopher A. Sanocki, Tara J. Williams-Sether, Harper N. Wavra, T. Roy Sando, Steven K. Sando, Milan S. LiuAssessing the added value of antecedent streamflow alteration information in modeling stream biological condition
In stream systems, disentangling relationships between biology and flow and subsequent prediction of these relationships to unsampled streams is a common objective of large-scale ecological modeling. Often, streamflow metrics are derived from aggregating continuous streamflow records available at a subset of stream gages into long-term flow regime descriptors. Despite demonstrated value, shortcomiAuthorsTaylor E Woods, Ken Eng, Daren Carlisle, Matt J. Cashman, Michael Meador, Karen R. Ryberg, Kelly O. MaloneyMethod for identification of reservoir regulation within U.S. Geological Survey streamgage basins in the Central United States using a decadal dam impact metric
Researchers routinely study streamflow data to understand the effects of natural climate variability and anthropogenic climate change, and to develop methods for estimating streamflow at ungaged locations. These studies require streamflow data that are not modified or largely altered by other anthropogenic activities, such as reservoirs or diversions. This report discusses a method for identifyingAuthorsMackenzie K. Marti, Karen R. RybergFlood-frequency analysis in the Midwest: Addressing potential nonstationarity of annual peak-flow records
Flood-frequency analysis is essential in numerous water-resource management applications, including critical structure design and flood-plain mapping. A basic assumption within Bulletin 17C [1], the standardized guidelines for conducting flood-frequency analysis, is that basins without major hydrologic alterations, such as regulation or urbanization, exhibit stationary statistical properties of thAuthorsMackenzie K. Marti, Karen R. Ryberg, Sara B. LevinSimulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States
While nonstationary flood frequency analysis (NSFFA) methods have proliferated, few studies have rigorously compared them for modeling changes in both the central tendency and variability of annual peak-flow series, also known as the annual maximum series (AMS), in hydrologically diverse areas. Through Monte Carlo experiments, we appraise five methods for updating estimates of 10- and 100-year floAuthorsJory Seth Hecht, Nancy A. Barth, Karen R. Ryberg, Angela GregoryAttribution of monotonic trends and change points in peak streamflow across the conterminous United States using a multiple working hypotheses framework, 1941–2015 and 1966–2015
The U.S. Geological Survey has a long history of leading flood-frequency analysis studies. These studies play a critical role in the assessment of risk, protection of lives, and planning and design of flood protection infrastructure. Standard flood-frequency analysis is based on the assumption of stationarity—that is, that the distribution of floods at a given site varies around a particular meanProjecting flood frequency curves under near-term climate change
Flood-frequency curves, critical for water infrastructure design, are typically developed based on a stationary climate assumption. However, climate changes are expected to violate this assumption. Here, we propose a new, climate-informed methodology for estimating flood-frequency curves under non-stationary future climate conditions. The methodology develops an asynchronous, semiparametric local-AuthorsChandramauli Awasthi, Stacey A. Archfield, Karen R. Ryberg, Julie E. Kiang, A. SankarasubramanianAssessment of streamflow trends in the eastern Dakotas, water years 1960–2019
Hydrologic extremes, whether periods of drought or flooding, are occurring more frequently with greater severity and can have substantial economic impacts. Along with flooding, the timing and volume of streamflow also is changing across the United States. The focus of this report is to characterize a unique trend in mean annual streamflow occurring in eastern North and South Dakota, hereafter refeAuthorsParker A. Norton, Gregory C. Delzer, Joshua F. Valder, Wyatt S. Tatge, Karen R. RybergHistorical and paleoflood analyses for probabilistic flood-hazard assessments—Approaches and review guidelines
Paleoflood studies are an effective means of providing specific information on the recurrence and magnitude of rare and large floods. Such information can be combined with systematic flood measurements to better assess the frequency of large floods. Paleoflood data also provide valuable information about the linkages among climate, land use, flood-hazard assessments, and channel morphology. This dAuthorsTessa M. Harden, Karen R. Ryberg, Jim E. O'Connor, Jonathan M. Friedman, Julie E. KiangClimate extremes as drivers of surface-water-quality trends in the United States
Surface-water quality can change in response to climate perturbations, such as changes in the frequency of heavy precipitation or droughts, through direct effects, such as dilution and concentration, and through physical processes, such as bank scour. Water quality might also change through indirect mechanisms, such as changing water demand or changes in runoff interaction with organic matter on tAuthorsKaren R. Ryberg, Jeffrey G. ChanatThe role of the U.S. Geological Survey in monitoring North Dakota’s environmental conditions
No abstract available.AuthorsKaren R. RybergStatistical methods in water resources
This text began as a collection of class notes for a course on applied statistical methods for hydrologists taught at the U.S. Geological Survey (USGS) National Training Center. Course material was formalized and organized into a textbook, first published in 1992 by Elsevier as part of their Studies in Environmental Science series. In 2002, the work was made available online as a USGS report.The tAuthorsDennis R. Helsel, Robert M. Hirsch, Karen R. Ryberg, Stacey A. Archfield, Edward J. Gilroy - Science
Flood-Frequency Analysis in the Midwest: Addressing Potential Nonstationary Annual Peak-Flow Records
Period of Project: 2021 - Study Area: Midwest Cooperating Agency: Transportation Pooled Fund - Data
Peak Streamflow Data, Climate Data, and Results from Investigating Hydroclimatic Trends and Climate Change Effects on Peak Streamflow in the Central United States, 1921–2020
Peak-flow frequency analysis is crucial in various water-resources management applications, including floodplain management and critical structure design. Federal guidelines for peak-flow frequency analyses, provided in Bulletin 17C, assume that the statistical properties of the hydrologic processes driving variability in peak flows do not change over time and so the frequency distribution of annuData from Assessing the added value of antecedent streamflow alteration in modelling stream condition
The dataset contains long-term and short-term summaries of streamflow alteration and measures of biological condition (fish multi-metric index). Streamflow alteration metrics include the magnitude, duration, frequency, and seasonality of high and low flow streamflow. Biological condition was estimated from the National Rivers and Streams Assessment and National Water Quality Assessment fish sampliData for simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States
This dataset contains files used in this Monte Carlo simulation study comparing the performance of five statistical models for adjusting design floods for current conditions at sites with known trends. These files include (i) the observed annual peak-flow series in the conterminous US used to inform ranges of known moments and trends used in the simulation experiment, (ii) the 3,000 combinations oAttributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
The U.S. Geological Survey Dakota Water Science Center, in cooperation with the Federal Highway Administration, analyzed annual peak-flow data to determine if trends are present and provide attribution of trends where possible. Work for the national trend attributions for nonstationary annual peak-flow records was broken into seven regions that are loosely based off of two-digit hydrologic unit waPeak-streamflow trends and change-points and basin characteristics for 2,683 U.S. Geological Survey streamgages in the conterminous U.S.
This data release contains drainage basin characteristics and peak-streamflow trend and change-point results for 2,683 U.S. Geological Survey (USGS) streamgages in the conterminous U.S. Data include streamgage identification number, name, drainage area, latitude, longitude, percent urban land use, dam storage, streamgage classification, record completeness status, lag-1 autocorrelation, trend slopDaily streamflow datasets used to analyze trends in streamflow at sites also analyzed for trends in water quality and ecological condition in the Nation's rivers and streams
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 of the National Water-Quality Program. One of the major goals of the NAWQA project is to determine how water-quality conditions change over time. To support that goal, long-term consistent and comparable monitoring has been cData Documenting the U.S. Geological Survey Peak-Flow File Data Verification Project, 2008-16
These data provide a public summary of the changes made to the U.S. Geological Survey peak-flow file since formal Nation-wide checking began in 2008. Coverage includes peak-flow sites in the United States and territories.Ancillary Data Related to Nutrients in the Chesapeake BayData Supporting Structural Equation Modeling of Nutrient Loads
This data release provides total nitrogen (TN) and total phosphorus (TP) annual loads for sites within the Chesapeake Bay, as well as ancillary data that describe potential nutrient sources and processes. The purpose of the study for which these data were developed is to test causal hypotheses, using structural equation models, related to the drivers of TN and TP load in the Chesapeake Bay over thPesticide concentration and streamflow datasets used to evaluate pesticide trends in the Nations rivers and streams, 1992-2012
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 of the National Water-Quality Program. One of the major goals of the NAWQA project is to determine how water-quality conditions change over time. To support that goal, long-term consistent and comparable monitoring has been cTotal Phosphorus Load and Ancillary Data Related to Sources of Total Phosphorus in the Red River of the North Basin
The Red River of the North (Red River) transports phosphorus from North Dakota, Minnesota, and South Dakota, to Manitoba, Canada, and eventually into Lake Winnipeg. Phosphorus load (or flux) is the amount of total phosphorus (TP) transported by the Red River. The effect of TP load on water quality is a concern, especially with respect to downstream eutrophication issues in Lake Winnipeg, Manitob - Multimedia
Interview at 2018 South Dakota Hydrology ConferenceInterview at 2018 South Dakota Hydrology Conference
USGS scientist Karen Ryberg was interviewed during the conference about drought
conditions in the Dakotas.USGS scientist Karen Ryberg was interviewed during the conference about drought
conditions in the Dakotas.Jim Lake Drawdown Channel Arrowwood National Wildlife RefugeJim Lake Drawdown Channel Arrowwood National Wildlife RefugeJim Lake drawdown channel, looking south. Photograph from Humpback Road. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake drawdown channel, looking south. Photograph from Humpback Road. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake Drawdown Channel Arrowwood National Wildlife RefugeJim Lake Drawdown Channel Arrowwood National Wildlife RefugeJim Lake drawdown channel looking north. Photograph taken from 17th Street SE between Pingree, North Dakota, and State Highway 20. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Jim Lake drawdown channel looking north. Photograph taken from 17th Street SE between Pingree, North Dakota, and State Highway 20. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Mud Lake Channel Arrowwood National Wildlife RefugeMud Lake Channel Arrowwood National Wildlife RefugeMud Lake Channel from Arrowwood Lake to Jim Lake, looking toward Arrowwood Lake. Photograph taken from 11th Street SE between Edmunds, North Dakota, and State Highway 9. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
Mud Lake Channel from Arrowwood Lake to Jim Lake, looking toward Arrowwood Lake. Photograph taken from 11th Street SE between Edmunds, North Dakota, and State Highway 9. The downstream Jamestown Reservoir was filled in 1965 and backed water onto the Arrowwood National Wildlife Refuge, preventing ideal management in most years.
The James RiverJames River by Arrowwood National Wildlife Refuge. The picture was taken from the scenic view site to the North and above headquarters.
James River by Arrowwood National Wildlife Refuge. The picture was taken from the scenic view site to the North and above headquarters.
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