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
Filter Total Items: 49
Stochastic model for simulating Souris River Basin precipitation, evapotranspiration, and natural streamflow
The Souris River Basin is a 61,000-square-kilometer basin in the Provinces of Saskatchewan and Manitoba and the State of North Dakota. In May and June of 2011, record-setting rains were seen in the headwater areas of the basin. Emergency spillways of major reservoirs were discharging at full or nearly full capacity, and extensive flooding was seen in numerous downstream communities. To determine t
Authors
Kelsey A. Kolars, Aldo V. Vecchia, Karen R. Ryberg
Changes in seasonality and timing of peak streamflow in snow and semi-arid climates of the north-central United States, 1910–2012
Changes in the seasonality and timing of annual peak streamflow in the north-central USA are likely because of changes in precipitation and temperature regimes. A source of long-term information about flood events across the study area is the U.S. Geological Survey peak streamflow database. However, one challenge of answering climate-related questions with this dataset is that even in snowmelt-dom
Authors
Karen R. Ryberg, F. Adnan Akyüz, Gregg J. Wiche, Wei Lin
Trends in pesticide concentrations and use for major rivers of the United States
Trends in pesticide concentrations in 38 major rivers of the United States were evaluated in relation to use trends for 11 commonly occurring pesticide compounds. Pesticides monitored in water were analyzed for trends in concentration in three overlapping periods, 1992–2001, 1997–2006, and 2001–2010 to facilitate comparisons among sites with variable sample distributions over time and among pestic
Authors
Karen R. Ryberg, Robert J. Gilliom
Changes in total phosphorus concentration in the Red River of the North Basin, 1970-2012
The Red River of the North drains much of eastern North Dakota and northwestern Minnesota and flows north into Manitoba, Canada, ultimately into Lake Winnipeg; therefore, water quality is an International concern. With increased runoff in the past few decades, phosphorus flux (the amount of phosphorus transported by the river) has increased. This is a concern, especially with respect to Lake Winni
Authors
Karen R. Ryberg, F. Adnan Akyüz, Wei Lin
Pesticides in U.S. streams and rivers: occurrence and trends during 1992-2011
During the 20 years from 1992 to 2011, pesticides were found at concentrations that exceeded aquatic-life benchmarks in many rivers and streams that drain agricultural, urban, and mixed-land use watersheds. Overall, the proportions of assessed streams with one or more pesticides that exceeded an aquatic-life benchmark were very similar between the two decades for agricultural (69% during 1992−2001
Authors
Wesley W. Stone, Robert J. Gilliom, Karen R. Ryberg
Pesticide trends in major rivers of the United States, 1992-2010
This report is part of a series of pesticide trend assessments led by the National Water-Quality Assessment Program of the U.S. Geological Survey. This assessment focuses on major rivers of various sizes throughout the United States that have large watersheds with a range of land uses, changes in pesticide use, changes in management practices, and natural influences typical of the regions being dr
Authors
Karen R. Ryberg, Aldo V. Vecchia, Robert J. Gilliom, Jeffrey D. Martin
Impact of climate variability on runoff in the north-central United States
Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) t
Authors
Karen R. Ryberg, Wei Lin, Aldo V. Vecchia
Monitoring and understanding changes in heat waves, cold waves, floods, and droughts in the United States: State of knowledge
Weather and climate extremes have been varying and changing on many different time scales. In recent decades, heat waves have generally become more frequent across the United States, while cold waves have been decreasing. While this is in keeping with expectations in a warming climate, it turns out that decadal variations in the number of U.S. heat and cold waves do not correlate well with the obs
Authors
Thomas C. Peterson, Richard R. Heim, Robert M. Hirsch, Dale P. Kaiser, Harold Brooks, Noah S. Diffenbaugh, Randall M. Dole, Jason P. Giovannettone, Kristen Guirguis, Thomas R. Karl, Richard W. Katz, Kenneth E. Kunkel, Dennis P. Lettenmaier, Gregory J. McCabe, Christopher J. Paciorek, Karen R. Ryberg, BS Silva K Wolter, Siegfried Schubert, Viviane B. S. Silva, Brooke C. Stewart, Aldo V. Vecchia, Gabriele Villarini, Russell S. Vose, John Walsh, Michael Wehner, David Wolock, Klaus Wolter, Connie A. Woodhouse, Donald Wuebbles
seawaveQ: an R package providing 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
The seawaveQ R package fits a parametric regression model (seawaveQ) to pesticide concentration data from streamwater samples to assess variability and trends. The model incorporates the strong seasonality and high degree of censoring common in pesticide data and users can incorporate numerous ancillary variables, such as streamflow anomalies. The model is fitted to pesticide data using maximum li
Authors
Karen R. Ryberg, Aldo V. Vecchia
waterData--An R package for retrieval, analysis, and anomaly calculation of daily hydrologic time series data, version 1.0
Hydrologic time series data and associated anomalies (multiple components of the original time series representing variability at longer-term and shorter-term time scales) are useful for modeling trends in hydrologic variables, such as streamflow, and for modeling water-quality constituents. An R package, called waterData, has been developed for importing daily hydrologic time series data from U.S
Authors
Karen R. Ryberg, Aldo V. Vecchia
Has the magnitude of floods across the USA changed with global CO2 levels?
Statistical relationships between annual floods at 200 long-term (85–127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record are explored. The streamgauge locations are limited to those with little or no regulation or urban development. The coterminous US is divided into four large regions and stationary bootstrapping is us
Authors
Robert M. Hirsch, Karen R. Ryberg
Has the magnitude of floods across the USA changed with global CO 2 levels?
Statistical relationships between annual floods at 200 long-term (85-127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record are explored. The streamgauge locations are limited to those with little or no regulation or urban development. The coterminous US is divided into four large regions and stationary bootstrapping is us
Authors
R.M. Hirsch, K.R. Ryberg
Science and Products
- Publications
Filter Total Items: 49
Stochastic model for simulating Souris River Basin precipitation, evapotranspiration, and natural streamflow
The Souris River Basin is a 61,000-square-kilometer basin in the Provinces of Saskatchewan and Manitoba and the State of North Dakota. In May and June of 2011, record-setting rains were seen in the headwater areas of the basin. Emergency spillways of major reservoirs were discharging at full or nearly full capacity, and extensive flooding was seen in numerous downstream communities. To determine tAuthorsKelsey A. Kolars, Aldo V. Vecchia, Karen R. RybergChanges in seasonality and timing of peak streamflow in snow and semi-arid climates of the north-central United States, 1910–2012
Changes in the seasonality and timing of annual peak streamflow in the north-central USA are likely because of changes in precipitation and temperature regimes. A source of long-term information about flood events across the study area is the U.S. Geological Survey peak streamflow database. However, one challenge of answering climate-related questions with this dataset is that even in snowmelt-domAuthorsKaren R. Ryberg, F. Adnan Akyüz, Gregg J. Wiche, Wei LinTrends in pesticide concentrations and use for major rivers of the United States
Trends in pesticide concentrations in 38 major rivers of the United States were evaluated in relation to use trends for 11 commonly occurring pesticide compounds. Pesticides monitored in water were analyzed for trends in concentration in three overlapping periods, 1992–2001, 1997–2006, and 2001–2010 to facilitate comparisons among sites with variable sample distributions over time and among pesticAuthorsKaren R. Ryberg, Robert J. GilliomChanges in total phosphorus concentration in the Red River of the North Basin, 1970-2012
The Red River of the North drains much of eastern North Dakota and northwestern Minnesota and flows north into Manitoba, Canada, ultimately into Lake Winnipeg; therefore, water quality is an International concern. With increased runoff in the past few decades, phosphorus flux (the amount of phosphorus transported by the river) has increased. This is a concern, especially with respect to Lake WinniAuthorsKaren R. Ryberg, F. Adnan Akyüz, Wei LinPesticides in U.S. streams and rivers: occurrence and trends during 1992-2011
During the 20 years from 1992 to 2011, pesticides were found at concentrations that exceeded aquatic-life benchmarks in many rivers and streams that drain agricultural, urban, and mixed-land use watersheds. Overall, the proportions of assessed streams with one or more pesticides that exceeded an aquatic-life benchmark were very similar between the two decades for agricultural (69% during 1992−2001AuthorsWesley W. Stone, Robert J. Gilliom, Karen R. RybergPesticide trends in major rivers of the United States, 1992-2010
This report is part of a series of pesticide trend assessments led by the National Water-Quality Assessment Program of the U.S. Geological Survey. This assessment focuses on major rivers of various sizes throughout the United States that have large watersheds with a range of land uses, changes in pesticide use, changes in management practices, and natural influences typical of the regions being drAuthorsKaren R. Ryberg, Aldo V. Vecchia, Robert J. Gilliom, Jeffrey D. MartinImpact of climate variability on runoff in the north-central United States
Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) tAuthorsKaren R. Ryberg, Wei Lin, Aldo V. VecchiaMonitoring and understanding changes in heat waves, cold waves, floods, and droughts in the United States: State of knowledge
Weather and climate extremes have been varying and changing on many different time scales. In recent decades, heat waves have generally become more frequent across the United States, while cold waves have been decreasing. While this is in keeping with expectations in a warming climate, it turns out that decadal variations in the number of U.S. heat and cold waves do not correlate well with the obsAuthorsThomas C. Peterson, Richard R. Heim, Robert M. Hirsch, Dale P. Kaiser, Harold Brooks, Noah S. Diffenbaugh, Randall M. Dole, Jason P. Giovannettone, Kristen Guirguis, Thomas R. Karl, Richard W. Katz, Kenneth E. Kunkel, Dennis P. Lettenmaier, Gregory J. McCabe, Christopher J. Paciorek, Karen R. Ryberg, BS Silva K Wolter, Siegfried Schubert, Viviane B. S. Silva, Brooke C. Stewart, Aldo V. Vecchia, Gabriele Villarini, Russell S. Vose, John Walsh, Michael Wehner, David Wolock, Klaus Wolter, Connie A. Woodhouse, Donald WuebblesseawaveQ: an R package providing 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
The seawaveQ R package fits a parametric regression model (seawaveQ) to pesticide concentration data from streamwater samples to assess variability and trends. The model incorporates the strong seasonality and high degree of censoring common in pesticide data and users can incorporate numerous ancillary variables, such as streamflow anomalies. The model is fitted to pesticide data using maximum liAuthorsKaren R. Ryberg, Aldo V. VecchiawaterData--An R package for retrieval, analysis, and anomaly calculation of daily hydrologic time series data, version 1.0
Hydrologic time series data and associated anomalies (multiple components of the original time series representing variability at longer-term and shorter-term time scales) are useful for modeling trends in hydrologic variables, such as streamflow, and for modeling water-quality constituents. An R package, called waterData, has been developed for importing daily hydrologic time series data from U.SAuthorsKaren R. Ryberg, Aldo V. VecchiaHas the magnitude of floods across the USA changed with global CO2 levels?
Statistical relationships between annual floods at 200 long-term (85–127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record are explored. The streamgauge locations are limited to those with little or no regulation or urban development. The coterminous US is divided into four large regions and stationary bootstrapping is usAuthorsRobert M. Hirsch, Karen R. RybergHas the magnitude of floods across the USA changed with global CO 2 levels?
Statistical relationships between annual floods at 200 long-term (85-127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record are explored. The streamgauge locations are limited to those with little or no regulation or urban development. The coterminous US is divided into four large regions and stationary bootstrapping is usAuthorsR.M. Hirsch, K.R. Ryberg - Science
- Data
No Result Found
- Multimedia
No results found.
- News