Karen R Ryberg, Ph.D. (Former Employee)
Science and Products
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 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
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...
Data Documenting the U.S. Geological Survey Peak-Flow File Data Verification Project, 2008-16 Data 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 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...
Pesticide concentration and streamflow datasets used to evaluate pesticide trends in the Nations rivers and streams, 1992-2012 Pesticide 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...
Total Phosphorus Load and Ancillary Data Related to Sources of Total Phosphorus in the Red River of the North Basin Total 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
Filter Total Items: 54
Assessing the added value of antecedent streamflow alteration information in modeling stream biological condition Assessing 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
Authors
Taylor Woods, Ken Eng, Daren M. Carlisle, Matthew J. Cashman, Michael R. Meador, Karen R. Ryberg, Kelly O. Maloney
Method for identification of reservoir regulation within U.S. Geological Survey streamgage basins in the Central United States using a decadal dam impact metric Method 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...
Authors
Mackenzie K. Marti, Karen R. Ryberg
Flood-frequency analysis in the Midwest: Addressing potential nonstationarity of annual peak-flow records Flood-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...
Authors
Mackenzie K. Marti, Karen R. Ryberg, Sara B. Levin
Simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States Simulation 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...
Authors
Jory Seth Hecht, Nancy A. Barth, Karen R. Ryberg, Angela Gregory
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 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
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...
Projecting flood frequency curves under near-term climate change Projecting 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...
Authors
Chandramauli Awasthi, Stacey A. Archfield, Karen R. Ryberg, Julie E. Kiang, A. Sankarasubramanian
Science and Products
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 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
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...
Data Documenting the U.S. Geological Survey Peak-Flow File Data Verification Project, 2008-16 Data 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 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...
Pesticide concentration and streamflow datasets used to evaluate pesticide trends in the Nations rivers and streams, 1992-2012 Pesticide 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...
Total Phosphorus Load and Ancillary Data Related to Sources of Total Phosphorus in the Red River of the North Basin Total 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
Filter Total Items: 54
Assessing the added value of antecedent streamflow alteration information in modeling stream biological condition Assessing 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
Authors
Taylor Woods, Ken Eng, Daren M. Carlisle, Matthew J. Cashman, Michael R. Meador, Karen R. Ryberg, Kelly O. Maloney
Method for identification of reservoir regulation within U.S. Geological Survey streamgage basins in the Central United States using a decadal dam impact metric Method 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...
Authors
Mackenzie K. Marti, Karen R. Ryberg
Flood-frequency analysis in the Midwest: Addressing potential nonstationarity of annual peak-flow records Flood-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...
Authors
Mackenzie K. Marti, Karen R. Ryberg, Sara B. Levin
Simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States Simulation 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...
Authors
Jory Seth Hecht, Nancy A. Barth, Karen R. Ryberg, Angela Gregory
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 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
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...
Projecting flood frequency curves under near-term climate change Projecting 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...
Authors
Chandramauli Awasthi, Stacey A. Archfield, Karen R. Ryberg, Julie E. Kiang, A. Sankarasubramanian
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government