Human alteration of waterways has impacted the minimum and maximum streamflows in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries. Increasingly, state and local decision-makers and federal agencies are turning their attention to the restoration of flows as part of a holistic approach to restoring water quality and habitat and to protecting and replenishing living coastal and marine resources and the livelihoods that depend on them.
In 2017, the USGS and US EPA began collaborating on a comprehensive, large-scale, state-of-the-science foundational project to provide vital information on the timing and delivery of freshwater to streams, bays, estuaries, and wetlands of the Gulf Coast. The information generated through this project will provide local, state, and federal officials the ability to evaluate how streamflow withdrawals and reservoir operations throughout the watershed may alter streamflow metrics and freshwater inputs to the estuary.
EPA and USGS Proposal to the Gulf Coast Ecosystem Restoration Council--
Streamflow Alteration Assessments to Support Bay and Estuary Restoration in Gulf States
Human alteration of waterways has impacted the minimum and maximum streamflows in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries.
Increasingly, state and local decision-makers and federal agencies are turning their attention to the restoration of flows as part of a holistic approach to restoring water quality and habitat and to protecting and replenishing living coastal and marine resources and the livelihoods that depend on them.
The U.S. Geological Survey and the U.S. Environmental Protection Agency propose to collaborate on a comprehensive, large-scale, state-of-the-science foundational project to provide vital information on the timing and delivery of freshwater to streams, bays, estuaries, and wetlands of the Gulf Coast. Ecologically relevant streamflow metrics and measures of streamflow alteration will be developed for streams throughout the Gulf states and made available via an online mapping tool. An assessment of trends in streamflow delivery to Gulf coast estuaries will improve the understanding of potential drivers of change in estuarine health. A streamflow accounting model will be developed for one large watershed in the Gulf States to evaluate and understand how streamflow alteration at locations in the upper basins may impact the magnitude, timing, duration, and frequency of freshwater flows to the Gulf. This model will provide local, state, and federal officials the ability to evaluate how streamflow withdrawals and reservoir operations throughout the watershed may alter streamflow metrics and freshwater inputs to the estuary.
Key questions to be addressed include:
Gulf-wide Assessment
Which streams in the Gulf States have the largest amounts of streamflow alteration? What are the gaps in stream flow data for assessing streamflow alteration in Gulf States?
Are shifts in magnitude, timing, duration, and frequency of freshwater delivery to estuaries distinguishable from natural signals?
Large Watershed Assessment
How far downstream from alteration points do substantial shifts in streamflow metrics occur?
How sensitive are estuary freshwater inputs to upstream streamflow alterations? Is there a threshold of fresh water alteration below which no signal is detected in an estuary?
Below are publications associated with this project.
An analysis of streamflow trends in the southern and southeastern US from 1950-2015
An interactive data visualization framework for exploring geospatial environmental datasets and model predictions
The use of support vectors from support vector machines for hydrometeorologic monitoring network analyses
Copula theory as a generalized framework for flow-duration curve-based streamflow estimates in ungaged and partially gaged catchments
Prediction and inference of flow-duration curves using multi-output neural networks
Putting flow-ecology relationships into practice: A decision-support system to assess fish community response to water-management scenarios
Model calibration criteria for estimating ecological flow characteristics
Accelerating advances in continental domain hydrologic modeling
Evaluation of statistical and rainfall-runoff models for predicting historical daily streamflow time series in the Des Moines and Iowa River watersheds
Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States
Modelling ecological flow regime: an example from the Tennessee and Cumberland River basins
Invertebrate response to changes in streamflow hydraulics in two urban areas in the United States
Below are partners associated with this project.
- Overview
Human alteration of waterways has impacted the minimum and maximum streamflows in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries. Increasingly, state and local decision-makers and federal agencies are turning their attention to the restoration of flows as part of a holistic approach to restoring water quality and habitat and to protecting and replenishing living coastal and marine resources and the livelihoods that depend on them.
In 2017, the USGS and US EPA began collaborating on a comprehensive, large-scale, state-of-the-science foundational project to provide vital information on the timing and delivery of freshwater to streams, bays, estuaries, and wetlands of the Gulf Coast. The information generated through this project will provide local, state, and federal officials the ability to evaluate how streamflow withdrawals and reservoir operations throughout the watershed may alter streamflow metrics and freshwater inputs to the estuary.
EPA and USGS Proposal to the Gulf Coast Ecosystem Restoration Council--
Streamflow Alteration Assessments to Support Bay and Estuary Restoration in Gulf States
Human alteration of waterways has impacted the minimum and maximum streamflows in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries.
Increasingly, state and local decision-makers and federal agencies are turning their attention to the restoration of flows as part of a holistic approach to restoring water quality and habitat and to protecting and replenishing living coastal and marine resources and the livelihoods that depend on them.
The U.S. Geological Survey and the U.S. Environmental Protection Agency propose to collaborate on a comprehensive, large-scale, state-of-the-science foundational project to provide vital information on the timing and delivery of freshwater to streams, bays, estuaries, and wetlands of the Gulf Coast. Ecologically relevant streamflow metrics and measures of streamflow alteration will be developed for streams throughout the Gulf states and made available via an online mapping tool. An assessment of trends in streamflow delivery to Gulf coast estuaries will improve the understanding of potential drivers of change in estuarine health. A streamflow accounting model will be developed for one large watershed in the Gulf States to evaluate and understand how streamflow alteration at locations in the upper basins may impact the magnitude, timing, duration, and frequency of freshwater flows to the Gulf. This model will provide local, state, and federal officials the ability to evaluate how streamflow withdrawals and reservoir operations throughout the watershed may alter streamflow metrics and freshwater inputs to the estuary.
Key questions to be addressed include:
Gulf-wide Assessment
Which streams in the Gulf States have the largest amounts of streamflow alteration? What are the gaps in stream flow data for assessing streamflow alteration in Gulf States?
Are shifts in magnitude, timing, duration, and frequency of freshwater delivery to estuaries distinguishable from natural signals?
Large Watershed Assessment
How far downstream from alteration points do substantial shifts in streamflow metrics occur?
How sensitive are estuary freshwater inputs to upstream streamflow alterations? Is there a threshold of fresh water alteration below which no signal is detected in an estuary?
- Publications
Below are publications associated with this project.
Filter Total Items: 14An analysis of streamflow trends in the southern and southeastern US from 1950-2015
In this article, the mean daily streamflow at 139 streamflow-gaging stations (sites) in the southern and southeastern United States are analyzed for spatial and temporal patterns. One hundred and thirty-nine individual time-series of mean daily streamflow were reduced to five aggregated time series of Z scores for clusters of sites with similar temporal variability. These aggregated time-series coAuthorsKirk D. Rodgers, Victor L. Roland, Anne B. Hoos, Elena Crowley-Ornelas, Rodney KnightAn interactive data visualization framework for exploring geospatial environmental datasets and model predictions
With the rise of large-scale environmental models comes new challenges for how we best utilize this information in research, management and decision making. Interactive data visualizations can make large and complex datasets easier to access and explore, which can lead to knowledge discovery, hypothesis formation and improved understanding. Here, we present a web-based interactive data visualizatiAuthorsJeffrey D Walker, Benjamin Letcher, Kirk D. Rodgers, Clint C. Muhlfeld, Vincent S. D'AngeloThe use of support vectors from support vector machines for hydrometeorologic monitoring network analyses
Hydrometeorologic monitoring networks are ubiquitous in contemporary earth-system science. Network stakeholders often inquire about the importance of sites and their locations when discussing funding and monitoring design. Support vector machines (SVMs) can be useful by their assigning each monitoring site as either a support or nonsupport vector. A potentiometric surface was created from synthetiAuthorsWilliam H. AsquithCopula theory as a generalized framework for flow-duration curve-based streamflow estimates in ungaged and partially gaged catchments
Flow‐duration curve (FDC) based streamflow estimation methods involve estimating an FDC at an ungaged or partially gaged location and using the time series of nonexceedance probabilities estimated from donor streamgage sites to generate estimates of streamflow. We develop a mathematical framework to illustrate the connection between copulas and prior FDC‐based approaches. The performance of copulaAuthorsScott C. Worland, Scott Steinschneider, William H. Farmer, William H. Asquith, Rodney WhitePrediction and inference of flow-duration curves using multi-output neural networks
We develop multi-output neural network models (MNNs) to predict flow-duration curves (FDCs) in 9,203 ungaged locations in the Southeastern United States for six decades between 1950-2009. The model architecture contains multiple response variables in the output layer that correspond to individual quantiles along the FDC. During training, predictions are made for each quantile, and a combined lossAuthorsScott C. Worland, Scott Steinschneider, William H. Asquith, Rodney Knight, Michael E. WieczorekPutting flow-ecology relationships into practice: A decision-support system to assess fish community response to water-management scenarios
This paper presents a conceptual framework to operationalize flow–ecology relationships into decision-support systems of practical use to water-resource managers, who are commonly tasked with balancing multiple competing socioeconomic and environmental priorities. We illustrate this framework with a case study, whereby fish community responses to various water-management scenarios were predicted iAuthorsJennifer M. Cartwright, Casey Caldwell, Steven Nebiker, Rodney KnightModel calibration criteria for estimating ecological flow characteristics
Quantification of streamflow characteristics in ungauged catchments remains a challenge. Hydrological modeling is often used to derive flow time series and to calculate streamflow characteristics for subsequent applications that may differ from those envisioned by the modelers. While the estimation of model parameters for ungauged catchments is a challenging research task in itself, it is importanAuthorsMarc Vis, Rodney Knight, Sandra Poole, William J. Wolfe, Jan SeibertAccelerating advances in continental domain hydrologic modeling
In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written fromAuthorsStacey A. Archfield, Martyn Clark, Berit Arheimer, Lauren E. Hay, Hilary McMillan, Julie E. Kiang, Jan Seibert, Kirsti Hakala, Andrew R. Bock, Thorsten Wagener, William H. Farmer, Vazken Andreassian, Sabine Attinger, Alberto Viglione, Rodney Knight, Steven L. Markstrom, Thomas M. OverEvaluation of statistical and rainfall-runoff models for predicting historical daily streamflow time series in the Des Moines and Iowa River watersheds
Daily records of streamflow are essential to understanding hydrologic systems and managing the interactions between human and natural systems. Many watersheds and locations lack streamgages to provide accurate and reliable records of daily streamflow. In such ungaged watersheds, statistical tools and rainfall-runoff models are used to estimate daily streamflow. Previous work compared 19 differentAuthorsWilliam H. Farmer, Rodney R. Knight, David A. Eash, Kasey J. Hutchinson, S. Mike Linhart, Daniel E. Christiansen, Stacey A. Archfield, Thomas M. Over, Julie E. KiangEcological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States
Ecological limit functions relating streamflow and aquatic ecosystems remain elusive despite decades of research. We investigated functional relationships between species richness and changes in streamflow characteristics at 662 fish sampling sites in the Tennessee River basin. Our approach included the following: (1) a brief summary of relevant literature on functional relations between fish andAuthorsRodney R. Knight, Jennifer C. Murphy, William J. Wolfe, Charles F. Saylor, Amy K. WalesModelling ecological flow regime: an example from the Tennessee and Cumberland River basins
Predictive equations were developed for 19 ecologically relevant streamflow characteristics within five major groups of flow variables (magnitude, ratio, frequency, variability, and date) for use in the Tennessee and Cumberland River basins using stepbackward regression. Basin characteristics explain 50% or more of the variation for 12 of the 19 equations. Independent variables identified throughAuthorsRodney R. Knight, W. Scott Gain, William J. WolfeInvertebrate response to changes in streamflow hydraulics in two urban areas in the United States
Stream hydrology is foundational to aquatic ecosystems and has been shown to be a structuring element for fish and invertebrates. The relations among urbanization, hydraulics, and invertebrate communities were investigated by the U.S. Geological Survey, National Water-Quality Assessment Program by using measures of stream hydraulics in two areas of the United States. Specifically, the hypothesis tAuthorsRodney R. Knight, Thomas F. Cuffney - Partners
Below are partners associated with this project.