Robert Dudley is a Supervisory Hydrologist in the New England Water Science Center.
Rob's work in recent years has focused on regional and national-scale statistical investigations of climate-related trends and variability of surface waters and groundwaters, probabilistic forecasting, and developing methods for computing river flows using satellite imagery and altimetry data.
Science and Products
Long-Term Data Collection Provides Insight to Changes in Water Resources in New England
Primarily through the efforts of Glenn Hodgkins and Robert Dudley, the New England Water Science Center has been studying historical changes in streamflows, groundwater levels, and lake ice in New England and across the country for 20 years. Glenn and Rob have analyzed a wealth of historical data, including 100+ years of streamflow data and 150+ years of lake-ice data at some locations...
Hydrologic Interpretive Program
The mission of the Hydrologic Interpretive Program is to work with stakeholders to design, carry out, and publish scientific studies addressing critical water-resources issues facing New England and the Nation.
Trend Reproduction
As part of the National Water Budget Project, our objective is to quantify how well observed trends are simulated.
HBMI PRMS Project
This project will provide a deterministic watershed model of the Meduxnekeag River watershed with a capacity to model water-temperatures capable of simulating future hydrologic and temperature changes based on projected climate estimates.
EPA National Low Flows
Low streamflow has great ecological importance as it defines the minimum extent (and carrying capacity) of in-stream habitat and affects biota composition and distribution, and species trophic structure.
Hydrologic Climate Change Indicators
Background Streams and rivers are an important environmental resource and provide water for many human needs. Streamflow is a measure of the volume of water carried by rivers and streams. Changes in streamflow can directly influence the supply of water available for human consumption, irrigation, generating electricity, and other needs. In addition, many plants and animals depend on streamflow
Webinar: Historical Trends in Summer Precipitation, Baseflows, and Stormflows in New England and Projections of Seasonal Streamflows for Coastal Streams in Maine
Check out this webinar for more information on influencing water flow in Maine rivers and streams.
Impact of Changes in Streamflow and Temperature on Endangered Atlantic Salmon
Coastal rivers draining into the Gulf of Maine are home to the endangered Gulf of Maine Distinct Population Segment of Atlantic salmon. The Gulf of Maine population began to decline significantly by the late 19th century, leading to the closure of the commercial Atlantic salmon fishery in 1948. In recent years, populations have again begun to decrease again. State and federal fisheries biologists
Modeled and observed trends in streamflows at managed basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
This data release contains trend results computed on the basis of modeled and observed daily streamflows at 1,257 gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Study gages were selected from the GAGES-II dataset of gages classified as non-reference which means streamflows may be affected by human influence. Modeled daily streamflows were computed using the det
Modeled and observed trends at reference basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
This data release contains trend results computed on the basis of modeled and observed daily streamflows at 502 reference gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-Co
Peak-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 slop
Low-streamflow trends and basin characteristics for 2,482 U.S. Geological Survey streamgages in the conterminous U.S.
This data release contains drainage basin characteristics and low-streamflow trend results for 2,482 U.S. Geological Survey (USGS) streamgages in the conterminous U.S. Data include streamgage identification number, name, drainage area, latitude, longitude, percent developed land use, percent crop land use, dam storage, streamgage classification, record completeness status, and trend slopes and sig
Data related to the degree of potential human influence near 2228 groundwater wells in the U.S. glacial aquifer system
This dataset contains information on the degree of potential human influence near 2228 groundwater wells in the U.S. glacial aquifer system. Data include well identification, name, latitude, longitude, potential-human-influence category, percent urban and crop land use in a 500 meter radius around each well, and measures of county-based groundwater use and irrigation.
Velocity, depth, and selected water quality profiles of the Lower Penobscot River Estuary in Maine, 2017
This data release includes transect data comprising velocity and depths collected by use of an acoustic-doppler current profiler (ADCP), and vertical profile data comprising conductivity, temperature, and depth by use of a conductivity, temperature, and depth (CTD) instrument, as well as tide elevation data at specified locations in the lower Penobscot River and Penobscot Bay (the Penobscot River
Model climate scenario output for the Farmington river basin, Connecticut and Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing five EPA-selected future climate change scenarios for the Farmington River Basin in Massachusetts and Connecticut. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool (WMOST) modeling. Climate scenarios, based on 2036-2065 changes fro
Generalized linear models and input data for forecasting the probability of groundwater levels declining below specified low thresholds for the conterminous U.S.
This dataset contains model parameters and input data (.rdata files) for 258 models derived for wells in the conterminous United States. The models are generalized linear models with a binomial response variable (logistic regression) for forecasting the probability of groundwater levels declining or maintaining below specified low thresholds for any time of the year for forecast time horizons from
Model climate scenario output Upper Charles river basin, Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing 5 EPA-selected future climate change scenarios for the Upper Charles River Basin in Massachusetts. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool (WMOST) modeling. Climate scenarios, based on 2036-2065 changes from 1975-2004 for
Model climate scenario output for the Blackstone, Pawcatuck, and Ipswich river basins, Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing 5 EPA-selected future climate change scenarios for each of three river basins: Blackstone in Massachusetts and Rhode Island, Pawcatuck in Rhode Island, and Ispwich in Massachusetts. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool
Filter Total Items: 71
Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
We present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August baseflow per unit
Exploring the factors controlling the error characteristics of the Surface Water and Ocean Topography mission discharge estimates
The Surface Water and Ocean Topography (SWOT) satellite mission will measure river width, water surface elevation, and slope for rivers wider than 50-100 m. SWOT observations will enable estimation of river discharge by using simple flow laws such as the Manning-Strickler equation, complementing in-situ streamgages. Several discharge inversion algorithms designed to compute unobserved flow law par
Comparing trends in modeled and observed streamflows at minimally altered basins in the United States
We compared modeled and observed streamflow trends from 1984–2016 using five statistical transfer models and one deterministic, distributed-parameter, process-based model, for 26 flow metrics at 502 basins in the United States that are minimally influenced by development. We also looked at a measure of overall model fit and average bias. A higher percentage of basins, for all models, had relativel
Atlantic Salmon (Salmo salar) climate scenario planning pilot report
Scenario planning is a structured process that embraces uncertainty and explores plausible alternative future conditions under different assumptions to help manage risk and prioritize actions ( Schwartz 1996, Peterson et al. 2003). It has been used by a variety of organizations to explore and help prepare for the future, lends itself well to exploring the uncertainty surrounding changing environme
Change points in annual peak streamflows: Method comparisons and historical change points in the United States
Change-point, or step-trend, detection is an active area of research in statistics and an area of great interest in hydrology because change points may be evidence of natural or anthropogenic changes in climatic, hydrologic, or landscape processes. A common change-point technique is the Pettitt test; however, many change-point methods are now available and testing of methods has been limited. This
Low streamflow trends at human-impacted and reference basins in the United States
We present a continent-scale exploration of trends in annual 7-day low streamflows at 2482 U.S. Geological Survey streamgages across the conterminous United States over the past 100, 75, and 50 years (1916–2015, 1941–2015 and 1966–2015). We used basin characteristics to identify subsets of study basins representative of reference basins with streamflow relatively free from human effects (n = 259),
Historical trend in the ratio of solid to total precipitation
No abstract available
Updating estimates of low-streamflow statistics to account for possible trends
Accurate estimators of streamflow statistics are critical to the design, planning, and management of water resources. Given increasing evidence of trends in low-streamflow, new approaches to estimating low-streamflow statistics are needed. Here we investigate simple approaches to select a recent subset of the low-flow record to update the commonly used statistic of 7Q10, the annual minimum 7-day s
Drought forecasting for streams and groundwaters in northeastern United States
BackgroundWhen rainfall is lower than normal over an extended period, streamflows decline, groundwater levels fall, and hydrological drought can occur. Droughts can reduce the water available for societal needs, such as public and private drinking-water supplies, farming, and industry, and for ecological health, such as maintenance of water quality and natural ecosystems. Recent droughts in the no
Generalized hydrogeologic framework and groundwater budget for a groundwater availability study for the glacial aquifer system of the United States
The glacial aquifer system groundwater availability study seeks to quantify (1) the status of groundwater resources in the glacial aquifer system, (2) how these resources have changed over time, and (3) likely system response to future changes in anthropogenic and environmental conditions. The glacial aquifer system extends from Maine to Alaska, although the focus of this report is the part of the
Groundwater-level trends in the U.S. glacial aquifer system, 1964-2013
The glacial aquifer system in the United States is a major source of water supply but previous work on historical groundwater trends across the system is lacking. Trends in annual minimum, mean, and maximum groundwater levels for 205 monitoring wells were analyzed across three regions of the system (East, Central, West Central) for four time periods: 1964-2013, 1974-2013, 1984-2013, and 1994-2013.
Forecasting the probability of future groundwater levels declining below specified low thresholds in the conterminous U.S.
We present a logistic regression approach for forecasting the probability of future groundwater levels declining or maintaining below specific groundwater-level thresholds. We tested our approach on 102 groundwater wells in different climatic regions and aquifers of the United States that are part of the U.S. Geological Survey Groundwater Climate Response Network. We evaluated the importance of cu
Pre-USGS Publications
Dudley, R.W., Panchang, V.G., and Newell, C.R., 2000. Application of a comprehensive modeling strategy for the management of net-pen aquaculture waste transport: Aquaculture, Elsevier Science, (187) 3-4 (2000) p. 319-349.
Dudley, R.W., Panchang, V.G., Newell, C.R., 1998. AWATS: A Net-Pen Aquaculture Waste Transport Simulator for Management Purposes: Proceedings of the twenty-sixth US-Japan Aquaculture Symposium, Durham, New Hampshire, September 16-18, 1997, US-Japan Cooperative Program in Natural Resources (UJNR) Technical Report no. 26, Ed. W. H. Howell et al., NOAA Central Library Call Number: SH3 .U5 1998, pp 215-228.
altimDSWE and RSQcomp R Packages For Remote Sensing Discharge
Projects and apps to support computation of stream discharge using remotely-sensed satellite data. (RSQ, Remotely Sensed Discharge):
altimDSWE: Shiny app tool to support development of relations between satellite altimetry and DSWE data
RSQcomp: Shiny app tool for computing stream discharge using remotely sensed data
Science and Products
- Science
Long-Term Data Collection Provides Insight to Changes in Water Resources in New England
Primarily through the efforts of Glenn Hodgkins and Robert Dudley, the New England Water Science Center has been studying historical changes in streamflows, groundwater levels, and lake ice in New England and across the country for 20 years. Glenn and Rob have analyzed a wealth of historical data, including 100+ years of streamflow data and 150+ years of lake-ice data at some locations...Hydrologic Interpretive Program
The mission of the Hydrologic Interpretive Program is to work with stakeholders to design, carry out, and publish scientific studies addressing critical water-resources issues facing New England and the Nation.Trend Reproduction
As part of the National Water Budget Project, our objective is to quantify how well observed trends are simulated.HBMI PRMS Project
This project will provide a deterministic watershed model of the Meduxnekeag River watershed with a capacity to model water-temperatures capable of simulating future hydrologic and temperature changes based on projected climate estimates.EPA National Low Flows
Low streamflow has great ecological importance as it defines the minimum extent (and carrying capacity) of in-stream habitat and affects biota composition and distribution, and species trophic structure.Hydrologic Climate Change Indicators
Background Streams and rivers are an important environmental resource and provide water for many human needs. Streamflow is a measure of the volume of water carried by rivers and streams. Changes in streamflow can directly influence the supply of water available for human consumption, irrigation, generating electricity, and other needs. In addition, many plants and animals depend on streamflowWebinar: Historical Trends in Summer Precipitation, Baseflows, and Stormflows in New England and Projections of Seasonal Streamflows for Coastal Streams in Maine
Check out this webinar for more information on influencing water flow in Maine rivers and streams.Impact of Changes in Streamflow and Temperature on Endangered Atlantic Salmon
Coastal rivers draining into the Gulf of Maine are home to the endangered Gulf of Maine Distinct Population Segment of Atlantic salmon. The Gulf of Maine population began to decline significantly by the late 19th century, leading to the closure of the commercial Atlantic salmon fishery in 1948. In recent years, populations have again begun to decrease again. State and federal fisheries biologists - Data
Modeled and observed trends in streamflows at managed basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
This data release contains trend results computed on the basis of modeled and observed daily streamflows at 1,257 gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Study gages were selected from the GAGES-II dataset of gages classified as non-reference which means streamflows may be affected by human influence. Modeled daily streamflows were computed using the detModeled and observed trends at reference basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
This data release contains trend results computed on the basis of modeled and observed daily streamflows at 502 reference gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-CoPeak-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 slopLow-streamflow trends and basin characteristics for 2,482 U.S. Geological Survey streamgages in the conterminous U.S.
This data release contains drainage basin characteristics and low-streamflow trend results for 2,482 U.S. Geological Survey (USGS) streamgages in the conterminous U.S. Data include streamgage identification number, name, drainage area, latitude, longitude, percent developed land use, percent crop land use, dam storage, streamgage classification, record completeness status, and trend slopes and sigData related to the degree of potential human influence near 2228 groundwater wells in the U.S. glacial aquifer system
This dataset contains information on the degree of potential human influence near 2228 groundwater wells in the U.S. glacial aquifer system. Data include well identification, name, latitude, longitude, potential-human-influence category, percent urban and crop land use in a 500 meter radius around each well, and measures of county-based groundwater use and irrigation.Velocity, depth, and selected water quality profiles of the Lower Penobscot River Estuary in Maine, 2017
This data release includes transect data comprising velocity and depths collected by use of an acoustic-doppler current profiler (ADCP), and vertical profile data comprising conductivity, temperature, and depth by use of a conductivity, temperature, and depth (CTD) instrument, as well as tide elevation data at specified locations in the lower Penobscot River and Penobscot Bay (the Penobscot RiverModel climate scenario output for the Farmington river basin, Connecticut and Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing five EPA-selected future climate change scenarios for the Farmington River Basin in Massachusetts and Connecticut. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool (WMOST) modeling. Climate scenarios, based on 2036-2065 changes froGeneralized linear models and input data for forecasting the probability of groundwater levels declining below specified low thresholds for the conterminous U.S.
This dataset contains model parameters and input data (.rdata files) for 258 models derived for wells in the conterminous United States. The models are generalized linear models with a binomial response variable (logistic regression) for forecasting the probability of groundwater levels declining or maintaining below specified low thresholds for any time of the year for forecast time horizons fromModel climate scenario output Upper Charles river basin, Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing 5 EPA-selected future climate change scenarios for the Upper Charles River Basin in Massachusetts. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool (WMOST) modeling. Climate scenarios, based on 2036-2065 changes from 1975-2004 forModel climate scenario output for the Blackstone, Pawcatuck, and Ipswich river basins, Massachusetts, 2036-2065 change from 1975-2004, Representative Concentration Pathways 4.5 and 8.5
This data release provides a set of Hydrological Simulation Program--Fortran (HSPF) model files representing 5 EPA-selected future climate change scenarios for each of three river basins: Blackstone in Massachusetts and Rhode Island, Pawcatuck in Rhode Island, and Ispwich in Massachusetts. Output from these models are intended for use as input to EPA Watershed Management Optimization Support Tool - Publications
Filter Total Items: 71
Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
We present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August baseflow per unitExploring the factors controlling the error characteristics of the Surface Water and Ocean Topography mission discharge estimates
The Surface Water and Ocean Topography (SWOT) satellite mission will measure river width, water surface elevation, and slope for rivers wider than 50-100 m. SWOT observations will enable estimation of river discharge by using simple flow laws such as the Manning-Strickler equation, complementing in-situ streamgages. Several discharge inversion algorithms designed to compute unobserved flow law parComparing trends in modeled and observed streamflows at minimally altered basins in the United States
We compared modeled and observed streamflow trends from 1984–2016 using five statistical transfer models and one deterministic, distributed-parameter, process-based model, for 26 flow metrics at 502 basins in the United States that are minimally influenced by development. We also looked at a measure of overall model fit and average bias. A higher percentage of basins, for all models, had relativelAtlantic Salmon (Salmo salar) climate scenario planning pilot report
Scenario planning is a structured process that embraces uncertainty and explores plausible alternative future conditions under different assumptions to help manage risk and prioritize actions ( Schwartz 1996, Peterson et al. 2003). It has been used by a variety of organizations to explore and help prepare for the future, lends itself well to exploring the uncertainty surrounding changing environmeChange points in annual peak streamflows: Method comparisons and historical change points in the United States
Change-point, or step-trend, detection is an active area of research in statistics and an area of great interest in hydrology because change points may be evidence of natural or anthropogenic changes in climatic, hydrologic, or landscape processes. A common change-point technique is the Pettitt test; however, many change-point methods are now available and testing of methods has been limited. ThisLow streamflow trends at human-impacted and reference basins in the United States
We present a continent-scale exploration of trends in annual 7-day low streamflows at 2482 U.S. Geological Survey streamgages across the conterminous United States over the past 100, 75, and 50 years (1916–2015, 1941–2015 and 1966–2015). We used basin characteristics to identify subsets of study basins representative of reference basins with streamflow relatively free from human effects (n = 259),Historical trend in the ratio of solid to total precipitation
No abstract availableUpdating estimates of low-streamflow statistics to account for possible trends
Accurate estimators of streamflow statistics are critical to the design, planning, and management of water resources. Given increasing evidence of trends in low-streamflow, new approaches to estimating low-streamflow statistics are needed. Here we investigate simple approaches to select a recent subset of the low-flow record to update the commonly used statistic of 7Q10, the annual minimum 7-day sDrought forecasting for streams and groundwaters in northeastern United States
BackgroundWhen rainfall is lower than normal over an extended period, streamflows decline, groundwater levels fall, and hydrological drought can occur. Droughts can reduce the water available for societal needs, such as public and private drinking-water supplies, farming, and industry, and for ecological health, such as maintenance of water quality and natural ecosystems. Recent droughts in the noGeneralized hydrogeologic framework and groundwater budget for a groundwater availability study for the glacial aquifer system of the United States
The glacial aquifer system groundwater availability study seeks to quantify (1) the status of groundwater resources in the glacial aquifer system, (2) how these resources have changed over time, and (3) likely system response to future changes in anthropogenic and environmental conditions. The glacial aquifer system extends from Maine to Alaska, although the focus of this report is the part of theGroundwater-level trends in the U.S. glacial aquifer system, 1964-2013
The glacial aquifer system in the United States is a major source of water supply but previous work on historical groundwater trends across the system is lacking. Trends in annual minimum, mean, and maximum groundwater levels for 205 monitoring wells were analyzed across three regions of the system (East, Central, West Central) for four time periods: 1964-2013, 1974-2013, 1984-2013, and 1994-2013.Forecasting the probability of future groundwater levels declining below specified low thresholds in the conterminous U.S.
We present a logistic regression approach for forecasting the probability of future groundwater levels declining or maintaining below specific groundwater-level thresholds. We tested our approach on 102 groundwater wells in different climatic regions and aquifers of the United States that are part of the U.S. Geological Survey Groundwater Climate Response Network. We evaluated the importance of cuPre-USGS Publications
Dudley, R.W., Panchang, V.G., and Newell, C.R., 2000. Application of a comprehensive modeling strategy for the management of net-pen aquaculture waste transport: Aquaculture, Elsevier Science, (187) 3-4 (2000) p. 319-349.Dudley, R.W., Panchang, V.G., Newell, C.R., 1998. AWATS: A Net-Pen Aquaculture Waste Transport Simulator for Management Purposes: Proceedings of the twenty-sixth US-Japan Aquaculture Symposium, Durham, New Hampshire, September 16-18, 1997, US-Japan Cooperative Program in Natural Resources (UJNR) Technical Report no. 26, Ed. W. H. Howell et al., NOAA Central Library Call Number: SH3 .U5 1998, pp 215-228. - Software
altimDSWE and RSQcomp R Packages For Remote Sensing Discharge
Projects and apps to support computation of stream discharge using remotely-sensed satellite data. (RSQ, Remotely Sensed Discharge): altimDSWE: Shiny app tool to support development of relations between satellite altimetry and DSWE data RSQcomp: Shiny app tool for computing stream discharge using remotely sensed data