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
Satellite-based Remote Sensing of River Discharge
Predictive Analysis of Water Demand for Providence, Rhode Island
The Impact of Climate Change on Culturally Significant Wetland Plants and Their Habitat in the Meduxnekeag River Watershed in Maine
Long-Term Data Collection Provides Insight to Changes in Water Resources in New England
Hydrologic Interpretive Program
Trend Reproduction
HBMI PRMS Project
EPA National Low Flows
Hydrologic Climate Change Indicators
Webinar: Historical Trends in Summer Precipitation, Baseflows, and Stormflows in New England and Projections of Seasonal Streamflows for Coastal Streams in Maine
Impact of Changes in Streamflow and Temperature on Endangered Atlantic Salmon
Selected Inputs of Siting Considerations for Satellite Observation of River Discharge
Computed Streamflow Using Satellite Data for the Copper, Nushagak, Tanana, Yukon, Susitna, and Knik, Koyukuk Rivers, Alaska, 2008-2021
U.S. Streamflow Drought During the Last Century: annual drought and low flow metrics, annual climate, and trends for the periods 1921-2020, 1951-2020 and 1981-2020
Modeled and observed trends in streamflows at managed basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
Attributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
Modeled and observed trends at reference basins in the conterminous U.S. from October 1, 1983 through September 30, 2016
Peak-streamflow trends and change-points and basin characteristics for 2,683 U.S. Geological Survey streamgages in the conterminous U.S.
Low-streamflow trends and basin characteristics for 2,482 U.S. Geological Survey streamgages in the conterminous U.S.
Data related to the degree of potential human influence near 2228 groundwater wells in the U.S. glacial aquifer system
Velocity, depth, and selected water quality profiles of the Lower Penobscot River Estuary in Maine, 2017
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
Generalized linear models and input data for forecasting the probability of groundwater levels declining below specified low thresholds for the conterminous U.S.
Groundwater recharge in northern New England: Meteorological drivers and relations with low streamflow
Going beyond low flows: Streamflow drought deficit and duration illuminate distinct spatiotemporal drought patterns and trends in the U.S. during the last century
Methods for computing 7Q2 and 7Q20 low-streamflow statistics to account for possible trends
Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
Exploring the factors controlling the error characteristics of the Surface Water and Ocean Topography mission discharge estimates
Comparing trends in modeled and observed streamflows at minimally altered basins in the United States
Atlantic Salmon (Salmo salar) climate scenario planning pilot report
Change points in annual peak streamflows: Method comparisons and historical change points in the United States
Low streamflow trends at human-impacted and reference basins in the United States
Historical trend in the ratio of solid to total precipitation
Updating estimates of low-streamflow statistics to account for possible trends
Drought forecasting for streams and groundwaters in northeastern United States
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
altimDSWE and RSQcomp R Packages For Remote Sensing Discharge
Drought Forecasting for Groundwater in Northeastern US
This application allows the display and query of groundwater drought probabilities for Northeast region wells. This application allows users to view, query, select, and export groundwater drought probabilities for next three months.
Science and Products
- Science
Satellite-based Remote Sensing of River Discharge
The U.S. Geological Survey and NASA are collaborating on a study to develop methods to estimate river flows from satellite observations.Predictive Analysis of Water Demand for Providence, Rhode Island
The Providence Water Supply Board (Providence Water) and the U.S. Geological Survey (USGS) are collaborating on a study to predict future water demand in and around the city of Providence.The Impact of Climate Change on Culturally Significant Wetland Plants and Their Habitat in the Meduxnekeag River Watershed in Maine
Wetland plants are important to Wabanaki people in Maine and are central to Houlton Band of Maliseet Indian (HBMI) identity. HBMI peoples have harvested culturally important plants within the Meduxnekeag watershed for generations. Basket making and medicinal plant harvesting are forms of cultural preservation that are also important to Tribal economies. Projections for climate change in the noLong-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
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Selected Inputs of Siting Considerations for Satellite Observation of River Discharge
Uncertainty of satellite discharge estimates is affected by choice of satellite sensor, hydraulic variable for observation, and discharge estimation algorithm, as well as the availability of ground-calibration data. Site selection is very important for reducing error and uncertainty in both conventional and satellite-based discharge measurements because geomorphic river characteristics have strongComputed Streamflow Using Satellite Data for the Copper, Nushagak, Tanana, Yukon, Susitna, and Knik, Koyukuk Rivers, Alaska, 2008-2021
Relations between satellite altimetry water-surface elevation data and dynamic surface water extent data derived from LANDSAT imagery data were used with a modified Manning's equation to compute remotely sensed streamflows (RSQ) at locations on the Tanana, Yukon, Susitna, Nushagak, Copper, Koyukuk and Knik Rivers in Alaska using satellite data. Data are organized into zip archives named for each sU.S. Streamflow Drought During the Last Century: annual drought and low flow metrics, annual climate, and trends for the periods 1921-2020, 1951-2020 and 1981-2020
This dataset contains annual flow metrics quantifying drought and low streamflows for USGS GAGES-2 gages in the contiguous U.S. satisfying data completeness checks for the periods 1921-2020, 1951-2020, and 1981-2020. The dataset also contains annual climate variables from the USGS Monthly Water Balance Model (MWBM). The dataset provides trend analysis outputs for annual drought and low flow metricModeled 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 detAttributions 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 waModeled 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 from - Publications
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Groundwater recharge in northern New England: Meteorological drivers and relations with low streamflow
Meteorological drivers of groundwater recharge for spring (February–June), fall (October–January), and recharge-year (October–June) recharge seasons were evaluated for northern New England and upstate New York from 1989 to 2018. Monthly groundwater recharge was computed at 21 observation wells by subtracting the water levels at the end of each month from the level of the previous month; only positAuthorsCaitlin Crossett, Glenn A. Hodgkins, Hadley Menk, Lesley-Ann L. Dupigny-Giroux, Robert W. Dudley, Mary D. Lemcke-Stampone, John C. HammondGoing beyond low flows: Streamflow drought deficit and duration illuminate distinct spatiotemporal drought patterns and trends in the U.S. during the last century
Streamflow drought is a recurring challenge, and understanding spatiotemporal patterns of past droughts is needed to manage future water resources. We examined regional patterns in streamflow drought metrics and compared these metrics to low flow timing and magnitude using long-term daily records for 555 minimally disturbed watersheds. For each streamgage, we calculated streamflow drought durationAuthorsJohn C. Hammond, Caelan E. Simeone, Jory Seth Hecht, Glenn A. Hodgkins, Melissa Lombard, Gregory J. McCabe, David M. Wolock, Michael Wieczorek, Carolyn G Olson, Todd Caldwell, Robert W. Dudley, Adam N. PriceMethods for computing 7Q2 and 7Q20 low-streamflow statistics to account for possible trends
Low-streamflow statistics, such as the annual minimum 7-day streamflow (which is the 7-day streamflow likely to be exceeded in 9 out of 10 years on average [7Q10]), that are computed by using the full historical streamflow record may not accurately represent current conditions at sites with statistically significant trends in low streamflow over time. Recent research suggests that using a contempoAuthorsLuther Schalk, Robert W. Dudley, Annalise G. BlumModel 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 unitAuthorsPamela J. Lombard, Robert W. Dudley, Matthias J. Collins, Rory Saunders, Ernie AtkinsonExploring 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 parAuthorsRenato Frasson, Michael T. Durand, Kevin Lanier, Colin Gleason, Konstantinos Andreadis, Mark Hageman, Robert W. Dudley, David M. Bjerklie, Hind Oubanas, Pierre-André Garambois, Pierre-Olivier Malaterre, Peirong Lin, Tamlin M. Pavelsky, Jerome Monnier, Craig Binkerhoff, Cedric H. DavidComparing 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 relativelAuthorsGlenn A. Hodgkins, Robert W. Dudley, Amy M. Russell, Jacob H. LaFontaineAtlantic 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 environmeAuthorsDiane Borggaard, Dori Dick, Jonathan Star, Mike Alexander, M. Bernier, Matt Collins, Kelly Damon-Randall, Robert W. Dudley, Roger Roger Griffis, Sean Hayes, Mike Johnson, Dan Kircheis, John Kocik, Benjamin Letcher, Nate Mantua, Wendy Morrison, Keith Nislow, Vince Saba, R. Saunders, Tim Sheehan, Michelle D. StaudingerChange 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. ThisAuthorsKaren R. Ryberg, Glenn A. Hodgkins, Robert W. DudleyLow 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),AuthorsRobert W. Dudley, Robert M. Hirsch, Stacey A. Archfield, Annalise G. Blum, Benjamin RenardHistorical trend in the ratio of solid to total precipitation
No abstract availableAuthorsThomas G. Huntington, Glenn A. Hodgkins, B.D. Keim, Robert W. DudleyUpdating 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 sAuthorsAnnalise G. Blum, Stacey A. Archfield, Robert M. Hirsch, Richard M Vogel, Julie E. Kiang, Robert W. DudleyDrought 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 noAuthorsSamuel H. Austin, Robert W. DudleyNon-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.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- 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 - News
- Web Tools
Drought Forecasting for Groundwater in Northeastern US
This application allows the display and query of groundwater drought probabilities for Northeast region wells. This application allows users to view, query, select, and export groundwater drought probabilities for next three months.