Robert Regan

Robert Regan

Hydrologist

Water

Email: rsregan@usgs.gov
Phone: 303-236-5008

Address:
W 6th Ave Kipling St
Lakewood, CO 80225


Expertise

Biography

PRESENT ADDRESS:

U.S. Geological Survey

National Research Program

Denver Federal Center, Box 25046, MS 412

Denver, Colorado 80225

 

EDUCATION:

Masters of Divinity (2000). Wesley Theological Seminary, Washington, D.C.

BA Environmental Science (1987). University of Virginia, Charlottesville, Virginia,

PRESENT ASSIGNMENT:

DATES From: 2003 To: Present

DESCRIPTION: Research and development focuses on incorporating new simulation algorithms and enhancements of existing algorithms within the Precipitation-Runoff Modeling System (PRMS) and the coupled Modular Groundwater Flow Model (MODFLOW) and PRMS simulation model—GSFLOW. This development work is and cooperative effort between the MOWS project, the Office of Groundwater, and researchers in the Nevada Water Science Center. Development is driven by MOWS research objectives of improving the understanding and simulation of watershed-scale hydrologic processes to climate and anthropogenic influences and environmental characteristics with input and requests from USGS and other Federal agency academic and private sector scientists.

 

RELEVANT EXPERIENCE:

Research and development of the PRMS simulation model, most recently developing methods for input of historic and projected climate; dynamic parameters; and water-use information and enhancement of surface-depression storage and spatial and temporal characterization of model parameters for use in large model domains.

Research and development of the coupled groundwater/surface-water simulation model (GSFLOW) and MODFLOW/UZF Package.

Research and development of a loosely-coupled, sub-daily simulation model using PRMS, NOAA-NWS Lag and K river routing model, and USACE HEC-ResSim Reservoir System Simulation model for a large watershed spanning portions of NY, NJ, and PA.

 

Hydrologist, member of the Modeling of Watershed Systems (MoWS) project, USGS National Research Program, Central Region, Lakewood, Colorado (2003-present)

Senior Pastor, Greenwood United Methodist Church, Winchester, Virginia (1999-2002)

Hydrologist, project chief and member of the Hydrologic Analysis Software Support Section, Reston, Virginia (1992-1996)

Computer Scientist, project chief and site admistrator USGS National Research Program, Northeast Region, Office of Surface Water, Office of Groundwater, and Office of Water Quality, Reston, Virginia (1986-1992)

Hydrologist, member of the Modeling of Hydrodynamic Systems project, USGS National Research Program, Northeast Region, Reston, Virginia (1981-1986)

 

 

 

 

 

Publications

Markstrom, Steven L.; Regan, Robert S.; Hay, Lauren E.; Viger, Roland J.; Webb, Richard M.; Payn, Robert A.; LaFontaine, Jacob H., 2015. PRMS-IV, the precipitation-runoff modeling system, version 4. U.S. Geological Survey Techniques and Methods 6-B7, vii, 158 p. [Link]

Fulton, John W.; Risser, Dennis W.; Regan, Robert S.; Walker, John F.; Hunt, Randall J.; Niswonger, Richard G.; Hoffman, Scott A.; Markstrom, Steven, 2015. Water-budgets and recharge-area simulations for the Spring Creek and Nittany Creek Basins and parts of the Spruce Creek Basin, Centre and Huntingdon Counties, Pennsylvania, Water Years 2000–06. U.S. Geological Survey Scientific Investigations Report 2015-5073, x, 86 p. [Link]

Regan, Robert S.; Niswonger, Richard G.; Markstrom, Steven L.; Barlow, Paul M., 2015. Documentation of a restart option for the U.S. Geological Survey coupled Groundwater and Surface-Water Flow (GSFLOW) model. U.S. Geological Survey Techniques and Methods 6-D3, vii, 19 p. [Link]

LaFontaine, Jacob H., Lauren E. Hay, Roland J. Viger, R. Steve Regan, and Steven L. Markstrom,2015. Effects of Climate and Land Cover on Hydrology in the Southeastern U.S.: Potential Impacts on Watershed Planning. Journal of the American Water Resources Association (JAWRA) 51(5):1235-1261. DOI: 10.1111/1752-1688.12304 [Link]

Henson, Wesley R.; Medina, Rose L.; Mayers, C. Justin; Niswonger, Richard G.; Regan, R. S., 2013. CRT--Cascade Routing Tool to define and visualize flow paths for grid-based watershed models. U.S. Geological Survey Techniques and Methods 6-D2, Pamphlet: vii, 28 p.; Software [Link]

LaFontaine, Jacob H.; Hay, Lauren E.; Viger, Roland J.; Markstrom, Steve L.; Regan, R. Steve; Elliott, Caroline M.; Jones, John W., 2013. Application of the Precipitation-Runoff Modeling System (PRMS) in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States. U.S. Geological Survey Scientific Investigations Report 2013-5162, ix, 118 p. [Link]

Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, Robert S., 2013. Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin. U.S. Geological Survey Scientific Investigations Report 2013-5159, vi, 118 p. [Link]

Fulton, J.W., Risser, D.W., Regan, R.S., Hoffman, S.A., Markstrom, S.L., Walker, J.F., and Hunt, R.J., 2013, GSFLOW-derived water budgets for the Spring Creek and Nittany Creek Basins and parts of the Spruce Creek Basin, Centre and Huntingdon Counties, Pennsylvania, 2000-06. U.S. Geological Survey Scientific Investigations Report 2013–XXXX, XX p.

Markstrom, Steven L.; Hay, Lauren E.; Ward-Garrison, D. Christian; Risley, John C.; Battaglin, William A.; Bjerklie, David M.; Chase, Katherine J.; Christiansen, Daniel E.; Dudley, Robert W.; Hunt, Randall J.; Koczot, Kathryn M.; Mastin, Mark C.; Regan, R. Steven; Viger, Roland J.; Vining, Kevin C.; Walker, John F., 2012. Integrated watershed-scale response to climate change for selected basins across the United States. U.S. Geological Survey Scientific Investigations Report 2011-5077, x, 134 p.; Appendix [Link]

Markstrom, Steven L.; Hay, Lauren E.; Regan, R. Steven, 2012. Watershed scale response to climate change--Sagehen Creek Basin, California. U.S. Geological Survey Fact Sheet 2011-3121, 6 p. [Link]

Hevesi, Joseph A.; Woolfenden, Linda R.; Niswonger, Richard G.; Regan, R. Steven; Nishikawa, Tracy, 2011. Decoupled application of the integrated hydrologic model, GSFLOW, to estimate agricultural irrigation in the Santa Rosa Plain, California. Integrated GroundWater Modeling Center , 5 p. [Link]

Markstrom, Steven L.; Hay, Lauren E.; Regan, R. Steven., 2011, Watershed scale response to climate change--Sagehen Creek Basin, California, USGS Fact Sheet: 2011-3121 [Link]

Goode, D.J., Koerkle, E.H., Hoffman, S.A., Regan, R.S., Hay, L.E., and Markstrom, S.L., 2010, Simulation of Runoff and Reservoir Inflow for Use in a Flood-Analysis Model for the Delaware River, Pennsylvania, New Jersey, and New York, 2004-2006: U.S. Geological Survey Open-File Report 2010-1014, 68 p. [Link]

Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M., 2008. GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005). Geological Survey (U.S.) Techniques and Methods 6-D1, x, 240 p. [Link]

Niswonger, Richard G.; Prudic, David E.; Regan, R. Steven, 2006. Documentation of the Unsaturated-Zone Flow (UZF1) Package for modeling Unsaturated Flow Between the Land Surface and the Water Table with MODFLOW-2005. Techniques and Methods 6-A19, 74 p.; 14 figs.; 8 tables [Link]

Regan, R. S.; Schaffranek, R. W.; Baltzer, R. A., 1996. Time-dependent Data System (TDDS); an interactive program to assemble, manage, and appraise input data and numerical output of flow/transport simulation models. U.S. Geological Survey ; Branch of Information Services [distributor], Water-Resources Investigations Report 96-4143, vii, 104 p. :ill. ;28 cm.

Regan, R. S.; Schaffranek, R. W., 1985. A computer program for analyzing channel geometry. U.S. Geological Survey ; Open-File Services Section, Western Distribution Branch, Water-Resources Investigations Report 85-4335, v, 49 p. :ill. ;28 cm.

Past Publications:

  1. Markstrom, S.L., Regan, R.S., Niswonger, R.G., and Prudic, D.E., 2006, GSFLOW?A basin-scale model for coupled simulation of ground-water and surface-water flow?Part A. Concepts for modeling surface-water flow with the U.S. Geological Survey Precipitation-Runoff Modeling System model: 3 rd Federal Hydrologic Modeling Conference, Reno, NV. 
  2. Markstrom, S.L., Niswonger, R.G., Regan, R.S., Prudic, D.E., Barlow, P.M., Pohll, G., and Viger, R.J., in preparation, GSFLOW: Integration of the Precipitation-Runoff Modeling System (PRMS) with the Modular Ground-Water Flow Model , U.S. Geological Survey Techniques and Methods Book 6, Section D, Chapter 1.
  3. Niswonger, R.G., and Prudic, D.E., Markstrom, S.L., and Regan, R.S., 2006, GSFLOW?A basin-scale model for coupled simulation of ground-water and surface-water flow?Part B. Concepts for modeling ground-water flow with the U.S. Geological Survey MODFLOW model: 3 rd Federal Hydrologic Modeling Conference, Reno, NV. 
  4. Niswonger, R.G., Prudic, D.E., and Regan, R.S., in review, Documentation of the Unsaturated Flow (UZF1) Package for modeling percolation between the land surface and the water table with MODFLOW-2000: U.S. Geological Techniques and Methods Book 6, Chapter A1X.
  5. Niswonger, R.G, Regan, R.S., Prudic, D.E., Markstrom, S.L., Pohll, Greg, and Viger, R.J., 2005, Modeling ground-water recharge from precipitation?development and implementation of the GSFLOW model: Geological Society of America Abstracts with Programs , v. 37, no. 7, p. 30.
  6. Regan, R.S., and Schaffranek, R.W., 1985, A Computer Program for Analyzing Channel Geometry: U.S. Geological Survey Water-Resources Investigations Report 85-4335, 49 p.
  7. Regan, R.S., Schaffranek, R.W., and Baltzer, R.A., 1996, Time-Dependent Data System (TDDS)?An Interactive Program to Assemble, Manage, and Appraise Input Data and Numerical Output of Flow/Transport Simulation Models: U.S. Geological Survey Water-Resources Investigations Report 96-4143, 104 p.

Science and Products

Publications

Filter Total Items: 14
[title_1]
Year Published: 2015

Documentation of a restart option for the U.S. Geological Survey coupled Groundwater and Surface-Water Flow (GSFLOW) model

A new option to write and read antecedent conditions (also referred to as initial conditions) has been developed for the U.S. Geological Survey (USGS) Groundwater and Surface-Water Flow (GSFLOW) numerical, hydrologic simulation code. GSFLOW is an integration of the USGS Precipitation-Runoff Modeling System (PRMS) and USGS Modular Groundwater-Flow Model (MODFLOW), and provides three simulation...

Regan, Robert S.; Niswonger, Richard G.; Markstrom, Steven L.; Barlow, Paul M.
Regan, R.S., Niswonger, R.G., Markstrom, S.L., and Barlow, P.M., 2015, Documentation of a restart option for the U.S. Geological Survey coupled groundwater and surface-water flow (GSFLOW) model: U.S. Geological Survey Techniques and Methods, book 6, chap. D3, 19 p., http://dx.doi.org/10.3133/tm6D3.
[title_1]
Year Published: 2015

Water-budgets and recharge-area simulations for the Spring Creek and Nittany Creek Basins and parts of the Spruce Creek Basin, Centre and Huntingdon Counties, Pennsylvania, Water Years 2000–06

This report describes the results of a study by the U.S. Geological Survey in cooperation with ClearWater Conservancy and the Pennsylvania Department of Environmental Protection to develop a hydrologic model to simulate a water budget and identify areas of greater than average recharge for the Spring Creek Basin in central Pennsylvania. The model was developed to help policy makers, natural...

Fulton, John W.; Risser, Dennis W.; Regan, Robert S.; Walker, John F.; Hunt, Randall J.; Niswonger, Richard G.; Hoffman, Scott A.; Markstrom, Steven
Fulton, J.W., Risser, D.W., Regan, R.S., Walker, J.F., Hunt, R.J., Niswonger, R.G., Hoffman, S.A., and Markstrom, S.L., 2015, Water-budgets and recharge-area simulations for the Spring Creek and Nittany Creek Basins and parts of the Spruce Creek Basin, Centre and Huntingdon Counties, Pennsylvania, Water Years 2000–06: U.S. Geological Survey Scientific Investigations Report 2015–5073, 86 p, http://dx.doi.org/10.3133/sir20155073.
[title_1]
Year Published: 2015

PRMS-IV, the precipitation-runoff modeling system, version 4

Computer models that simulate the hydrologic cycle at a watershed scale facilitate assessment of variability in climate, biota, geology, and human activities on water availability and flow. This report describes an updated version of the Precipitation-Runoff Modeling System. The Precipitation-Runoff Modeling System is a deterministic, distributed-parameter, physical-process-based modeling system...

Markstrom, Steven L.; Regan, Robert S.; Hay, Lauren E.; Viger, Roland J.; Webb, Richard M.; Payn, Robert A.; LaFontaine, Jacob H.
Markstrom, S.L., Regan, R.S., Hay, L.E., Viger, R.J., Webb, R.M.T., Payn, R.A., and LaFontaine, J.H., 2015, PRMS-IV, the precipitation-runoff modeling system, version 4: U.S. Geological Survey Techniques and Methods, book 6, chap. B7, 158 p., http://dx.doi.org/10.3133/tm6B7.
[title_1]
Year Published: 2013

Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin

Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, Robert S.
Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin; 2013; SIR; 2013-5159; Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, Robert S.
[title_1]
Year Published: 2013

Application of the Precipitation-Runoff Modeling System (PRMS) in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States

LaFontaine, Jacob H.; Hay, Lauren E.; Viger, Roland J.; Markstrom, Steve L.; Regan, R. Steve; Elliott, Caroline M.; Jones, John W.
Application of the Precipitation-Runoff Modeling System (PRMS) in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States; 2013; SIR; 2013-5162; LaFontaine, Jacob H.; Hay, Lauren E.; Viger, Roland J.; Markstrom, Steve L.; Regan, R. Steve; Elliott, Caroline M.; Jones, John W.
[title_1]
Year Published: 2013

CRT--Cascade Routing Tool to define and visualize flow paths for grid-based watershed models

Henson, Wesley R.; Medina, Rose L.; Mayers, C. Justin; Niswonger, Richard G.; Regan, R.S.
CRT--Cascade Routing Tool to define and visualize flow paths for grid-based watershed models; 2013; TM; 6-D2; Section D: Ground-Water/Surface-Water in Book 6: <i>Modeling Techniques</i>; Henson, Wesley R.; Medina, Rose L.; Mayers, C. Justin; Niswonger, Richard G.; Regan, R. S.
[title_1]
Year Published: 2012

Watershed scale response to climate change--Sagehen Creek Basin, California

Markstrom, Steven L.; Hay, Lauren E.; Regan, R. Steven
Watershed scale response to climate change--Sagehen Creek Basin, California; 2012; FS; 2011-3121; Markstrom, Steven L.; Hay, Lauren E.; Regan, R. Steven
[title_1]
Year Published: 2012

Integrated watershed-scale response to climate change for selected basins across the United States

Markstrom, Steven L.; Hay, Lauren E.; Ward-Garrison, D. Christian; Risley, John C.; Battaglin, William A.; Bjerklie, David M.; Chase, Katherine J.; Christiansen, Daniel E.; Dudley, Robert W.; Hunt, Randall J.; Koczot, Kathryn M.; Mastin, Mark C.; Regan, R. Steven; Viger, Roland J.; Vining, Kevin C.; Walker, John F.
Integrated watershed-scale response to climate change for selected basins across the United States; 2012; SIR; 2011-5077; Markstrom, Steven L.; Hay, Lauren E.; Ward-Garrison, D. Christian; Risley, John C.; Battaglin, William A.; Bjerklie, David M.; Chase, Katherine J.; Christiansen, Daniel E.; Dudley, Robert W.; Hunt, Randall J.; Koczot, Kathryn M.; Mastin, Mark C.; Regan, R. Steven; Viger, Roland J.; Vining, Kevin C.; Walker, John F.
[title_1]
Year Published: 2011

Decoupled application of the integrated hydrologic model, GSFLOW, to estimate agricultural irrigation in the Santa Rosa Plain, California

Hevesi, Joseph A.; Woolfenden, Linda R.; Niswonger, Richard G.; Regan, R. Steven; Nishikawa, Tracy
[title_1]
Year Published: 2010

Simulation of Runoff and Reservoir Inflow for Use in a Flood-Analysis Model for the Delaware River, Pennsylvania, New Jersey, and New York, 2004-2006

Goode, Daniel J.; Koerkle, Edward H.; Hoffman, Scott A.; Regan, R. Steve; Hay, Lauren E.; Markstrom, Steven L.
Simulation of Runoff and Reservoir Inflow for Use in a Flood-Analysis Model for the Delaware River, Pennsylvania, New Jersey, and New York, 2004-2006; 2010; OFR; 2010-1014; Goode, Daniel J.; Koerkle, Edward H.; Hoffman, Scott A.; Regan, R. Steve; Hay, Lauren E.; Markstrom, Steven L.
[title_1]
Year Published: 2008

GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005)

Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.
GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005); 2008; TM; 6-D1; Chapter 1 of Section D, Ground-Water/Surface-Water of Book 6, Modeling Techniques; Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.
[title_1]
Year Published: 2006

Documentation of the Unsaturated-Zone Flow (UZF1) Package for modeling Unsaturated Flow Between the Land Surface and the Water Table with MODFLOW-2005

Niswonger, Richard G.; Prudic, David E.; Regan, R. Steven
Documentation of the Unsaturated-Zone Flow (UZF1) Package for modeling Unsaturated Flow Between the Land Surface and the Water Table with MODFLOW-2005; 2006; TM; 6-A19; Niswonger, Richard G.; Prudic, David E.; Regan, R. Steven