Sean Smith

Sen. George J. Mitchell Center for Sustainability Solutions | MAFES | NEST

Research Focus and History Courses | Graduate Advising

I lead the Watershed Process and Sustainability Research Group (WPS) in the School of Earth and Climate Sciences. WPS is involved in multiple research projects, including several multi-institutional projects administered by the Sen. George J. Mitchell Center for Sustainability Solutions.


Congratulations to Brett Gerard for completing his doctoral dissertation on STREAM DYNAMICS IN THE HEADWATERS OF POST-GLACIAL WATERSHED SYSTEMS and to Nicholas Richmond for his master’s thesis on THREE-DIMENSIONAL BEDROCK CHANNEL EVOLUTION WITH SMOOTHED PARTICLE HYDRODYNAMICS (December 2018). Both of the efforts have produced intriguing and useful information that will help with complicated river management decisions in New England and the development of watershed sustainability solutions in Maine. Way to go Brett and Nicholas!!

Coastal Pollution Research Grant awarded (Spring 2018) WPS has been awarded a new grant from the Maine Water Resources Research Institute to conduct research  for development of decision tools related to coastal bacteria pollution. The project builds on previous research led by the Mitchell Center focused on the scientific basis for decisions governing closures of shellfish harvesting areas and beaches in response to bacteria pollution problems.  The new work will focus on margin watershed areas (shaded purple in figure at right) and estuaries on the Maine coast. 


Penobscot Float Trip video published by UMaine Today magazine highlights activities during our fall semester (2016) float down the section of the Penobscot River near campus. 










Article by Buscombe, Grams, and Smith selected as 2017 Best Technical Note by the editor of the Journal of Hydraulic Engineering.

WPS research group is highlighted in UMaine Today magazine article focused on a century of research in Acadia National Park umaine-today_a-century-in-acadia

WPS affiliates are included in UMaine Today article, A Century in Acadia, The Symbiosis Between a National Park and Maine’s Public Research University. A companion article is included in the special online edition of the magazine that highlights WPS research on coupled coastal watershed-estuary systems. The National Science Foundation-supported project is led by the Sen. George J. Mitchell Center for Sustainability Solutions and focused on non-point source pollution affecting the coast of Maine.

WPS research group members share 2016 Mitchell Center award

Members of WPS received an award for an “outstanding contribution toward the development of a solution by a research team” from the Sen. George J. Mitchell Center. The award recognizes contributions to the NEST – Safe Beaches and Shellfish Areas project by Sam Roy and Brett Gerard.

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Research team uses Storms in Wells Maine to gain Insight on Rainfall and Water Quality Patterns  10/6/16

Rising to the Surface for Sustainability Solutions  highlights WPS affiliate, Samuel Roy (2016)

Reds Wolman Stream DedicationThe Baltimore Sun recently published an Article about M.G. “Reds” Wolman and the effort to rename a portion of stream in Maryland after him.

20160811_133210b“Job Well Done” to Caroline Carrigan who wrapped up her summer research project focused on coastal watershed erosion with the Sea Fellows program at the Darling Marine Center. Way to go Caroline!



Maine Cooperative Snow Survey Program  welcomes WPS participation (2/1/16)

Two contrasting views of stream sediment sources. McGlaughlin 2015. Environmental Connection (International Erosion Control Assn.), Vol. 9, Issue 3, pp. 8-9.

Scientists develop new tools to anticipate coastal pollution in Maine  AGU Geospace Blogosphere (12/30/15)

The Future of Dams: new $6 million NSF grant. University of Maine News (8/10/15)

Student Research Spotlight: Looking for Warning Signs Beneath the Surface, Sen. George J. Mitchell Center News (2/18/15)

Publication finds upland sources contribute to sediment loads, Sen. George J. Mitchell Center News (1/29/15)

Researchers raft down Penobscot River to map changes, Aislinn Sarnacki, Bangor Daily News (6/25/14)

Poster Session Honorable Mention at Maine Sustainability and Water Conference:  Van Dam, B,  S. Smith, A. Reeve, B. Gerard. Hydrologic Implications of Upland Microtopography in Post-Glaciated Maine 

Research Focus and History

My teaching and research focuses on watershed geomorphology with attention to processes that influence the morphology and stability of hillslopes and waterways, and that govern the flux of water, sediment and nutrients in the contemporary landscape. Topics of my past and present research include stream channel morphology and stability, surface flow patterns in headwater drainage basins, watershed sediment budgets, and modern watershed best management and rehabilitation practices. I am particularly interested in projects seeking to identify, quantify and explain changes to landscapes caused by human activities.

My work is inspired by interests in advancing the measurement, description and prediction of environmental impacts across spatial scales ranging from single hillslopes to large watersheds and time scales spanning from a single rainfall event to millennia. I have extensive experience working in the Mid-Atlantic region of North America in collaboration with partners involved with the USEPA Chesapeake Bay Program. I have a joint appointment with the Senator George J. Mitchell Center for Sustainability Solutions and affiliation with the Maine Agricultural and Forest Experiment Station (MAFES).

Interdisciplinary projects:

These projects involve faculty, post-doctoral researchers, graduate students, and undergraduate research assistants that comprise the School of Earth and Climate Science’s Watershed Process and Sustainability Research Group working in collaboration with multiple colleagues, government agencies, and project stakeholders in Maine and beyond.

Example WPS research questions: 

  • What do headwater streams in Maine look like and how do they change over time?
  • Where do streams in coastal Maine watersheds begin?
  • How do coastal watersheds respond to rainfall and what landscape characteristics influence pollutant delivery to lakes and tidal estuaries?


ERS 200 – Earth Systems

ERS 350 – Freshwater Flows

ERS 588 – Advanced Freshwater Flows

ERS 361 – Principles of Geomorphology

ERS 461 – Fluvial Processes in Geomorphology

ERS 602 – Critical Zone and Watershed Sustainability Research

Graduate Advising



Bea Van Dam – M.S. Student, Land-sea connections driving coastal pollution vulnerability

Andrew Newcomb – M.S.  Student, Future of dams in New England

Ian Nesbit – M.S. Student, Maine lake sedimentation

Hannah Horecka – M.S. Student, Coastal pollution dynamics


Brett Gerard – Ph.D., 2018, Channel bed dynamics in a coupled human-climate-postglacial system



Nick Richmond, Ph.D. Student – River channel evolution with smooth particle hydrodynamics, School of Earth and Climate Sciences

Fuyu Xi – Ph.D. Student, Spatial temporal event sequence similarity analysis for ecological applications, School of Computing and Information Science

Iman Shakib, Ph.D. Student – Future of Dams in New England, Department of Civil Engineering, Univ. of New Hampshire

Prashanta Bajracharya, M.S. Student – Hydrodynamic modeling with attention to natural infrastructure in Maine’s Watersheds, Department of Civil and Environmental Engineering


David Simon – M.S., 2018, Quantifying the impact of dams on floods and nitrogen flux in the Lamprey River watershed, NH, Earth Sciences, Univ. of New Hampshire

Kaci Fitzgibbon – M.S., 2017, Maine lake vulnerability to nutrient pollution, School of Earth and Climate Sciences

Chris Dorr – Ph.D., 2017, Qualitative shape descriptions using qualitative spatial calculi, School of Computing and Information Science

Catherine Johnston – M.S., 2016, The potential for shortnose sturgeon spawning in the Penobscot River, School of Marine Sciences

Jarrod Cicha – M.S., 2015, Temperature as a proxy to study the flow of water within two Maine streambeds, School of Earth and Climate sciences

Samuel Roy – Ph.D., 2015, Silicate earth circulation modeling, School of Earth and Climate Sciences

Thomas Parr – Ph.D., 2014. Human landscapes driving biogeochemistry, School of Biology and Ecology

Christiaan Bon – M.S., 2013, Peatland carbon flux, School of Earth and Climate Sciences

Publications, Reports, and Professional Activities

Peer Reviewed Publications

  • Johnston, C., G.B. Zydlewski, S. Smith, J. Zydlewski, and M.T. Kinnison. 2019. River reach restored by dam removal offers suitable spawning habitat for endangered shortnose sturgeon. Transactions of the American Fisheries Society, Vol. 148, Issue 1, pp. 163-175; DOI: 10.1002/tafs.10126
  • Roy, S.G., E. Uchidab, S.P. de Souzac, B. Blachly, E. Fox, K. Gardner, A.J. Gold, J. Jansujwicz, S. Klein, B. McGreavy, W. Moc, S.M.C. Smith, E. Vogleri, K. Wilson, J. Zydlewskik, and D. Hart. 2018. Damming decisions: a multi-scale approach to balance trade-offs among dam infrastructure, river restoration, and cost. Proceedings of the National Academy of Sciences Nov 2018, Vol. 115, No. 47, pp. 12069-12074; DOI:10.1073/pnas.1807437115
  • Roy, S., G. Tucker, P. Koons, S. Smith, and P. Upton. 2016. A fault runs through it: modeling the influence of rock strength and grain-size distribution in a fault-damaged landscape. Journal of Geophysical Research, Vol. 121, I. 10, pp. 1911–1930,   doi: 10.1002/2015JF003662
  • Buscombe, D., P.E. Grams, S.M.C. Smith. 2015. Automated riverbed sediment classification using low cost side-scan sonar. Journal of Hydraulic Engineering, doi:  10.1061/(ASCE)HY.1943-7900.0001079 , 06015019.
  • Filoso, S., S.M.C. Smith, M.R. Williams, and M.A. Palmer. 2015. The Efficacy of Constructed Stream–Wetland Complexes at Reducing the Flux of Suspended Solids to Chesapeake Bay. Environmental Science and Technology, Vol. 49, No. 15, pp. 8986–8994. doi: 10.1021/acs.est.5b00063
  • Buscombe, D., P.E. Grams, T.S. Melis, and S.M.C. Smith. 2015. Large river bed sediment characterization with low-cost sidescan sonar: case studies from two settings in the Colorado (Arizona) and Penobscot (Maine) Rivers. SEDHYD 2015, 3rd Joint Federal Interagency Conference (10th Federal Interagency Sedimentation Conference and 5th Federal Interagency Hydrologic Modeling Conference.
  • Smith, S.M.C. and P.R. Wilcock. 2015. Upland Sediment Supply and its Relation to Watershed Sediment Delivery in the Contemporary Mid-Atlantic Piedmont (U.S.A.), Geomorphology, Vol. 232, pp. 33-46,
  • Parr, T.B., C.S. Cronin, T. Ohno, S.E.G. Findlay, S.M.C. Smith, and K.S. Simon. 2015. Urbanization changes the composition and bioavailability of dissolved organic matter in headwater streams. Limnology and Oceanography, Vol. 60, Issue 3, pp. 885-900, doi: 10.1002/lno.10060
  • Peckenham, J., D. Hart, S. Smith, and S. Jain. 2012. The path to water resources solutions. Maine Policy Review Water Resources SSI V7 2/24/12
  • Smith, S.M.C., P. Belmont, and P.R. Wilcock. 2011. Closing the gap between sediment budgeting, watershed modeling and stream restoration. In:  Simon, A., S.J. Bennett, and J.M. Castro (Eds.). Stream Restoration in Dynamic Systems: Scientific Approaches, Analyses, and Tools. Water Resources Monograph. American Geophys. Union.Washington, D.C.
  • Bain, D.J., S.M.C. Smith, and G.N. Nagle. 2008. Reservations about dam findings. Science, Vol. 321. No. 5891, p. 910, doi: 10.1126/science.321.5891.910a
  • Craig, L.S., D.C. Richardson, M. Palmer, E. Bernhardt, B. Bledsoe, M. Doyle, B. Hassett, S. Kaushal, S. Smith, and P. Wilcock. 2008. Stream restoration strategies for reducing river nitrogen loads. Frontiers in Ecology and the Environment. doi:  10.1890/070080.
  • Smith, S. 2006. Chesapeake Bay. In:  Trimble, S. (Ed). Encyclopedia of Water Science. Taylor and Francis Reference Group, LLC. New York.
  • Smith, S. and K.L. Prestegaard. 2005. Hydraulic performance of a morphology based stream channel design. Water Resources Research, Vol. 41, W11413, doi:10.1029/2004WR003926.
  • Hassett, B., M. Palmer, E. Bernhardt, S. Smith, J. Carr, and D. Hart. 2005. Restoring watersheds project by project: trends in Chesapeake Bay tributary restoration. Frontiers in Ecology and the Environment. Vol. 3, No. 5, pp. 259–267.
  • Gellis, A., S. Smith, and S. Stewart. 2003. Watershed sediment sources, Chapter 2. In:  Langland, M. and T. Cronin (Eds). A summary report of sediment processes in Chesapeake Bay and watershed. USGS Water Res. Invest. Report 03-4123.
  • Smith, S., M. Langland, and R. Edwards. 2003. Watershed sediment transport, Chapter 3. In:  Langland, M. and T. Cronin (Eds). A summary report of sediment processes in Chesapeake Bay and watershed. USGS Water Resources Investigations Report 03-4123.
  • Smith, S., J. Herman, T. Cronin, G. Schwarz, M. Landland, K. Patison, and L. Linker. 2003. Integrated approaches to sediment studies, Chapter 7. In:  Langland, M. and T. Cronin (Eds). A summary report of sediment processes in Chesapeake Bay and watershed. USGS Water Resources Investigations Report 03-4123.

Education Publications

  • Smith, S., L. Gutierrez, and A. Gagnon. 2000. Maryland Streams – Take a Closer Look. Watershed Restoration Division, Maryland Department of Natural Resources. Reprinted 2003, 2005, 2009.

Recent Presentations

  • Skalak, K., J.E. Pizzuto, D.L. Karwan, S. Mahan, A. Benthem, E.W. Boyer, A. Kettner, R.K. LeBivic, A.J. Miller, G.B. Noe, and S.M.C. Smith. 2018. Temporal and spatial scales of sediment transport processes for watershed management. Fall Meeting, American Geophysical Union. Washington, D.C.
  • Gerard, B. and S.M.C. Smith. 2018. Stream dynamics in headwaters of postglacial watershed systems. Maine Sustainability and Water Conference, Augusta, Maine.
  • McGreavy, B., S. Randall, T. Quiring, S. Smith, S. Roy, B. Gerard, and C. Hathaway. 2017. Communicating coastal resilience: Interdisciplinary research partnerships to support shellfish management and protect public health. Conference on Communication and Environment, University of Leicester (UK).
  • Smith, S.M.C. 2017. INVITEDWhat is the importance of legacy sediment relative to other sediment sources in the Chesapeake Bay watershed? Chesapeake Bay Program, Science and Technical Advisory Committee workshop on legacy sediment. Annapolis, Maryland.
  • Smith, S.M.C. 2017. INVITED – Examining and communicating coastal pollution problems along the coast of Maine. Northeast Shellfish Sanitation Annual Meeting. Freeport, Maine.
  • Roy, S., B. Gerard, S. Smith, and B. McGreavy. 2017. A runoff based vulnerability analysis to examine the dynamics of bacteria pollution events in the Gulf of Maine. Maine Sustainability and Water Conference. Augusta, Maine.
  • Smith, S. 2017. The ups and downs of simulation watershed processes in the Maine terrain. Maine Association of Professional Soil Scientists – Annual Meeting. Orono, Maine.
  • Smith, S.M.C. 2016. INVITED – Downeast drainage: sources, delivery and residence time of runoff and pollutants along the Gulf of Maine coast. Geological Society of Maine, Fall Meeting. November 21, 2016.
  • Smith, S.M.C. 2016. INVITED – Mentoring through measurement, monitoring and modeling the Penobscot River. Penobscot Watershed Conference:  Sharing our heritage, challenges and future. Lincolville, Maine. April 2016.
  • Smith, S.M.C., S. Roy, and B. McGreavy. 2016. Preliminary results from the NEST Safe Beaches and Shellfish Areas project. Presentation to the Maine Shellfish Advisory Council. 11/29/16 Ellsworth, Maine.
  • Gerard, B., S.M.C. Smith, A. Sivitskis, A.S. Reeve, and B.M. Van Dam. 2015. Human modifications and watershed hydrologic processes in a postglacial landscape. Joint Assembly of the American Geophysical Union, GAC, MAC, and CGU. Montreal, Canada.
  • Johnston, C., G. Zydlewski, J. Zydlewski, M. Kinnison, S. Smith. 2015. What is the spawning potential for shortnose sturgeon (Acipenser brevirostrum) in the Penobscot River after dam removal? An acoustic telemetry and habitat suitability study. Annual Meeting of the American Fisheries Society. Portland, Oregon.
  • Smith, S.M.C. 2014. Present day stream conditions. Maryland Stream Information Exchange: Paleo to Present Stream Conditions and Functions. Maryland Department of Natural Resources, Annapolis, Maryland.
  • Filoso, S. and S. Smith. 2013. Physical modifications to Coastal Plain drainage networks and their implications to nutrient and sediment delivery. Geological Society of American, Northeastern Section Annual Meeting. Bretton Woods, New Hampshire.
  • Smith, S.M.C. 2012. Watershed sediment relations in the contemporary Piedmont. Inaugural Mid-Atlantic Conference: Soil to Sea Geomorphology. University of Pennsylvania, Philadelphia Pennsylvania.

Recent Posters

  • Van Dam, B.E., S.M.C. Smith, K. Beard, and S.G. Roy. 2018. Upland Micro-topography and implications to surface water detention in Maine. Fall Meeting, American Geophysical Union. Washington, D.C.
  • Nesbit, I.M., S.W. Campbell, S.A. Arcone, S.M.C. Smith, B.G. Koffman. 2018. Sedimentary architecture and accumulation rates of multiple lakes in New England, USA. Fall Meeting, American Geophysical Union. Washington, D.C.
  • Roy, S.G., S.M.C. Smith, B. McGreavy, B. Gerard, B.E. Van Dam, and J.L. Ross. 2018. Resilient coastal communities: using interdisciplinary research and stakeholder engagement to face coastal pollution challenges in northern New England. Fall Meeting, American Geophysical Union. Washington, D.C.
  • Neptune, S., S. Roy, and S.M.C. Smith. 2018. Flooded corridors and the inundation of a nation. Maine Sustainability and Water Conference, Augusta, Maine.
  • Richmond, N., P. Koons, L. Ross, S. Smith, S. Roy, G. Zydlewski, and J. Zydlewski. 2018. Post-dam removal river hydraulics and the influence of derelict industrial logging infrastructure on modern aquatic habitat conditions. Maine Sustainability and Water Conference, Augusta, Maine

Recent Technical Reports

  • Gerard, B. and S.M.C. Smith. 2016. Connecting land cover and climate to Sebago Lake drainage network processes. Final report to the Maine Water Resources Research Institute, Grant # G11AP20083, Project # 5406025.