Poster Presentation Society for Freshwater Science 2025 Annual Meeting

What is a headwater? Exploring emergent archetypes of headwater catchments across the United States. (118212)

Erin C. Seybold 1 , Margaret Zimmer 2 , Jay Christensen 3 , John Hammond 4 , Charles Lane 3 , Nate Jones 5 , Adam Price 6 , Christa Kelleher 7 , Catalina Segura 8 , Admin Husic 9 , Li Li 10 , Heather Golden 3 , Hilary McMillan 11 , Kris Jaeger 12 , Tyler Mahoney 13 , Fred Cheng 14 , Roy Sando 15 , Adam Ward 8
  1. Kansas Geological Survey/Department of Geology, University of Kansas, KS, United States
  2. University of Wisconsin, Madison, WI
  3. US EPA, Cincinnati , Ohio
  4. U.S. Geological Survey, Catonsville, Maryland
  5. University of Alabama, Tuscaloosa, AL
  6. U.S. Forest Service, La Grande, OR
  7. Lafayette College, Easton, PA
  8. Oregon State University, Corvallis, OR
  9. Virginia Tech, Blacksburg, VA
  10. Penn State University, State College, PA
  11. San Diego State University, San Diego, CA
  12. U.S. Geological Survey, Tacoma, WA
  13. University of Louisville, Louisville, KY
  14. University of Virginia, Charlottesville, VA
  15. U.S. Geological Survey, Helena, MT

Headwater watersheds provide essential ecosystem services, but are increasingly imperiled by a lack of legal protections. In order to protect and manage these vital systems, it is imperative we further our scientific understanding of headwater characteristics across diverse regions, particularly because limited data exist outside of well-instrumented small catchment research sites. In this study, we compare headwater characteristics (defined from basins draining NHDPlus-High Resolution stream order 1 and 2) from watersheds across the United States to understand how headwater watershed attributes vary regionally, and contrast them with attributes of downstream receiving systems (defined as basins draining stream order 3 and greater) to understand unique traits of headwater systems. We find key differences in headwater structures and traits that vary regionally, with likely impacts on hydrologic function and connection to downstream waters. These data-driven, emergent archetypes of headwaters help expand our conceptual understanding of what defines a headwater watershed, and highlight the need for model development and monitoring that can represent these distinct systems.