The Tennessee River Basin in the southeastern United States is the most intensively used freshwater water resource region in the contiguous United States, supporting approximately 4.5 million people with estimated withdrawals of more than 280,000 gallons per day per square mile.
Water resources in the Tennessee River Basin and broader southeastern region are vulnerable to changes in land use and land cover and a range of climate-induced disturbances. Projections indicate that the southeastern United States will experience higher temperatures, more extreme heat events, and an intensifying hydrologic cycle with more frequent and severe storm and drought events over time.
To address these changes, the Watershed Dynamics and Evolution (WaDE) Science Focus Area (SFA) at the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) will advance predictive understanding of how dominant processes controlling watershed hydro-biogeochemical function operate under a range of hydrologic regimes and vary along stream networks that drain heterogeneous land covers.
To advance watershed science, it is necessary to develop a systematic framework that explicitly links local physical–chemical–biological heterogeneity to larger spatial organization. Research efforts over the next 9 years will be on three watersheds, studied in succession, with the goal of systematically translating, applying, and refining the process understanding and modeling capabilities we gain from a specific watershed to increasingly disparate systems. All three watersheds will be of similar mid-order size, with heterogeneous land cover, and located in areas experiencing rapid land cover change within the Tennessee River Basin.
The WaDE SFA is organized around three integrated research themes and a crosscutting modeling activity that together create a multiscale, model–observation–experiment framework to enable hypothesis-driven research addressing the knowledge gaps. Collectively, this framework will advance a deeper, predictive understanding of the hydro-biogeochemical processes and feedbacks that control solute mobilization and export from headwater catchments with heterogeneous land cover (Theme 1), resultant feedbacks between flow, solute concentrations, and stream function in stream corridors (Theme 2), and the emergent patterns in stream metabolism at network scales (Theme 3).
- Theme 1: Dynamic Headwaters
- Theme 2: Stream Corridor Processes
- Theme 3: Network Function
- Modeling Crosscut: Virtual Watershed
To learn more, visit https://wade.ornl.gov/.