Gao et al. (2026) Physical continuous-simulation SWAT + framework to develop flow duration curves within the contiguous United States

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-08-19
• Authors: Jungang Gao, Natalja Čerkasova, Michael J. White, Peter Allen, Jeffrey G. Arnold, Katrin Bieger, Mazdak Arabi, Ryan Bailey
• DOI: 10.1016/j.jhydrol.2026.136278

Research Groups

• Blackland Research & Extension Center, Texas A&M AgriLife
• Agricultural Research Service, US Department of Agriculture (USDA)
• Baylor University, Department of Geology
• Aarhus University, Department of Ecoscience
• Colorado State University, Civil and Environmental Engineering
• Klaipeda University, Marine Research Institute

Short Summary

This study implements a SWAT+ framework to predict Flow Duration Curves (FDCs) across the contiguous United States (CONUS), providing a tool to characterize streamflow regimes and watershed performance.

Objective

• To predict FDCs using a continuous simulation daily time step model calibrated to mean annual flow for the contiguous United States (CONUS).

Study Configuration

• Spatial Scale: Contiguous United States (CONUS), with outputs compiled by NHDPlus reach.
• Temporal Scale: Continuous simulation with a daily time step.

Methodology and Data

• Models used: SWAT+ (Soil and Water Assessment Tool Plus).
• Data sources: Long-term USGS streamflow records (from relatively undisturbed gages) and NHDPlus data.

Main Results

• The model demonstrated the ability to simulate various flow regimes with the following average Nash-Sutcliffe Efficiency (NSE) values:
  • High flows: 0.69
  • Medium flows: 0.84
  • Low flows: 0.56

Contributions

• This research represents a novel effort to predict FDCs at a national scale (CONUS) using a continuous simulation model. Unlike static historical data, this approach allows for the simulation of diverse climate and land-use scenarios.

Funding

• Not specified in the provided text.

Citation

@article{Gao2026Physical,
  author = {Gao, Jungang and Čerkasova, Natalja and White, Michael J. and Allen, Peter and Arnold, Jeffrey G. and Bieger, Katrin and Arabi, Mazdak and Bailey, Ryan},
  title = {Physical continuous-simulation SWAT + framework to develop flow duration curves within the contiguous United States},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136278},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136278}
}