Admas et al. (2026) Calibration and validation strategies of SWAT+ for streamflow simulation: a systematic review

Identification

• Journal: Frontiers in Water
• Year: 2026
• Date: 2026-09-08
• Authors: Betelhem Fetene Admas, Temesgen Gashaw, Raghavan Srinivasan, Daniel Valadão Silva, Rafael Leandro Fernandes Melo, Frederico Ribeiro do Carmo
• DOI: 10.3389/frwa.2026.1882804

Research Groups

• Postgraduate Program in Soil and Water Management, Department of Agrarian Sciences, Federal Rural University of the Semi-Arid Region, Mossoró, Rio Grande do Norte, Brazil
• Department of Natural Resource Management, College of Agriculture and Environmental Sciences, University of Gondar, Gondar, Ethiopia
• College of Agriculture, Food and Natural Resources, Prairie View A&M University, Prairie View, TX, United States
• Department of Natural Resource Management, College of Agriculture and Environmental Sciences, Bahir Dar University, Bahir Dar, Ethiopia
• College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
• Federal Institute of Education, Science and Technology of Ceará, Tabuleiro do Norte Campus, Ceará, Brazil

Short Summary

This systematic review evaluates the calibration and validation strategies used in SWAT+ streamflow simulation studies. The study identifies the most effective data sources, calibration tools and software, and methodological approaches used in SWAT+ modeling.

Objective

• To systematically identify the main and alternative input data sources, calibration datasets, calibration and validation software/tools, and recent advances in calibration approaches for SWAT+ streamflow simulation

Study Configuration

• Spatial Scale: Watersheds of varying sizes, from small to large river basins
• Temporal Scale: Daily, monthly, and annual time steps

Methodology and Data

• Models used: Soil and Water Assessment Tool Plus (SWAT+)
• Data sources:
  • Digital elevation model (DEM) datasets
  • Land use/land cover (LULC) datasets
  • Soil datasets
  • Climate data from ground-based weather stations, gridded climate products, and global climate models

Main Results

• The study found that the SWAT+ Toolbox with Dynamically Dimensioned Search (DDS) algorithm was the most widely used calibration software due to its accessibility and integrated optimization algorithms.
• Hybrid calibration approaches integrating automatic optimization with subsequent manual refinement consistently improved parameterization.
• Multi-site and multi-variable calibration using actual evapotranspiration (ETa) or soil moisture reduced parameter equifinality in heterogeneous watersheds.

Contributions

• The study provides a comprehensive review of the current state of SWAT+ streamflow simulation studies, highlighting the most effective data sources, calibration tools and software, and methodological approaches used.
• The findings can be used to inform future research and improve the reproducibility and accuracy of SWAT+ simulations.

Funding

• This systematic review was funded by various projects, programs, and reference codes, including:
  • Postgraduate Program in Soil and Water Management, Federal Rural University of the Semi-Arid Region
  • Department of Natural Resource Management, College of Agriculture and Environmental Sciences, University of Gondar
  • College of Agriculture, Food and Natural Resources, Prairie View A&M University

Citation

@article{Admas2026Calibration,
  author = {Admas, Betelhem Fetene and Gashaw, Temesgen and Srinivasan, Raghavan and Silva, Daniel Valadão and Melo, Rafael Leandro Fernandes and Carmo, Frederico Ribeiro do},
  title = {Calibration and validation strategies of SWAT+ for streamflow simulation: a systematic review},
  journal = {Frontiers in Water},
  year = {2026},
  doi = {10.3389/frwa.2026.1882804},
  url = {https://doi.org/10.3389/frwa.2026.1882804}
}