Teran et al. (2026) Integrating reservoirs and lakes in the CoSWAT global hydrological model

Identification

• Journal: Geoscientific model development
• Year: 2026
• Date: 2026-07-29
• Authors: Jose P. Teran, Celray James Chawanda, Albert Nkwasa, Inne Vanderkelen, Jeffrey G. Arnold, Ann van Griensven
• DOI: 10.5194/gmd-19-6879-2026

Research Groups

• Department of Water and Climate, Vrije Universiteit Brussel (Belgium)
• Blackland Research & Extension Center, Texas A&M Agrilife Research (USA)
• Water Security Research Group, International Institute for Applied Systems Analysis (IIASA) (Austria)
• Department of Earth and Environmental Sciences, KU Leuven (Belgium)
• Royal Meteorological Institute of Belgium (RMIB) (Belgium)
• Grassland Soil and Water Research Laboratory, USDA Agricultural Research Service (ARS) (USA)
• Institute for Water Education (IHE) Delft (Netherlands)

Short Summary

This study integrates reservoirs and lakes into the CoSWAT global hydrological model, improving its ability to represent basins where these water bodies play a significant hydrological role. The new implementations were applied in selected regions worldwide with sufficient data availability.

Objective

• To develop a robust and flexible algorithm for resolving water areas into the model structure and river network.
• To improve the representation of reservoirs and lakes in the CoSWAT model, combining the strengths of SWAT+ and state-of-the-art schemes used in other global water models.
• To introduce an automatic approach to define irrigation application and demand to irrigation-purpose reservoirs.

Study Configuration

• Spatial Scale: Global, with a spatial input data resolution of 0.01°.
• Temporal Scale: Daily time step for the period 1965–2015, with a 5-year warm-up period.

Methodology and Data

• Models used: SWAT+ (revision 61.0.2) with modifications to integrate decision tables with parametric methods for reservoir-related subroutines.
• Data sources: Global datasets including ASTER GDEM, ESA CCI Land Cover Product, FAO Harmonized World Soil Database, HydroLakes, GranD, and GLOBathy.

Main Results

• The new implementations improved the model's ability to represent reservoir or lake storage, inflows, and outflows.
• The model's streamflow performance with and without the new implementations was compared, showing an improvement in 70% of evaluated stations following the integration of lakes and reservoirs.

Contributions

• This study represents a substantial improvement for the CoSWAT global model, enabling more robust and realistic assessments of inland water systems at the global scale.
• The new algorithm for resolving water areas into the model structure and river network is a significant contribution to the field of global hydrological modeling.

Funding

• Not specified in the provided text.

Citation

@article{Teran2026Integrating,
  author = {Teran, Jose P. and Chawanda, Celray James and Nkwasa, Albert and Vanderkelen, Inne and Arnold, Jeffrey G. and Griensven, Ann van},
  title = {Integrating reservoirs and lakes in the CoSWAT global hydrological model},
  journal = {Geoscientific model development},
  year = {2026},
  doi = {10.5194/gmd-19-6879-2026},
  url = {https://doi.org/10.5194/gmd-19-6879-2026}
}