The H2020 OPTAIN project involves both, catchment-, and field-scale modelling of the transport of water and nutrients. The catchment-scale modelling is performed at fourteen case study catchments across Europe using the SWAT+ model. At seven OPTAIN case studies, field-scale modelling is applied using the SWAP model. The aim of the SWAP modelling is to provide data on soil water balance elements using a more detailed (at field-scale) soil hydrological model and to cross-validate this data with the relevant fields in SWAT+. As the official manual from the SWAP model developers is rather detailed and complex, the OPTAIN SWAP modelling protocol focuses on practical issues, without overwhelming the modellers with information unnecessary for their case-studies. It also describes new tools, such as rswap, developed within the OPTAIN project for reference data quality check, model calibration and visualisation of the model results.

Cite as: Farkas, C., Shore, M., Cuceloglu, G., Czelnai, L., Nemes, A., Szabó, B., Čerkasova, N., Idzelyté, R., Weiland, S. (2022): OPTAIN Modelling Protocols. Part 2. SWAP modelling protocol. Deliverable D4.2/b EU Horizon 2020 OPTAIN Project, Grant agreement No. 862756. DOI: 10.5281/zenodo.7907115