WMG WMI Coupling a soil hydrology model (SWAP) and a grassland productivity model
The model combination SWAP-WOFOST is suitable for arable crops but not for grassland. Since grass is a major crop, there is a need to couple a grass growth model and a soil water balance model. In this project we will couple an existing Wageningen grassland model LINGRA to SWAP.
More and more there is a need to make good quality prediction of crop production as influenced by weather, climate changes, and to investigate the effects of climate and soil-water dynamics on possible yield reductions. The Wageningen models WOFOST, SWAP and their combination offer possibilities to investigate this. WOFOST is primarily focussed on arable crops. So, grassland production is not covered, whereas this is a major crop in many countries serving as feed for animals. In a previous investment project it was concluded that the dynamics of grass are considerably different from arable crops with a fixed growth cycle as implemented in the WOFOST model. Therefore, it was concluded that the concepts implemented in WOFOST are not easily extended to grasslands. Instead, it was suggested to take one of the existing and validated Wageningen models for grassland.
This project will choose one of these and create an environment in which test sets are created to verify its use either as original model, a newly Python implemented version and an newly implemented Fortran90 version coupled or integrated in the SWAP model. These activities will follow the same procedure as recently developed for testing the WOFOST implementation in Python and the Fortran90 version as integrated in SWAP. At the end of the project we expect that next to arable crops we can consider grass production as well.