The model is based on two artificial compartments for agriculture and nature, an driven by scenarios for climate change, land use and crop schemes. Water levels in the agriculture and nature compartment are optimized based on monthly target levels and day-to-day decisions on water management actions such as canal intake, sea discharge and creek ridge extraction or infiltration. The model uses a time horizon of 80 years (2020-2100) and a time step of 1 day, to align with the practice of water management decisions (such as the opening of sluices). It has been organised around 12 modules or VenSim ‘views’, including a policy dashboard showing key indicators related to drought and flooding of the compartments.
The model uses diverse data related to land use cover change, climate change, meteorology, water management, and crop farming. Important data sources include: the Royal Meteorological Institute (KMI) of Belgium for meteorological parameters, FAO (crop factors) and the Flemish Land Agency (for water control parameters). Operational water management parameters such as desired levels and thresholds for gravitational sea discharge were discussed with and provided by the Flemish Land Agency. Driving scenarios are based on the Shared-Social Economic Pathways (for crop schemes and land use patterns, see https://doi.org/10.5281/zenodo.7081500 ), the VITO RuimteModel for land use change (see https://vito.be/en/product/geodynamix-spatial-modelling-tools), RCP-based projections for temperature, potential evapotranpiration and precipitation, and related sea level projections obtained from Fox-Kemper, B., et al., 2021, Ocean, Cryosphere and Sea Level Change. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (Masson-Delmotte, V., P., et al. (eds.)). Cambridge University Press. In Press.
IMPORTANT: although basic hydrological principles are respected the model is still under development and a groundwater module is needed to ensure the model will replicate the behavior of the real water system correctly. It should be emphasized that the model is, ultimately, designed to be complementary to operational hydrological models. A correctly functioning hydrological model core is essential for further development of the model to include more social and environmental factors such as food production, CO2 capture, rural gentrification and ecosystem services in a fully dynamic manner while consideration system feedback, dynamic threshold and system tipping points, the main assets of SD modelling.
The model was developed with the VenSim PLP software. It cannot be used with free VenSim PLE license due to the use of external data (xls).
For further information on VenSim see https://vensim.com/