Non-spatial model to simulate semi-arid vegetation-soil systems
This is a lumped (non-spatial) model simulating plant growth coupled to erosion processes in semi-arid vegetation-soil systems. The equations of the model are described in Karssenberg, D., Bierkens, M.F.P., Rietkerk, M. (2017), Catastrophic Shifts in Semiarid Vegetation-Soil Systems May Unfold Rapidly or Slowly, https://doi.org/10.1086/694413.
The model uses components from the PCRaster Python framework and you need to install PCRaster to run the model, https://www.pcraster.eu
main.py Contains the model. It is written in the PCRaster Python framework. See http://www.pcraster.eu. The model writes two files with output timeseries for biomass and regolith thickness. It also writes the grazing pressure.
parameters.py Contains the parameters. These need to be varied to get different realizations of the 'reality'. See the article for the explanation of the parameters. The parameter values in the file correspond to those in the article and settings for some of the scenarios are provided.
plot.py Script to plot the timeseries. Output is timeseries.pdf