Example Simulation and Reduced Complexity Models for NetLogo

Online resources for the chapter on Simulation and Reduced Complexity Models in Clifford et al. (2016) Key Methods in Geography

The model code provided here can be run in NetLogo, a programmable environment for agent-based and multi-agent modelling. The NetLogo application can downloaded and installed on your computer to run models offline, or you can run models online via NetLogo Web. To get started with NetLogo, before interacting with the models mentioned in the chapter text, explore the tutorials that are available for NetLogo.

Once you understand the basics of how to interact with NetLogo you can try the models mentioned in the chapter text. First, you will need to download the model code files onto your computer. You can download files individually from the links below (e.g. on Windows right-click then 'Save As'):

• Model 1: SimRed_Model1.nlogo
• Model 2: SimRed_Model2.nlogo
• Model 3: SimRed_Model3.nlogo
• Model 4: SimRed_Model4.nlogo

Alternatively, you can download all model files at once by clicking the green 'Code' button near the top of this page, then Download ZIP, and finally unzip the downloaded file onto your computer.

Second, once you have the model files on your computer, you can explore them by either:

1. opening a model file directly with the NetLogo application (File -> Open)
2. uploading a model file to NetLogo Web (click Browse in top right at)

See the suggested exercises below for ideas on how to explore the models.

Exercises

Model 1

• See how patterns vary for different establishment rules and random number generator seeds (i.e., different values of the rand-seed slider).

Model 2

• Vary values of the rainfall-rate and plant-water-req sliders to examine the influence on number and patterns of plants that grow and spread.
• Vary the establishment option to see how this influences patterns of vegetation. For which option do you see fewer (but larger) clusters of vegetation?
• Use the rand-seed slider to enable consistent comparisons.

Model 3

• Examine combinations of p-dep, wind-strength and initial-depth to see how different forms (spatial patterns of heights of sand) vary over time (>50,000 ticks).
• Also, examine how patterns differ for different wind-direction.

Model 4

• Try changing the log-alpha value (producing different values for alpha, the memory parameter) to change the TSF Curve and the ignition-rate value to change the number of ignitions per timestep.
• Look at how these changes influence the size of fires and how restricted they are by patterns of vegetation.