Basic Cellular Automata

The Basic Cellular Automata tool supports rapid configuration and execution of binary models, where locations with a cell state of 0 transition to a new state of 1 if a simple set of conditions are met.

Table of Contents

1. Tool Inputs
   1. Required Inputs
   2. Optional Inputs
2. Usage Instructions
   1. Step 1. Provide input and output parameters
   2. Step 2. Specify the neighborhood function
   3. Step 3. Specify the transition rule conditions
   4. Step 4. (Optional) Configure suitability map requirements
   5. Step 5. (Optional) Configure areal restrictions.
   6. Step 6. Verify model parameters.
   7. Step 7. Run the Basic Cellular Automata.
   8. Step 8. View results and model parameter report.

Tool Inputs

All raster data layers provided as input to the Basic Cellular Automata tool must adhere to the Data Preparation guidelines.

Required Inputs

• A binary raster data layer containing only 1s and 0s

Optional Inputs

• A custom neighborhood definition (.nb file) outputted from the Neighborhood Definition tool.
• A suitability, susceptibility, or probability map containing continous decimal values from 0 to 1, where 1 indicates locations that are the most “suitable” for a change to occur.
• A binary constraint map indicating 1s where changes are permitted and 0s where changes cannot occur.

Usage Instructions

Step 1. Provide input and output parameters

Provide a file path to a binary raster data layer, the output geodatabase name that will be created for the simulation outputs, the prefix for naming the Esri GRID files outputted to the new geodatabase, and the number of iterations to execute the cellular automata model for.

Step 2. Specify the neighborhood function

Use the dropdown and slider to configure any of the preset neighborhood types. Alternatively, you can provide the file path to a custom Neighborhood Definition (*.nb) file created with the Neighborhood Definition tool.

Step 3. Specify the transition rule conditions

Specify the conditions of the neighborhood required for the rule to take effect. This can be expressed as a percentage of neighborhood composition or as the number of influencing cell locations that must have a cell state of 1 for the change to occur. Note that the number of cells or percentage of neighborhood composition will be calculated with respect to the neighborhood settings provided in Step 2. Setting a Transition Rule Probability allows users to introduce randomness in rule behavior. Set the probability value to 100 to create a deterministic model.

Step 4. (Optional) Configure suitability map requirements

Optionally, you can provide a suitability, susceptibility, or probability map to refine change allocations. To use this option, provide a file path to the normalized raster data layer (see Data Preparation instructions for more information). Next, you can provide a minimum required suitability value between 0 and 1, a number of cells permitted to transition, or use both settings simultaneously. If no suitability map should be used, set this option to “None.”

Step 5. (Optional) Configure areal restrictions.

Another optional input is a constraint map. To use this option, provide a file path to the binary raster data layer (see Data Preparation instructions for more information). If no constraint map should be used, set this option to “None.”

Step 6. Verify model parameters.

Once all the required parameters are set (and any optional inputs), click the Verify Model Parameters button. The routine will check that all inputted raster data layers adhere to the requirements indicated in the Data Preparation guidelines, that all file paths are valid, and that input fields contain no errors.

If the model verification process is successful, you will see the following message. Click “Okay” to close the window.

If the model verification fails, the verification message dialog will display a list of the issues that need to be resolved before the model can be run.

Step 7. Run the Basic Cellular Automata.

After the model parameters are verified, the Run Basic CA Model button will be enabled. Clicking this button will start the modeling procedure. Note that outputs added to the map will be shown fully after the model execution procedure is completed.

Step 8. View results and model parameter report.

The simulation results will automatically be added to the map contents.

To find the Model Parameter Report, find the new “CAOutputs” folder created in your project directory and double click the HTML file to open it in your default web browser.