Getting Started with CMI

Necessary Steps

The Century Model Interface provides an easy, flexible and complete graphical user interface to Century. This interface allows you to configure and run a Century simulation and to view results.

Preparing for a simulation involves building a set of site parameters, and a management scheme for the simulation. Generally you will use a predefined set of parameters and management as a starting point for your configuration.

NOTE: Not all of the options described below are implemented in the latest version of CMI.

Two general approaches to configuring a simulation are available. First, there is a five-step method with minimal user interaction with model configuration, in which you proceed through the following sequence:

1. Specify a folder in which to keep your simulation files. Under the menu bar item Tools , select Preferences .
2. Select a biome or site from a map image, from latitude and longitude, or by name. You have the option to edit the site characteristics (that is, the parameters relating to that site). The site selected is then automatically modeled for 2000 to 3000 years to reach equilibrium. You next use the output from this equilibrium determination as the basis for the remaining steps.
3. Choose a management method from a list of methods associated with the biome or site. You have the option to edit the management methods and scheduling.
4. Specify the years over which the model is to run. Years can be entered as (i) the start and finish years, or (ii) as the beginning year and the number of years.
5. Run the model and view the results.

A second approach you can immediately begin detailed modifications to parameters and management without having to proceed through the sequence of steps in the first method. Also, you can perform these modifications at any point during the automated approach. Tasks include the following:

1. Specify a folder in which to keep your simulation files. Under the bar menu item Tools , select Preferences .
2. Create a new site, or choose an existing site, and edit site characteristics by modifying the model parameters describing that site. Site characteristics are parameters describing physical characteristics, soil C, C isotopes, and weather.
3. Create a new management plan, or choose an existing management plan, and edit the management by modifying the block definitions and scheduling.
4. View results from previous model runs.

Management Schemes

In the both approaches, you can develop site management schemes using methods with three levels of complexity:

1. You can select an entire pre-defined management scheme and apply it with or without further modification.
2. Build a new management scheme by combining small, predefined blocks of management events and specifying the years of application of each block.
3. Create a new management scheme entirely from scratch.

Suggestions

1. Define a new simulation parameter set by selecting from a list of sites in the libraries. Select the site based upon the latitude and longitude, or biome to match the site you want to simulate. Then modify only those parameters whose values you need to customize. This will be far less work than creating your own set of site parameters from scratch.
2. Specify a management scheme by selecting a scheme from the management libraries that matches most closely the management motif you need. Then, modify the simulation years, the use of the management blocks, and the simulation output according to your needs.

Where To Go Next