The major change in the site parameters from verion 4 to 5 is addition of layered soil. After importing your Century 4 site file, edit the soil layer thickness, texture and bulk density values, as well as NLAYER and NLAYPG, to reflect the real soil on the site. More information on the layered soil structure is in the section Soil Physical Structure Submodel. A new algorithm for estimating depth distribution of soil organic C may have difficulties with an improperly configured physical soil. See the section Depth Distribution of Soil Carbon for more details on this algorithm.
The site mneumonic retains that name for compatibility with Century 4, but now can be 20 characters in length. You may want to modify the original name to be more descriptive. For example, rather than a cryptic Century 4 name of "SVNA", you can name your site "Savanna".
New fields available in the Century 5 site files, available in the Site Parameters Editor, are:
New parameter catagories in the Century 5 sites apply to erosion and deposition:
In Century 4, management blocks are linear and repetitive sequences of events. In Century 5, blocks are organized into block definitions, and block instances. Definitions specify a sequence of events, and are identified by name and a unique event sequence. Instances of the blocks specify the use of the block in the simulation time.
Upon importing a Century 4 management schedule, identical blocks are combined, and blocks are numbered (See the dialog page "Define Blocks" in the Management Editor.) If there is a comment string at the beginning of the Century 4 block, the string is appended to the name. After importing, you may want to give your blocks names reflecting their contents (e.g., "corn-soybean"). Don't forget to save your imported schedule as a Century 5 management scheme!
You can examine your imported management schedule with a verification process, to check for actual or potential problems. A "Verify" button at the bottom of the Management Editor performs the verification check, and results are written to the message window.
New fields available in the Century 5 management scheme, available in the "Simulation Information" dialog page, are:
First, see the list of error messages and their explanations in the section Century Error Messages. If you have just imported a Century 4 site or management file, see the sections above regarding considerations upon importing.
If you think you have found a real bug in the Century or CMI operation, please send detailed information to the Century help desk. See Contacting NREL for more information.
Century Error Messages
Editing Site Management