Models Knowledge Base

About the Models Knowledge Base

This Models Knowledge Base (KBase) is an inventory of EPA's environmental models. Developed by EPA's Council for Regulatory Environmental Modeling (CREM) at the request of the EPA Administrator (February 2003), it is intended to provide information about how a model is used and about a model's underlying science.

EPA's program and regional offices worked with the CREM to develop this KBase. At the CREM's request, the EPA offices selected models they deemed to be most frequently used. They then submitted information on these models, according to a data template, provided by the CREM. The data template reflects the information that the CREM guidance on models generally recommends for all models. Therefore, while the CREM developed the infrastructure and data requirements for this KBase, the information being provided was submitted by the various EPA offices.

The fact that a model is in this Models KBase does not necessarily mean that EPA endorses the model; conversely, the fact that a model is not included does not mean that it may not be appropriate for a particular use. As noted in the CREM guidance on models, the appropriate use of a model depends on the particular purpose to which it is applied. Not knowing every purpose for which a model may be used, EPA has resisted the idea of endorsing or even ranking or "scoring" models in this KBase. Rather, the Agency hopes that model users-by using the information in this KBase and by relying on recommendations provided by the CREM guidance on models will make an informed choice when using a model.

EPA recommends that models should only be used for the particular application for which they were designed and only after they have been appropriately evaluated. Decisions about the suitability of a specific model for a particular application should be made in consultation with experienced model users (viz. EPA staff, EPA contractors, or staff of other agencies), as necessary.

Models Knowledge Base User Guide

The Models Knowledge Base serves as a central repository, to facilitate model selection and provide pointers to the home pages for individual models. The Models Knowledge Base facilitates the identification and selection of models with three tools (List All, Keyword Search and Browse). The "List All" tool allows the visitor to view a list all available models. The "Keyword search" performs a search on the models' abstracts and information. The "Browse" tool allows the user to search for applicable models by selecting the relevant environmental indicators. The classification scheme for this tool is adapted from EPA's hierarchy of environmental indicators. Using this tool, selection of relevant criteria for a particular modeling activity yields a list of models from the Models Knowledge Base that best match these criteria.

Each model's record includes three pages of information. The General Information page includes an overview of the model, contact information, and a link to the model's homepage. The second page, Model Use, provides information that is essential for potential users, including technical requirements (hardware, operating systems, and software), directions for obtaining (downloading) the model, and basic information on using the model (model inputs, model outputs, and the User's Guide). The final page, Model Science, includes sections on the conceptual basis of the model, scientific detail, model framework, and model evaluation. These pages are intended to contain the types of information that are recommended by the CREM guidance on models and that would be beneficial to prospective model users.

• Environmental Models currently available
• Guidance for Environmental Models
• Data Structure
• Latest Updates to the Knowledge Base

• Listing of all available models
  
• Keyword search
  
• Browse for models by selecting environmental indicators

The CREM's Draft Guidance for Environmental Models provides recommendations for model development, evaluation, and application. The Models Knowledge Base is intended to be a living demonstration of the recommendations from the Guidance for Environmental Models. In this way, these two products work in tandem to describe and document good modeling practices.

The CREM Models Knowledge Base is continually updated with records for new models and with revised records for existing models. The 10 latest additions or revisions are: