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Air Quality Modeling

URBEMIS 2007 (version 9.2.4)

The URBan EMISsions (URBEMIS) 2007 model (version 9.2.4), which estimates air pollution emissions from a wide variety of land use projects, is now available. The latest version of the model has been rewritten in and offers many new features. The model's format has been revised to make it easier to use. When starting URBEMIS, seven steps are shown to guide the user from start to finish.  The software for the model, as well as the user manual, can found on the URBEMIS 2007 for Window (version 9.2.4) website.

The URBEMIS 2007 model uses the California Air Resources Board's EMFAC2007 model for on-road vehicle emissions and the OFFROAD2007 model for off-road vehicle emissions. Two new pollutants have been added: PM2.5 and carbon dioxide. Construction phases can now be added and removed by the user, and phases can overlap. The Construction report for daily emissions is displayed as a series of "time slices" that represent emissions associated with overlapping and non overlapping phases. The time slice that represents the maximum emissions for each pollutant is underlined for easy recognition. Area Source and Operational data entry forms have been redesigned for easier data input. Mitigation measure control efficiencies have also been updated.

URBEMIS 2007 version 9.2.4 was released February 2008 to include the first plug-in module that allows the user to create and save a file that lists individual pieces of construction equipment that can be assigned to a project's construction phase.  Version 9.2.2 was released September 2007 (an update to the original version 9.2.0 released in June, 2007) and a training class was conducted on September 19, 2007, to discuss the new features of the updated model, as well as guide the user through the mechanics of the model.  The training session was webcast and the archive is available for viewing.  In addition, the training overhead presentation (2.5 kb, ppt file) is also available.

Major enhancements for the version 9.2 include:

  • Improved appearance and organization of URBEMIS to make it easier and more intuitive for the novice user while providing more options for the power user.

  • Fixed bugs discovered in version 8.7.

  • Uses EMFAC2007 emission factors (for on-road mobile sources).

  • Allows the user to select air basin and county specific EMFAC and default files.

  • Uses OFFROAD2007 emission factors (for off-road mobile sources).

  • Allows all construction phases to overlap.

  • Allows the user to specify additional construction phases.

  • Enhanced procedure for estimating and mitigating architectural coating emissions.

  • Refined estimates of default construction equipment based on data collected by the air districts.

  • Improved reporting capabilities, including selectable emission estimates, plus reporting for two additional pollutants: PM2.5 and CO2


The program changes reflected in the previous URBEMIS model versions 8.7.0 and 7.5.0 can be found on the Frequently Asked Questions page.


For technical support, please e-mail comments or questions to   Please provide a contact name, phone number, address and e-mail address.