AERMOD View – EVENT Processing
November 2014
When modeling with source groups in the AERMOD air dispersion model, it is not always obvious how much each sources contributes to a calculated concentration. To facilitate source contribution analysis, AERMOD includes routines called EVENT processing which analyze user-specified events (e.g., design concentrations, threshold violations) and print each source’s contribution to the event.
To start EVENT processing, you must first have AERMOD produce an EVENT processing input file. This is done via the Control Pathway. In AERMOD View, you’ll find this option under the Event/Error Files section.
To start EVENT processing, you must first have AERMOD produce an EVENT processing input file. This is done via the Control Pathway. In AERMOD View, you’ll find this option under the Event/Error Files section.
There is an option to print on the source contribution output (Source Contribution) or printing the full detailed output from the EVENT processing run.
With this option enabled, AERMOD creates a list of events. By default, design concentrations (the output options defined in the Receptor Table of the Output Pathway) and any threshold violations identified in the Threshold Violation Files (OU MAXIFILE keyword) are written to the EVENT processing input file.
The image below is an example EVENT processing input file containing high-first-high and high-second-high concentrations for the 3-hour and 24-hour averaging periods in addition to a few threshold violation events.
With this option enabled, AERMOD creates a list of events. By default, design concentrations (the output options defined in the Receptor Table of the Output Pathway) and any threshold violations identified in the Threshold Violation Files (OU MAXIFILE keyword) are written to the EVENT processing input file.
The image below is an example EVENT processing input file containing high-first-high and high-second-high concentrations for the 3-hour and 24-hour averaging periods in addition to a few threshold violation events.
The next step is to run AERMOD again using the EVENT processing input file. This will initialize the EVENT model run to calculate source contributions. In AERMOD View, this is done via the Run menu.
EVENT could be run without software by calling the AERMOD executable with the EVENT processing input file instead of the standard AERMOD input file.
The detailed EVENT output file will contain information such as met data conditions during the processed hour(s) and each source’s hourly concentration during the time step.
The detailed EVENT output file will contain information such as met data conditions during the processed hour(s) and each source’s hourly concentration during the time step.
