AirWare Reference Manual: poulation exposure

AirWare On-line Reference Manual

Release Level 5.4
Release Date 2008 10

Revision Level 1.0

Last modified on: Monday, 20-Jul-09 14:03 CEST

Population Exposure

Model results scenarios can also be interpreted in terms of population exposure, if an appropriate data set of population data (polygon or raster based) is available for the model domain.

The population exposure is available from evyer model results scenario from the button: popexp, upper edge of the map window.

The button leads to a separate page that inherits the model scenario including domain and color configuration. On top of the concentration (or air quality index) display, the populated area where a substance and aggregation time specific standard is exceeded, is shown in RED. In addition, a numerical summary (area and number of people exposed) is also shown under the concentration distribution histogram.

Data and files

The population distribution (density) is defined in a regular raster (default: 100 m resolution, 1 ha) generated from an appropriate shapefile, which is also available in the embedded GIS as an overlay.
The default path for the file is: /gis/APPLICATION/data/population.density. The default thresholds for the computation of exposure are defined in a configuration file, namely: /var/www/cgi-bin/exposurelimits which is a simple ascii file with the format: ANY ANY 100 POLLUTANT_NAME PERIOD THRESHOLD which defines: the pollutant or index the aggregation period the default threshold where the first record with ANY, ANY defines a global default if no specific value for a given combination of substance and aggregation period can be found. The values are defined in the unit that is associated with the respective pollutant or index in the Knowledge Base. Implementation note Population exposure is calculated for populated areas irrespective of population density. A second parameter (population density, default: 0.0) could be used to limit the calculation to areas above a certain population density threshold.