Input data IV · software · outdoor air pollution
DISPER: 16 air quality management 17 air quality guidelines 18 outdoor air pollution 19 air pollution cause 20 environmental science 21 environmental monitoring 22 environmental impact assessment 23 indoor air quality 24 environmental assesment 25 air monitoring 26 modelling emissions 27 software · pollution 28 environmental engineering 29 atmospheric pollution 30 air pollution 31 environmental maps
Ambient conditions are defined by the land and atmospheric conditions in the vicinity of the pollutant emission. This Menu lists: Meteorology and Topographic lines.
Meteorology: DISPER analyses, as all mixing zone evaluations, are usually carried out under the assumption of steady-state ambient conditions. If you click this command, the next dialog box is shown:
The necessary data in the Meteorology command is:
Pasquill stability: Classification scheme that describes the degree of atmospheric turbulence. Categories range from extremely unstable (A=1) to extremely stable (F=6). Unstable conditions promote the rapid dispersion of atmospheric contaminants and result in lower air concentrations compared with stable conditions.
Wind speed at reference anemometer height (m/s): The measurement of wind speeds is usually done using a cup anemometer. The cup anemometer has a vertical axis. The number of revolutions per minute is registered electronically.
Wind angle (0 to 360 degrees): It is the horizontal angle of wind measured clockwise from the North (at the window top).
Ambient temperature (K): The temperature of the medium surrounding an object. This is the air temperature at stack location.
Mixing height (m): Mixing Height is used by meteorologists to quantify the vertical height of mixing in the atmosphere. It is the height at which vertical mixing takes place. There is a smaller volume which the pollutant can be dispersed. There is a seasonal variation of mixing height. For Summer daylight hours maximum mixing height can be a few thousand feet where as for Winter it can be a few hundred feet. It is lowest at night and increases during the day.
Anemometer height (m): This is the ambient temperature at stack location.
RURAL/URBAN option: This is the RURAL/URBAN terrain options.
Obtain K value: With this button, you can estimate the Pasquill stability category if it is unknown. If you know the K value, you don't need to use this command. You can write it directly in the Meteorology window. If you click this button, the next dialog box is shown:
outdoor air pollution
Outdoor air pollution: The environmental pollution can be controled by means of this program. The software works with several different air dispersion models from european and american environmental agencies.