Traffic NO2 Overlay: Difference between revisions
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The calculations follow the standard rekenmethode 1 (SRM 1), as described on [http://wetten.overheid.nl/BWBR0022817/2013-03-22]: | The calculations follow the standard rekenmethode 1 (SRM 1), as described on [http://wetten.overheid.nl/BWBR0022817/2013-03-22]: | ||
Cjm = Ca,jm + Cb,jm | '''Cjm = Ca,jm + Cb,jm''' | ||
where: | where: | ||
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To compute the annual average traffic contribution to NO2, Cb,jm[NO2] [μg/m3], the following formula from SRM1 is applied: | To compute the annual average traffic contribution to NO2, Cb,jm[NO2] [μg/m3], the following formula from SRM1 is applied: | ||
Cb,jm[NO2]= fNO2 * Cb,jm[NOx] + (B*Ca,jm[O3]*Cb,jm[NOx]*(1-fNO2))/(Cb,jm[NOx]*(1-Fno2)+K) | '''Cb,jm[NO2]= fNO2 * Cb,jm[NOx] + (B*Ca,jm[O3]*Cb,jm[NOx]*(1-fNO2))/(Cb,jm[NOx]*(1-Fno2)+K)''' | ||
where: | where: | ||
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To compute the annual average traffic contribution to NOX, Cb,jm[NOX] [μg/m3], the following formula from SRM1 is applied: | To compute the annual average traffic contribution to NOX, Cb,jm[NOX] [μg/m3], the following formula from SRM1 is applied: | ||
Cb,jm[NOx] = Fk * E * θ * Fb * Fmeteo | '''Cb,jm[NOx] = Fk * E * θ * Fb * Fmeteo''' | ||
* Fk = calibration factor [-] (default = 0.62] | * Fk = calibration factor [-] (default = 0.62] | ||
Revision as of 13:49, 13 June 2018
What is the Traffic NO2 overlay?
The Traffic NO2 overlay is an Overlay which displays the impact of traffic air polution (in μg/m³ nitrogen dioxide) in different colors for the project area. These colors indicate traffic air polution of a location based on traffic flow and distance.
Traffic NO2 air polution overlay colors
Calculations
The calculations follow the standard rekenmethode 1 (SRM 1), as described on [1]:
Cjm = Ca,jm + Cb,jm
where:
- Cjm = annual average concentration [μg/m3]
- Ca,jm = annual average background-concentration (default = 0 [μg/m3], can be adjusted via the overlay attributes)
- Cb,jm = annual average traffic contribution to NO2 concentration [μg/m3]
To compute the annual average traffic contribution to NO2, Cb,jm[NO2] [μg/m3], the following formula from SRM1 is applied:
Cb,jm[NO2]= fNO2 * Cb,jm[NOx] + (B*Ca,jm[O3]*Cb,jm[NOx]*(1-fNO2))/(Cb,jm[NOx]*(1-Fno2)+K)
where:
- Cb,jm[NOX] = annual average traffic contribution to NOx concentration [μg/m3]
- Cb,jm[O3] = annual average concentration ozon [μg/m3] (default =
- fNO2 = weighted fraction direct emitted NO2 [-]
- B = parameter (default 0.6)
- K = parameter for conversion NO to NO2 (default = 100 μg/m3)
To compute the annual average traffic contribution to NOX, Cb,jm[NOX] [μg/m3], the following formula from SRM1 is applied:
Cb,jm[NOx] = Fk * E * θ * Fb * Fmeteo
- Fk = calibration factor [-] (default = 0.62]
- E = emission value [μg/m/s]
- θ = delution factor [-]
- Fb = tree factor (default = XX)
- Fmeteo = 5/windspeed. Default value for windspeed is 5 m/s
References
The overlay calculations are based on Standard Calculation Method 1 (SRM1) as defined by the dutch government: wetten.overheid.nl