Traffic NO2 Overlay

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What is the Traffic NO2 overlay?

Active Traffic NO2 air polution 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

File:Traffic NO2-Overlay Legend.jpg
Traffic NO2 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]


Cb,jm= 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]
  • fNO2 = weighted fraction direct emitted NO2 [-]
  • B = parameter (default 0.6)
  • K = parameter for conversion NO to NO2 (default = 100 μg/m3)

References

The overlay calculations are based on Standard Calculation Method 1 (SRM1) as defined by the dutch government: wetten.overheid.nl