Traffic NO2 formula (Traffic NO2 Overlay): Difference between revisions
| Line 52: | Line 52: | ||
where: | where: | ||
: <math> ENO_2</math> = emission number NOs [μg/m/s] | : <math> ENO_2</math> = emission number NOs [μg/m/s] | ||
====Tree Factor==== | |||
The tree factor is calculated as followed: | |||
<math></math> | |||
====Emission numbers==== | ====Emission numbers==== | ||
Revision as of 17:08, 1 March 2022
The calculations follow the standard rekenmethode 1 (SRM 1).
![{\displaystyle Cjm[NO_{2}]=Ca,jm[NO_{2}]+Cb,jm[NO_{2}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/84cb1e5a8a0dd74d8b9cec6cb2c58c97cecc6227)
where:
- = annual average concentration [μg/m3],
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Ca,jm[NO_2]} = annual average background-concentration (default = 0 [μg/m3], can be adjusted via the overlay attributes),
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[NO_2]} = annual average traffic contribution to NO2 concentration [μg/m3].
![{\displaystyle Cjm[NO_{2}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8add707b3d3ac95cf59973e4a7d511df9d73a5bc)
Contribution NO2
To compute the annual average traffic contribution to NO2, Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[NO_2]} [μg/m3], the following formula from SRM1 is applied:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[NO_2]= fNO_2 \cdot Cb,jm[NO_x] + \frac{B \cdot Ca,jm[O_3] \cdot Cb,jm[NO_x] \cdot (1-fNO_2)}{Cb,jm[NO_x] \cdot (1-Fno2)+K}}
where:
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[NO_x]} = annual average traffic contribution to NOx concentration [μg/m3],
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[O_3]} = annual average concentration ozon [μg/m3] (default = 42),
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle fNO_2} = weighted fraction direct emitted NO2 [-],
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle B} = parameter (default 0.6),
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle K} = parameter for conversion NO to NO2 (default = 100 μg/m3).
Contribution NOX
To compute the annual average traffic contribution to NOX, Cb,jm[NOX] [μg/m3], the following formula from SRM1 is applied:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Cb,jm[NO_x] = Fk \cdot ENO_x \cdot \theta \cdot Fb \cdot Fmeteo}
where:
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Fk} = calibration factor [-] (default = 0.62]
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle ENO_x} = emission number NOx [μg/m/s]
- = dilution factor [-]
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Fb} = tree factor (default = 1)
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Fmeteo} = 5/windspeed. Default value for windspeed is 5 m/s
The dilution factor, Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \theta} , is computed till a distance of 30m with:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \theta = a \cdot S^2 + b \cdot S + c}
And from 30-60m (for road-type 1 and 4 only):
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \theta = \alpha \cdot S^{-0.747}}
where:
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle S} = the calculation distance
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a} , Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle b} , Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle c} and Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \alpha} = parameters depend on road-type:
The weighted fraction of direct emitted NO2 [-] is computed as:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle fNO_2 = \frac{ENO_2}{ENO_x}}
where:
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle ENO_2} = emission number NOs [μg/m/s]
Tree Factor
The tree factor is calculated as followed: Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle }
Emission numbers
The emission numbers (E) for both NOx and NO2 are computed as:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E = N \cdot [(1-FS)\cdot((1-(fm+fz+fb))\cdot El + fm \cdot Em + fz \cdot Ez + fb \cdot Eb) + FS \cdot ((1-(fm + fz + fb)) \cdot El,d + Fm \cdot Em,d + fz \cdot Ez,d+fb*Eb,d)] \cdot \frac{1000}{(24 \cdot 3600)}}
where:
- N = traffic intensity [units per day]
- fm = fraction vans [-]
- fz = fraction trucks [-]
- fb = fraction buses [-]
- El = emission value cars [g/km]
- Em = emission value vans [g/km]
- Ez = emission value trucks [g/km]
- Eb = emission value buses [g/km]
- FS = fraction congested traffic [-]
- E*,d = emission factor per class (cars, vans, trucks or buses) if congested
Notes
- If the traffic amount is defined as a single value, that value is used for all defined hours. However, if the amount if an array of values, each of the 24 indexes of that array are assumed to correspond to the hour denoted by those indexes, and as such that specific value from the array is used.
- The SRM1[1] calculation method is only applicable for urban environments.
See also
References
- ↑ SRM1 ∙ Regeling beoordeling luchtkwaliteit 2007, Bijlage I ∙ Found at: http://wetten.overheid.nl/BWBR0022817/2013-01-01#Bijlage1 ∙ (last visited: 16-02-2022)