Environmental Engineering Reference
In-Depth Information
Δ
NO:
-30.0% -20.0% -10.0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0%
50
+10%
40
30
20
10
0
0
20
40
60
80
100
120
140
160
180
200
x
Fig. 3.
Mean relative difference in the vertical plane in NO-concentrations with and without a
vegetation barrier
4. Conclusions
Both the measurements and the ENVI-met model results show that a vegetation
barrier along a motorway can have a local positive effect on the air quality at the
downwind side of the motorway. For nitrogen oxides both the model and the
measurements show similar relative effects caused by the vegetation. For PM, model
results do not agree with the measurement campaign. However due to exceptional
meteorological conditions, only limited measurement data for PM was available. It
would be to premature to draw conclusions based on this limited data set.
Both the measurement campaign and the modelling are a first attempt to better
understand the effect of a vegetation barrier along a motorway. A second and third
measurement campaign are conducted and currently being analysed. Those results
will help to give more insight in the processes and to improve the modelling.
References
Bruse, M. and H. Fleer, (1998) Simulating surface-plant-air interactions inside urban
environments with a three dimensional numerical model, Environmental Modelling and
Software, 13, 373-384.
Weijers, E. P., G. P. A. Kos, W. C. M. van den Bulk and A. T. Vermeulen, (2007) Onderzoek
naar de luchtkwaliteit rondom een vegetatiestrook langs de snelweg, Technical report
ECN-E--07-011, Energy Research Center of the Netherlands.
