Encyclopedia of Environmental Science and Engineering, Volume I and II

1174 URBAN AIR POLLUTION MODELING

Leeward

side

Windward

side

Direct plume

Recirculating air

Background pollution

Roof level wind

FIGURE 3 Schematic illustration of flow and dispersion of pollutants in street

canyons (From Berkowicz, 2000a, with permission of Springer Science and

Business media).

Advection

Transport

Reaction

Net Loss

85

1000 23

22

26

61

26

29

52

21

26

15

14

910

2

4

3

8

2

3

<1

<1

<1

<1

<1 <1

<1

5

WATER SOIL

SEDIMENT

FILM AIR VEG’N

FIGURE 4 Estimated rates of chemical movement and transformation for 2,3,7,8-CL 4 DD based on an emission of 1 mil/

hour into air. Numbers shown are transport rate in mmol/hour (From Diamond et al., 2001, with permission from Elsevier).

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