METI-LIS Technical Manual

forecasting suspended particulate pollutants. This model introduces a correction coefficient
α and expresses the deposition effect through an additional term in the dispersion equation.
C(x, y, z)
( He − V x / u − z)
( He − V x / u z)
2 ⎡
2
2
Q y
⎤
s
s +
= exp( − ) ⎢exp(
−
) + α( x)
exp( −
) ⎥
2πσ
u
2
2
2
yσ
z 2σ
y ⎢⎣
2σ
z
2σ
z ⎥⎦
(3.4)
α
( x)
2V
d
= 1−
(3.5)
V + V +
s
d
( uHe −V
x) / σ × ( dσ
/ dx)
s
z
z
Vd = Vs
+ 0. 006u
(3.6)
FLUX = V C x,
y,
z )
(3.7)
d
(
ref
Table 3.5: Particulate deposition equation symbols
Symbol
Definition
Q
Volume of emitted particulate
C
Concentration
x, y Coordinates (x represents the downwind axis)
z
ref Reference height
FLUX
u
V
d
Deposition volume of the pollutant
Mean wind speed
Dry deposition velocity
3.2 Line Source Model
3.2.1 Dispersion Equation
Sources with line-shaped characteristics are found by numerically integrating the
point-source plume equation, Equation 3.8.
C(x, y, z)
2
( z − He) ( z He)
2 ⎡
2
Q y
+ ⎤
= exp( − ) ⎢exp(
− ) + exp( − ) ⎥
2πσ
u
2
2
2
yσ
z 2σ
y ⎢⎣
2σ
z
2σ
z ⎥⎦
(3.8)
-32-