Introduction to AIM/Enduse[Air]AIM APEIS TWS in NIES
Date Oct. 18
Takeshi Fujiwara
Kyoto University

Purpose• To calculate diffusion of air pollutant
emitted from three kinds of sources:– LPS: emission from large point source which
has a tall stack, such as power plant, boiler orreactor in factory, waste incinerator, and soon.
– AS: area source having a lower emission
point, such as factory having a low stack,transporters, houses, fields, and so on.
– LS: line source such as traffic road.

Characteristics• Air quality modeling in the framework of AIMfamily• One of supplementary models of AIM/Enduse• SO2, NOx, are target pollutants.. (SPM is thethird target of pollutant)• Pollutant concentration in every hour during
specified period is calculated.
• Evaluation of health risk related to energy use
through calculation of air pollutant concentration.

(A)Emissionprojection

AIM/Air General Data Flow Diagram

AIM/Local

(B)

A-GIS
AGIS.rst(C)

Emissionpatterns

Target area

editEpat

editGmap

epat.airgmap.airconvAGIS
Meteorological dataagis.air
ECMWFLPSAS(D)Local measurement
local.air

readGRBX
Integrationof LPSemission data

Stability
calculation
for LPS(E)

editLPS
emitLPS.air

editAS
emitAS.air(F)

stabLPS
stabLPS.air

stabAS
stabAS.air

Integrationof AS
emission datau.air
u.air
u.air

softwarefile

Stability
calculation
for AS(H) Concentration
visualizationdiff(G)

Diffusion
calculationdiff.airConcentration

viewCont

Viewer(Connect to health impact assessment module)

Develop a database of emission patterns
representing hourly, daily, andEdit large(A) point source (LPS) data. Select anemissionof the LPS from the definedmonthly changes in emission, sector
Emission pattern
AIM/Localpatterns. Moreover, edit area source (AS) by sector.
projection(B) cell
data. Select anA-GIS
emission pattern of each(C)from the defined patterns.Emission

AIM/Air General Data Flow Diagram
patterns

Target area

editEpat

editGmap

epat.airgmap.air

AGIS.rst
convAGIS

Meteorological data

agis.air
ECMWF
LPS

AS

The interface between AIM/Enduse and AIM/Air.
Convert the pollutant emission from each district
Integration
editLPS
editAS
into the grid matrix
data of(E)emission byusingof LPS
the converter software, A-GIS (on IDRISI),
emission data
emitLPS.air
emitAS.air
sector by sector.

Stability
calculationfor LPS(F)

stabLPS

stabAS(D)

Local measurement

local.air
Calculate the index of readGRBX
atmospheric stability
foreach LPS and each cell of AS. Diffusion
parameter corresponding to the index is calculated

Integrationof AS
emission data

u.air
u.air
u.air

Calculate the concentration distribution of airsoftware

Stabilityouton
thediffusion
meteorology
data (plumeofthefile
pollutant Cutbased
equationscalculation
target area from the worldwide
Make grid map corresponding
for target
ASand puff models).
stabLPS.airstabAS.air to thearea. A cell in the gird means a unit of areasource and a receptor position where thepollutant concentration is calculated.
diff(G)

Diffusion
calculation

Concentration

meteorology data ECMWF, and(H) Concentrationinterpolateand form the data.
visualization
Another meteorology datameasuredby local observation
sites
ViewerviewCont
diff.airare also available.
(Connect to health impact assessment module)

Emission pattern generator (1)Emission Pattern generator (2)GUI to input emission pattern.

Hourly pattern

Daily pattern

Monthly pattern

Note: Term of special holidays is also taken into account.

Grid map editor

AS Emission Editor (1)AS Emission Editor (2)LPS Emission editor

Specification of AIM/Air software•

Grid size: fineness of the gird is restricted by the limitation of CPU power
and memory size.
– Ex 1) the size of the target area is 100km x 100km, and cell size of the grid is 1
km x 1 km– Ex.2)the size of target area is 10km x 100km, and cell size of the grid is 100m x
100m. The balance of the target size and cell size are flexibly adjustable.

•••••
•

Emission pattern of LPS should be designed according to the actual
operation schedule in the factory. That of AS cell should be designed byconsidering land use, several kinds of industrial area, residential area, traffic
path, agricultural field, and so on.
Hourly, weekly and monthly change in emission intensity can be defined.
The meteorology data locally corrected at observation sites are available forthe diffusion calculation.
Pollutant concentration in every hour during specified period is calculated.
Effective computational algorithm to calculate plume-type diffusion from AS
cells is implemented.
GUI is available on PC computer, and software can run on both PC andLinux.

Plume modelThis diffusion equation is used when the wind velocity is more than 1(m/s).

⎧⎪⎛ ( z − H )2 ⎞ ⎛ ( z + H )2 ⎞ ⎫⎪⎛ y2 ⎞ee⎜⎟⎜⎟⎬−+−C ( x, y , z ) =exp ⎜ −exp⎟⎨2 ⎟22⎜⎜⎟ ⎜⎟⎪2πσ yσ z u2σ z2σ z⎝ 2σ y ⎠⎠ ⎝⎠⎭⎩⎪⎝QP

x: downstream coordinate, y: horizontally transverse coordinate, z:vertical coordinate (representative height=1.5m), Qp: emission frompoint source (kg/year), u: wind velocity (m/s), σy, σz：diffusion
coefficients of coordinate y and z (m)Effective stack height

Diffusion parameters
αyσ y = γ y ⋅ x , σ z = γ z ⋅ xαz

H e = H + ΔH
1

ΔH = 0.175QH uh
2−34

QH = ρ C p qg (Tg − T0 )

Image of plume diffusionwinddirection(downstream)
EffectiveheightstackheightdiffusionstackPuff modelThis diffusion model is used in the case of no wind or very weak wind.
⎡ 1 ⎧⎪⎤⎛
π 2 ⋅ ux
⎛ u 2 x2 ⎞ux ⎞⎟⎫⎪⎜⎜⎟exp⎜ 2 2 ⎟erfc⎜ −⎢ 2 ⎨1 +⎥
⎬
⎟
2αη
2
η
α
η
2αη
⎥
−− ⎠⎝
⎛ u ⎞ ⎢ − ⎪⎩⎝− ⎠⎪QP⎭⎜⎟−exp
C ( x, y , z ) =⎢
⎥
2 2⎧⎫
⎛
⎞
(2π )3 2 γ ⎜⎝ 2α 2 ⎟⎠⎢π 2 ⋅ ux
⎛ u x ⎞1 ⎪ux ⎟⎪⎥⎜⎟⎜−++1exp
erfc⎨⎢
2⎜ 2α 2η 2 ⎟⎟⎬⎪⎥⎜αηηαη2⎪++ ⎩− ⎠⎝+ ⎠ ⎭⎥⎢⎣⎝⎦α2η = x + y + 2 ( z − H e )2γ
2−22α2
η = x + y + 2 ( z + H e )2γ2+erfc(W ) =2

1

2

∞−te
∫ dt

π W

2

Image of puff diffusion
diffusion

Effective
heightstack
heightstackMethod for AS
AS and Receptor cells
100m
Fine cells
10mRequired data in AIM/Enduse[Air]Emissionquantity

Annual quantity (kg/year), sector by sector, output from Enduse
model.

Emissionpatterndaily, weekly, and monthly change in emission, sector by sector

LPS

location (latitude and longitude), stack height, gas(flow,temperature, specific heat)ASland-use map, emission height, gas(flow, temperature, specificheat)LSroad map, traffic volume by transporter-type, emission factor(kg/m) by transporter-type

Meteorology
datawind direction and velocity, air temperature, solar radiation,
cloud coverLand use in Beijing city

Public building
公共建築
area

Commercial
商業中心区
area

School &学校&病院

Hospital area

Residential
居住areaIndustrial
area &工業&倉庫
WarehouseEmission from residential area
(grid map data)
1.00E+05

0.0

Contribution to Air Pollution inBeijing
Daily averaged SO2 concentration

1.2

1.0
PublicCommerce
Transport
OthersNonferrous
Iron & Steel
Cement
Power

0.8

0.6

0.4

0.2

0.0
1/1

3/1

5/1

7/1

9/1

11/1

Contribution to SO2 concentration

100%

80%

Public60%

Commerce
Transport
Others40%

Nonferrous
Iron & Steel
Cement

20%

Power

0%
Jan.

Feb. Mar.

Apl.

May Jun.

Jul.

Aug. Sep. Oct. Nov. Dec.