Reducing Air Pollution In Los Angeles

1
CALCULATING FUGITIVE DUST EMISSIONS FROM WIND
EROSION

• Mohammad Omary CERT, UCR
• Gerard Mansell ENVIRON
• Martinus Wolf ERG
• Michael Uhl DAQM, Clark County, NV Bill Barnard
  MACTEC Engr. Consulting
• Jack Gillies DRI

2
OUTLINE

• Project Background Overview
• Data Sources
• Estimation Methodology
• Agricultural And Urban Considerations
• Program Development
• Summary

3
BACKGROUND AND OVERVIEW OF PROJECT

• Overall Objective to Compile PM10 and PM2.5
  Emission Factors and Inventories From Windblown
  Dust for the Western Region of the US
• Develop Integrated SMOKE Processing Modules for
  PM10 and PM2.5 Emissions Modeling

4
DATA SOURCES

• Land Use/Land Cover
• Biogenic Emission Landcover Database (BELD3)
• North American Land Cover Characteristics (NALCC)
• Soils Characteristics
• State Soil Geographic Database (STATSGO)
• Soil Landscape of Canada (SLC_V2)
• International Soil Reference and Information
  Center
• Meteorological Data
• 1996 MCIP/MM5, 36-km

5
DATA COMPILATION FOR LAND USE AND SOIL TYPES

• Land Use and Soil Types data Were Compiled from
  1km grid into 12km grid.
• Each 12km cell Has One or More Area Fractions for
  Different Land Use
• Soil Type of 12km Cell Was Set as the Dominant
  Soil Type from the 1km Cells

6
MAJOR LAND USE

• Urban Stable/Unstable
• Agriculture Stable with Ag. Adjustments
• Shrub/Grassland Stable
• Forest Stable
• Barren Unstable

7
WIND TUNNEL STUDY RESULTS THESHOLDS
(Gillette et al., 1980 Gillette et al., 1982
Gillette, 1988 Nickling Gillies, 1989)
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WIND TUNNEL STUDY RESULTSEMISSION FACTORS
9
STANDARD SOIL TETURE TRIANGLE
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MAJOR SOIL TYPES

• For the Purpose of Developing Emission Factors,
  Standard Soil Types Were Divided Into Five Major
  Soil Types
• Silty Sand Clay
• Sandy Silt
• Loam
• Sand
• Silt

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SOIL TEXTURE MAPPING
STATSGO Soil Texture Soil Texture Code Soil Group Code
No Data 0 0
Sand 1 4
Loamy Sand 2 4
Sandy Loam 3 2
Silt Loam 4 1
Silt 5 5
Loam 6 3
Sandy Clay Loam 7 2
Silty Clay Loam 8 5
Clay Loam 9 3
Sandy Clay 10 2
Silty Clay 11 5
Clay 12 1
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EMISSION RATES BY SOIL GROUP FOR STABLE SOILS
0.035
0.03
0.025
Soil Group 1
Soil Group 2
0.02
Soil Group 3
Emission Factor (ton/acre/hour)
Soil Group 4
0.015
Soil Group 5
0.01
0.005
0
20 - 24.9
25 - 29.9
30 - 34.9
35 - 39.9
40 - 44.9
45 - 49.9
50 - 54.9
10-m Wind Speed (mph)
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EMISSION RATES BY SOIL GROUP FOR UNSTABLE SOILS
0.03
0.025
0.02
Soil Group 1
Soil Group 2
0.015
Soil Group 3
Emission Factor (ton/acre/hour)
Soil Group 4
Soil Group 5
0.01
0.005
0
20 - 24.9
25 - 29.9
30 - 34.9
35 - 39.9
40 - 44.9
45 - 49.9
50 - 54.9
10-m Wind Speed (mph)
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METEOROLOGY

• Meteorological Data Were Compiled from MM5 and
  MCIP for 36km Cells. The Data Needed Were
• Snow Cover
• Rain Occurrence
• Surface Temperature
• Wind Velocity at 10m Height

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VEGETATION COVER CONSIDERATIONS
Land Use Category Vegetation Cover Reduction Factor
Urban 55 (stable), 0 (Unstable) 0.0701 1
Agriculture ---- ----
Shrubs 11 0.700
Grass 23 0.195
Forrest 55 0.0701
Barren 0 1
Desert 0 1
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AG. CONSIDERATIONS

• Non-Climatic Factors Significantly Decrease Soil
  Loss From Agricultural Lands
• Seven Adjustment Factors Simulate These
  Effects
• Bare soil within fields
• Bare borders surrounding fields
• Long-term irrigation
• Crop canopy cover
• Post-harvest vegetative cover (residue)
• Post-harvest replanting (multi-cropping)
• Tillage

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URBAN CONSIDERATIONS

• Urban Cells or Area Fraction from 12km Cell Split
  Into
• Core urban 91.667
• Boundary urban 8.333
• Core Urban Area Considered As
• Stable soil 92
• Unstable soil 8
• Boundary Urban Area Considered As
• Stable soil 70
• Unstable soil 30

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EMISSIONS ESTIMATION METHODOLOGY

• No Emissions for 72 h After Snow Melt
• No Emissions for 72 h After Rain Event
• No Emissions for 12 h After Surface Freeze
• No Emissions for Wind Speed Less Than 20mph

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EMISSIONS ESTIMATION METHODOLOGY contd

• For Stable Soils
• Apply emission rates for the first hour only
  during a wind event
• Apply emission spike at the first hour
• Wait 24 hours before applying emission rates or
  emission spikes

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EMISSIONS ESTIMATION METHODOLOGY contd

• For Un-Stable Soils
• Apply emission rates for the first 10 hours only
  during a wind event
• Apply emission spike at the first hour
• Wait 24 hours before applying emission rates or
  emission spikes

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GENRAL INPUT DAT

• Daily/Hourly Meteorological Data
• State/County, Crop Management Zone, and Soil
  Type, For Each 12km Cell.
• Area fractions For Each 12km Cell, and Land Use
  For Each Area Fraction.
• Emission Rates and Emission Spike For The Wind
  Categories

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AGRICULTURAL INPUT DAT

• Ag. Area Fractions (Barren, Border, Crop)
• Lon Term Irrigation Factors For Each Soil Type
• Irrigation Fractions For Each County And Crop
• Tillage Fractions For Each County And Crop
• Planting And Harvesting Date For Each Crop and
  Crop Management Zone

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AGRICULTURAL INPUT DAT, contd

• Crop Canopy Factors For Each Crop
• Irrigation Fractions For Each County And Crop
• Tillage Fractions For Each County And Crop
• Planting And Harvesting Date For Each Crop and
  Crop Management Zone

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SOURCE OF AG. ADJUSTMENT FACTORS

• Crop calendars with growth curves from Revised
  Universal Soil Loss Equation (RUSLE2) model
• Residues remaining after harvest due to
  conservation tillage practices from Purdues
  Conservation Technology Information Center (CTIC)
• Irrigation events from crop budget databases

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COMPUTER PROGRAM FLOW CHART
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A 36 km Cell Divided into 12 km Cells and Area
Fractions
36 km
AF1
AF2
12 km
AF3
12 km
36 km
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START
Julian Day Time
Next I36,J36 Cell
Cell I36, J36
Snow cover, Surface temp, Rain, Wind velocity
Met Data
Yes
Snow cover
DUST36 0
No
Yes
Surface temp lt0C
DUST36 0
No
Next I36,J36 Cell
Next Time Step
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Yes
Rain
DUST36 0
No
T no rain gt72h or T no snow cover gt 72h
or T surface temp above 0C gt 12h
No
DUST36 0
Yes
No
Wind velocity gt minimum velocity
DUST36 0
Next I36,J36 Cell
Yes
Next Time Step
29
Map I36, J36 to I12 and J12 (9 cells)
Next I12,J312 Cell
Loop over I12,J12 cells
No
Soil Group is Defined
DUST12 0
Yes
Read Land Use Codes (LUCDAF ), and Area Fractions
(AF)
Next AF
Loop over Area Fractions
Next I12, J12 Cell
Next I36,J36 Cell
Next Time Step
30
Is the land use water, wet
land etc.
Yes
DUSTAF 0
No
Next AF
No
Is the time since the end of the last wind event
gt 24h
DUSTAF 0
Yes
Yes
No
Is the soil disturbed?
Next AF
Next I12, J12 Cell
Next I36,J36 Cell
Next Time Step
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Next I12,J12 Cell
Next AF
Yes
No
Is it the first hour of the
wind event
No
No
Is the wind event gt 10h
DUSTAF 0
Yes
Select the proper emission rate and calculate the
dust emissions (DUSTAF)
Is the AF an Ag land?
No
Yes
Divide the AF into CropAF, BareAF, BordAf
Apply vegetation cover reduction factors
Next I36,J36 Cell
DUST12DUST12 DUSTAF
Next Time Step
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Apply AG Factors 1-No adjustment to
BordAF 2-Apply long term irrigation factor to
BareAf 3-Apply long term irrigation, tillage,
crop canopy, and post harvest residue factors to
CropAf
DUST12 DUST12 DUSTAF
Next AF
DUST12 DUST12 AGF
Next I12,J12 Cell
DUST36 DUST36 DUST12
Next I36,J36 Cell
Next Time Step
END
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Yes
No
Next AF
Is it the first hour of the
wind event
No
Is the wind event gt 10h
No
DUSTAF 0
Yes
Select the proper emission rate and calculate the
dust emissions (DUSTAF)
Is the AF an Ag land?
No
DUST12DUST12 DUSTAF
Yes
Next I12,J12 Cell
Next I36,J36 Cell
Divide the AF into CropAF, BareAF, BordAf
Next Time Step
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TOTAL MONTHLY EMISSIONS (tonnes)
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TOTAL MONTHLY DUST (tonnes)
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ANNUAL EMISSION BY LANDUSE (tonnes)
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SUMMARY

• The Fugitive Dust Was Considered As PM10
• The PM10 Was Split Into 22 PM2.5 and 78 PMC
• Most Of The Dust From Desert And Grass/Shrub Land
  
• The Ag Adjustment Ranges From 10-90, With
  Yearly Average 40

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Future Work

• Dust Event After Rain, Snow Melt Can Be Improved
  By Taking In Consideration, Season, Soil Type,
  And Rain Depth
• Use Of Smaller Grid Size for Met Data.
• Use GIS to develop gridded Soil Type and Land Use
  for other model domain and grid definitions.

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