WRAP RMC Phase II Wind Blown Dust Project
ENVIRON International Corporation
and
University of California, Riverside
August 24, 2004
Phase I Project Summary• Objectives
– Develop general methodology based on ‘MacDougall Method’ – Develop 1996 gridded PM inventory of WB Dust for the
Western States
• Limitations– Threshold surface friction velocities– Emission factors– Vacant land stability– Dust reservoirs– Rain events– Vegetation density
Phase II Project Background
• Develop improved general methodology based on Phase I recommendations and recent literature review
• Update gridded PM inventory of WB Dust for 2002 using the Inter-RPO regional modeling domain
• Develop of surface friction velocities and threshold friction velocities
• Develop improved emission flux relationships
• Improve vacant land characterization– Disturbance– Land use type– Reservoirs
• Conduct model performance evaluation
Revised methodology to consider:
• Threshold velocities• Emission factors• LULC and Soil characteristics• Reservoir characteristics• Agricultural adjustments
• Full presentation from DEJF Meeting in Reno at http://64.27.97.126/forums/dejf/meetings.html
Dust Category 3 4 6 7
Land use Ag. Grass Shrubs Barren
Surface roughness (cm) 0.031 0.1 0.05 0.002
Threshold friction Velocity (mile/h) 8.33 13.81 9.62 6.81
Threshold wind velocity at 38m height (mile/h) 29.50 44.25 32.75 28.50
Characteristics of Dust Categories
Model Sensitivity Simulations
• Run a :
– No limitation on dust event duration
– All soils considered loose undisturbed
• Run b :
– Dust events limited to 10 hrs/day
– All soils considered loose undisturbed
Model Sensitivity Simulations
• Run c :
– No limitation on dust event duration – Assume 10% of barren, grass & shrublands area is disturbed– Threshold velocity for grass & shrublands = 0.5 * undisturbed value– Threshold velocity for barren lands = .27 * undisturbed value
• Run d :– Dust events limited to 10 hrs/day for undisturbed soils– Assume 10% of barren, grass & shrublands area is disturbed– Threshold velocity for grass & shrublands = 0.5 * undisturbed value– Threshold velocity for barren lands = .27 * undisturbed value
Model ResultsScenario a: no limit on duration; all soils loose, undisturbed
Dust emissions, Scenario a
62.50%
17.24%
19.38%
0.88%
Dust code 3
Dust code 4
Dust code 6
Dust code 7
Model ResultsScenario b: event duration <=10 hrs/day; all soils loose, undisturbed
Dust emissions, Scenario b
63.83%
15.32%
19.92%
0.93%
Dust code 3
Dust code 4
Dust code 6
Dust code 7
Model ResultsScenario c: no limit on duration; assume 10% disturbed area for grass,
shrub, barren lands
Dust emissions, Scenario c
50.29%
24.82%
22.95%
1.94%Dust code 3
Dust code 4
Dust code 6
Dust code 7
Model ResultsScenario d: event duration <= 10hrs/day for disturbed soils; assume 10%
disturbed area for grass, shrub, barren lands
Dust emissions, Scenario d
44.35%
27.75%
25.33%
2.58%
Dust code 3
Dust code 4
Dust code 6
Dust code 7
Dust Totals for WRAP Statestons/year
Scenario WRAP States Domain Total (US only)
a 2,222,219 9,451,368
b 1,310,120 5,228,818
c 3,077,196 11,098,731
d 2,165,096 6,876,180
1996 Results 2,240,288 4,366,907
Annual PM10 for WRAP States
Dust Yearly Total by StateWRAP States
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
scen a
scen b
scen c
scen d
1996
Annual PM10 for the Western States
Dust Yearly Total by StateWestern States
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
AZ
AR
CA
CO ID IA KS
LA
MN
MO
MT
NE
NV
NM ND
OK
OR SD
TX UT
WA W
I
WY
State
Ton/
y
scen a
scen b
scen c
scen d
1996
Comparison of Monthly Dust Emissions
Monthly Dust Emissions for the Entire Domain
0.0
400000.0
800000.0
1200000.0
1600000.0
2000000.0
2400000.0
2800000.0
1 2 3 4 5 6 7 8 9 10 11 12
month
Ton/
Mon
th
scen a
scen b
scen c
scen d
Dust from Category 3 (Ag land)PM10 Yearly Total
0
50000
100000
150000
200000
250000
300000
350000
400000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
scen a
scen b
scen c
scen d
Annual PM10 from Ag Land for WRAP States
Dust from Category 4 (Grass land)PM10 Yearly Total
0
40000
80000
120000
160000
200000
240000
280000
320000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
scen a
scen b
scen c
scen d
Annual PM10 from Grass Land for WRAP States
Dust from Category 6 (Shrub land)PM10 Yearly Total
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
scen a
scen b
scen c
scen d
Annual PM10 from Shrub Land for WRAP States
Dust from Category 7 (Barren land)PM10 Yearly Total
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
scen a
scen b
scen c
scen d
Annual PM10 from Barren Land for WRAP States
Dust from all Categories for Scenario dPM10 Yearly Total
0
30000
60000
90000
120000
150000
180000
210000
240000
AZ
CA
CO ID MT
NV
NM ND
OR SD
UT
WA
WY
State
Ton/
y
Cat. 3
Cat. 4
Cat. 6
Cat. 7
Scenario d Annual PM10 from All Dust Categories for WRAP States
2002 Annual PMC Scenario a: no limit on duration; all soils loose, undisturbed
2002 Annual PMC Scenario b: event duration <=10 hrs/day; all soils loose, undisturbed
2002 Annual PMC Scenario c: no limit on duration; assume 10% disturbed area for grass,
shrub, barren lands
2002 Annual PMC Scenario d: event duration <=10 hrs/day; assume 10% disturbed area for
grass, shrub, barren lands
Model Performance Evaluation• Evaluate model results for reasonableness and accuracy
• Compare predicted WB dust emissions near IMPROVE monitors with measured IMPROVE dust extinction (Bdust)
• Enhancements to CMAQ to track WB and other dust
• Evaluate model CMAQ model performance with and with out WB dust emissions
• Refined model performance evaluation using results of Etyemezian, et al.
• For events characterized as wind blown dust events, determine whether dust model predicts impacts
Model Performance EvaluationSchedule
• Initial Model Performance Evaluation Report:
August 31, 2004
• Refined Model Performance Evaluation Report:
October 31, 2004
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