Determining Alternative Futures - Urban Development Effects on Air
Quality
Julide Kahyaoglu-Koracin and Darko Koracin
May 2007
Zagreb, Croatia
Objectives
•Evaluate the impact of the four alternative futures on air quality in Southwest California
•Develop a modeling system to integrate projected land use patterns with atmospheric emissions and secondary pollutants, meteorology and dispersion, and transportation
•Provide an assessment of the likelihood that San Diego County will violate various Federal and California Standards
Framework for the assessment of air quality using an alternative futures methodology (Mouat et al., 2004)
Total Emissions
BiogenicEmissions
Area SourceEmissions
AirQuality
ProcessModels
ExistingConditions
AirChemistry
MobileSource
Emissions
FutureAir
Quality
PotentialFutureConditions
PotentialFutureConditions
ExistingConditions
&Policies
ExistingConditions
&Policies
ExistingLand Cover
And Infrastructure
AvailableLand
&Policies
AvailableLand
&Policies
Change inPopulation
Values & Views
Change inPopulationChange inPopulation
Values & ViewsValues & Views
FutureLand Cover
AndInfrastructure
XX
YY
AirQuality
ImpactonFutureConditions
ImpactonFutureConditions
Total Emissions
Future Total Emissions
Species of interestPrimary Pollutants:CONOx
SO2
PM2.5 , PM10
VOCs
Secondary PollutantsO3
PM2.5
Current non-attainment designations for
San Diego County
PollutantAveraging Time Federal Standard
California State Standard
O3 1-hr Maintenance area Non-attainment
O3 8-hr Non-attainment Not applicable
PM10 Annual Attainment Non-Attainment
PM2.5 Annual Non-attainment Not yet designated
Major commuting zones and associated work centers
Orange and Los Angeles Counties
Riverside County
San Diego
County (West)
San Diego
County (NE)
San Diego County
(SE)
Orange and Los Angeles Counties
97% 2% 1% 0% 0%
Riverside County 25% 72% 2% 1% 0%
San Diego County (West)
1% 1% 97% 1% 0%
San Diego County (Northeast)
1% 1% 86% 12% 0%
San Diego County (Southeast)
1% 1% 93% 4% 1%
Transportation modeling: Percentage of commuters traveling from
home (rows) to work centers (columns)
Total NOx Base Case Emissions
(Shearer et al., 2004)
Species CO NOx SO2 TOG (VOC) PM
Source Area Mobile Area Mobile Area Mobile Area Mobile Area Mobile
2003 6.92 1817.14 2.63 220.21 0.029 12.08 82.47 193.79 287.08 6.06
Coastal Future: 500 k 7.25 1968.83 3.26 233.00 0.033 12.16 87.84 207.62 287.16 6.99
change 0.26 151.69 0.63 12.80 0.004 0.08 5.37 13.82 0.08 0.93
1,000 k 7.50 2152.46 3.89 247.27 0.037 12.27 93.21 220.32 287.24 8.04
change 0.51 335.32 1.26 27.07 0.008 0.19 10.74 26.53 0.17 1.98
Example of emissions estimates (tons/day) for existing conditions and the Coastal Future
2003 Coastal NorthernReg. Low Density
Three Centers
CO 1817.14 2152.46 2165.20 2145.28 2144.09
Change 335.32 348.06 328.14 326.95
NOx 220.21 247.27 249.21 247.33 247.00
Change 27.06 29.00 27.12 26.79
SO2 12.08 12.27 12.27 12.26 12.26
Change 0.19 0.20 0.19 0.19
TOG (VOC)
193.79 220.32 222.44 223.89 221.36
Change 26.53 28.65 30.10 27.57
PM 6.06 8.04 8.26 8.38 8.14
Change 1.98 2.20 2.32 2.08
Mobile source emissions estimates (tons/day) for existing conditions and the Alternative Futures
NOx emissions by source category
Area Mobile
Stationary Biogenic
NOx emissions by scenario with 1,000k new residents
Coastal Northern
RegionalLow Density
ThreeCenters
MM5 generated one-hour average temperature, wind, and sea-level pressure for July 10, 2003, 10AM -> CAMx
-118.4 -118 -117.6 -117.2 -116.8 -116.4 -116 -115.6
Peak O zone (ppb) Base C ase - Ju ly 10
32.2
32.4
32.6
32.8
33
33.2
33.4
33.6
33.8
34
34.2
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
Maximum O3 for July 10, 2003
O3 difference distributions by
scenario for 1,000k new residents
Coastal Northern
RegionalLow Density
ThreeCenters
PM2.5 difference distribution by
scenario for 1,000k new residents
Coastal Northern
RegionalLow Density
ThreeCenters
Simulations July 7 July 8 July 9 July 10 July 11
Max O3
Diff. Max O3
Diff. Max O3
Diff. Max O3
Diff. Max O3
Diff.
Base Case 115 - 132 - 129 - 135 - 121 -
Coastal Future (1,000k)
128 13 134 2 136 7 143 8 128 7
Northern Future (1,000k)
138 23 134 2 142 13 146 11 133 12
Regional Low Density Future (1,000k)
150 35 134 2 142 13 146 11 137 16
Three Centers Futures (1,000k)
139 24 134 2 141 12 146 11 134 13
Predicted maximum ozone (ppb) values for five simulations and episode days
Summary
The addition of 500k or 1,000k residents to the study area appears to have a greater overall impact on air quality than does their distribution.
Nevertheless the resultant differences in human activity influence air quality.
The project developed a modeling system to predict air quality based on changes in land use patterns resulting from development and growth
• The system coupled land-use predictions with transportation, emissions, meteorology, dispersion, and transportation models.
• This tool can allow potential users to evaluate and assess other “least likely impacts” stemming from the impacts of future growth.
Summary (cont.)
Summary (cont.)
•The area will continue to be in violation of the annual Federal PM2.5 and California 1-hour O3
standards, and is likely to be in violation of the annual California PM2.5 and Federal 1-hour O3 standards.
•Regulators should focus on reducing primary PM2.5