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)

Species of interest Primary Pollutants: CO NO x SO 2 PM 2.5, PM 10 VOCs Secondary Pollutants O 3 PM 2.5

Current non-attainment designations for San Diego County Pollutant Averaging TimeFederal Standard California State Standard O3O3 1-hrMaintenance areaNon-attainment O3O3 8-hrNon-attainmentNot applicable PM 10 AnnualAttainmentNon-Attainment PM 2.5 AnnualNon-attainmentNot 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% Riverside County25%72%2%1%0% San Diego County (West) 1% 97%1%0% San Diego County (Northeast) 1% 86%12%0% San Diego County (Southeast) 1% 93%4%1% Transportation modeling: Percentage of commuters traveling from home (rows) to work centers (columns)

Total NO x Base Case Emissions

(Shearer et al., 2004)

SpeciesCONO x SO 2 TOG (VOC)PM SourceAreaMobileAreaMobileAreaMobileAreaMobileAreaMobile Coastal Future: 500 k change ,000 k change Example of emissions estimates (tons/day) for existing conditions and the Coastal Future

2003 Coastal Northern Reg. Low Density Three Centers CO Change NO x Change SO Change TOG (VOC) Change PM Change Mobile source emissions estimates (tons/day) for existing conditions and the Alternative Futures

NO x emissions by source category AreaMobile Stationary Biogenic

NO x emissions by scenario with 1,000k new residents CoastalNorthern Regional Low Density Three Centers

MM5 generated one-hour average temperature, wind, and sea- level pressure for July 10, 2003, 10AM -> CAMx

Maximum O 3 for July 10, 2003

O 3 difference distributions by scenario for 1,000k new residents CoastalNorthern Regional Low Density Three Centers

PM 2.5 difference distribution by scenario for 1,000k new residents CoastalNorthern Regional Low Density Three Centers

SimulationsJuly 7July 8July 9July 10July 11 Max O 3 Diff.Max O 3 Diff.Max O 3 Diff.Max O 3 Diff.Max O 3 Diff. Base Case Coastal Future (1,000k) Northern Future (1,000k) Regional Low Density Future (1,000k) Three Centers Futures (1,000k) 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.)

The area will continue to be in violation of the annual Federal PM 2.5 and California 1-hour O 3 standards, and is likely to be in violation of the annual California PM 2.5 and Federal 1-hour O 3 standards. Regulators should focus on reducing primary PM 2.5