Remote Sensing Characterization of the Urban Landscape for Improvement of Air Quality Modeling

The urban landscape is inherently complex and this complexity is not adequately captured in air quality models, such as the Community Multiscale Air Quality (CMAQ) model that is used to assess whether urban areas are in attainment of EPA air quality standards, primarily for ground level ozone. This inadequacy of the CMAQ model, exacerbated by coarse low resolution land cover data inputs, inhibits the model’s ability to make a sufficient response to the heterogeneous nature of the urban landscape. This can impact how well the model predicts ozone pollutant levels over metropolitan areas and ultimately, whether cities exceed EPA ozone air quality standards. We are exploring the utility of high-resolution remote sensing data and urban growth projections as improved inputs to the meteorology component of the CMAQ model focusing on the Atlanta, Georgia metropolitan area as a case study. These growth projections include “business as usual” and “smart growth” scenarios to 2030. The growth projections illustrate the effects of implementing urban heat island mitigation strategies, such as increasing tree canopy and albedo across the Atlanta metro area, with the goal of moderating ground-level ozone and air temperature, compared to “business as usual” simulations in which heat island mitigation strategies are not applied. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the CMAQ modeling schemes. Use of these data has been found to better characterize low density/suburban development as compared with USGS 1km land use/land cover data that have traditionally been used in modeling. Air quality prediction for future scenarios to 2030 is being facilitated by land use projections using a spatial growth model. Land use projections were developed using the 2030 Regional Transportation Plan developed by the Atlanta Regional Commission. This allows the state Environmental Protection agency to evaluate how these transportation plans will affect future air quality and to determine opportunities for State Implementation Plan (SIP) credits. Corresponding author.