URBAN MORPHOLOGY FOR HOUSTON TO DRIVE MODELS-3/CMAQ AT NEIGHBORHOOD SCALES

摘要

Air quality simulation models applied at various horizontal scales require different degrees of treatment in the specification of the underlying surfaces. As we model neighborhood scales (～1 km horizontal grid spacing), the representation of urban morphological structures (e.g., building and area distributions, and compositional materials for impervious structures such as roads and parking areas) requires much greater detail. At the neighborhood scale, we expect that the heterogeneities of structures within the urban canopy (i.e., the layer between the surface and the tops of the buildings) will exert a strong influence on the urban boundary layer (UBL) wind and thermodynamic structure and a subsequent effect on the pollutant dispersion and resulting air quality predictions. The U.S. EPA Models-3 Community Multi-scale Air Quality (CMAQ) modeling system (Byun and Ching 1999) will be applied at neighborhood scales to drive human exposure models and for human risk assessments purposes (Ching et al. 2000, 2002). CMAQ will be used to support modeling studies and air quality assessments of ozone, particulate matter(PM), and air toxics in Houston, Texas, using the Penn State/NCAR Mesoscale Model (MM5) (Grell et al. 1994) to provide meteorological input. This application requires developing more detailed treatment of the influence of urban structures in MM5 and using additional urban morphological databases as input.