Emerging urban databases for meteorological and dispersion modeling

Mesoscale meteorological codes and transport and dispersion models are increasingly being applied in urban areas. Representing urban terrain characteristics is critical for accurate predictions of air flow, heating and cooling, and airborne contaminant concentrations. We are developing a national database of urban footprints, 'tall building district' footprints, and building statistics. Urban footprints are being derived nationally using a LANL-developed day-night population database. Thresholds in the population dataset that characterize urban areas will be determined using urban footprints derived from high resolution regional landuse datasets. These thresholds will be applied to the national coverage of day-night population to create a national urban footprint dataset. Tall building districts for 46 metropolitan areas in the US having population greater than 500,000 are being digitized from digital orthophotos. In addition, methods are being developed to classify tall building districts using automated analysis of population data, satellite data, and airborne lidar and these approaches will be used in the future to derive a nationally consistent coverage for all metropolitan areas. Statistics of building height, geometry, and density (e.g., mean building height, plan area density, frontal area density, sky view factor) have been computed at 250-m resolution from three-dimensional digital building data for parts of 17 metropolitan areas in the US and are being extrapolated to the 46 highest population metropolitan areas in the US. These three core datasets are being geo-referenced to a geographic coordinate system with the North American Datum 1983, rasterized to 250-m resolution, and packaged for use in typical mapping software (e.g., ArcGIS) for importation to modeling systems. This paper describes on-going development details and current status of these emerging urban databases, outlines future developments, and presents single dataset and integrated database applications.