M. Ramsey, Department of Geology and Planetary Science, 321 Old Engineering Hall, University of Pittsburgh, Pittsburgh, PA 15260, USA, (412) 624-1408

As the global population expands, concentrating in the large urban centers of the world, the stress placed on the local environment will also magnify. Not since the Industrial Revolution has the world experienced such urbanization. In the next 25 years, estimates place nearly two-thirds of the population (over 5 billion) in cities. A vast majority of the fastest growing urban centers are located in coastal and semi-arid environments, and are therefore vulnerable to natural hazards and ecological degradation. Because of these predictions and the current urban expansion, there is now an equally strong growth in the science of the urban landscape. For example, the NSF awarded the first ever urban Long- Term Ecological Research (LTER) projects to Phoenix, AZ and Baltimore, MD in 1997. NASA is also currently funding research into natural hazard mitigation within the urban environment, in addition to a dedicated monitoring program with the recently-launched ASTER instrument on the Terra spacecraft. Remote sensing of urban environments has been limited in the past due to the low spatial resolution of most satellite-based instruments, as well as the lack of demand/use from city officials, planners, and scientists. However, ASTER data will be valuable because of the high spatial resolution (15-90 m/pixel), the multispectral coverage (visible - thermal wavelengths), and the ability to generate along-track high resolution DEMs critical for urban topographic analysis. By June of 2000, ASTER is scheduled to enter its nominal mapping phase, which is planned to continue for six years.

ASTER urban data is scheduled to be captured two times per year over 100 of the largest cities, with emphasis on those currently experiencing fast growth rates and environmental hazards. The urban monitoring will focus on cities in semi-arid environments and will demand dedicated data processing and dissemination to local governments. The primary goal of ASTER's UEM program is to ensure these data are acquired, processed and made available to scientists and local officials working in these cities. The planned products are calibrated and geometrically accurate land use change, material identification, and heat island maps. Current algorithm development and testing is ongoing at both urban LTER sites using a combination of Landsat Thematic Mapper data and NASA airborne sensors. These products form an integral part of the ecological modeling ongoing at the Phoenix LTER and are being used in new ways to examine urban hazard mitigation such as the detection of fire scars and their relationship to localized flooding.

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Invited: American Geophysical Union Spring Meeting
Date: May, 2000