Using Remote Sensing and Geographic Information Systems to Identify the Underlying Properties of Urban Environments

Urban places represent built environments that are physically distinguishable from the natural environment, and are thus potentially identifiable through the use of remotely-sensed sources such as satellite images. The urban environment can be defined by classifying images and then combining that information with census data to create a quantitative index of the urban-rural continuum. This is based on the premise that variability in the built environment is associated with variability in human behavior, and that this variability captures the nature of urbanness in human societies. The chapter begins with a justification of the use of the built environment as a signature of urban places. It continues with an overview of how satellite images can be used to distill information about the urban environment, and of the role that geographic information systems (GIS) play in the analysis. It then illustrates this approach to understanding the urbanness of places using data from Egypt. Variables derived from satellite images are combined with census data to improve our understanding of the spatial variability in human behavior in the context of the urban-rural continuum. Finally, ways in which this type of analysis could be used to measure and understand phenomena such as urban sprawl and multinucleation of metropolitan areas are suggested.