Identifying urban boundaries: application of remote sensing and geographic information system technologies

This paper focuses on a new definition of urbanization trends by investigating the concept of a fuzzy urban boundary (UB) that assigns different membership levels to urbanized aggregates based on a proposed composite index. The research work builds on this logic to investigate a new approach in defining urbanized areas by compounding the characteristics of the fuzzy density of an urban agglomeration with land use variation and intensity of economic activity. Spatial overlaying capabilities of geographic information system (GIS) are used to model the urbanization trend in the case study of Greater Beirut. The UB is defined using a multispectral high resolution visible (HRV) Satellite Pour L'observation de la Terre (SPOT) satellite image. The challenges of urban modelling using satellite images are addressed through an investigative approach in cartographic feature extraction and delineation of the urban agglomeration. This entails image treatment of the spot HRV image, defining internal characteristics of the urban agglomeration and constructing spatially continuous socio-economic data sets that can be combined with the digital remotely sensed image.Key words: fuzzy logic, GIS, remote sensing, spatial urban modelling, urban boundary, urbanization trends.