DEFINING BUILT-UP AREA USING URBAN ATLAS MAPS CASE OF PRAGUE

Built-up area of cities is the base-component for spatial planning. However, there is no agreement on one method how to define it. In general, there are two common ways on how it is being defined. First is based on administrative boundary of the developed part of a municipality. The other commonly used method determines the built-up area on the basis of real physical structures in the city. While the former is easy to delineate, yet it is not very useful for urban analysis and planning as it often doesn't reflect the real built-up area. The latter, on the other hand, does and as such it fits the needs of planning more. The issue is, however, which maps are the most appropriate to derive it from; i.e. which are the most often updated and accurate enough to provide relevant results, and has wide enough coverage globally to allow for grounded comparisons between cities. Our assumption that Urban Atlas (UA), which is planned to be updated every three years, and to cover 362 cities from 31 countries, would cover the above mentioned criteria. Accuracy of the maps still remains the issue. The aim of this article is therefore to verify the relevance of UA maps for built-up area determination, primarily pointing out the accuracy of the maps. In order to achieve this aim, UA technical parameters are discussed in the article. Built-up area based on the data from UA is determined, and compared with that based on the Digital maps of Prague and with a site survey on three different city structures. The first structure represents a central-city, the second is at an urban-edge, and the third is rather a periphery. Finally, the accuracy of UA in these case studies is assessed, and the suitability of UA for determination of built-up area worldwide is being discussed.