Methodology matters: measuring urban spatial development using alternative methods

摘要

The effectiveness of policies implemented to prevent urban sprawl has been a contentious issue among scholars and practitioners for at least two decades. While disputes range from the ideological to the empirical, regardless of the subject of dispute, participants must bring forth reliable data to buttress their claims. In this study we discuss several sources of complexity inherent in measuring sprawl. We then exhibit how methodological decisions can lead to disparate results regarding the quantification and characterization of sprawl. We do so by employing three GIS-based methods for quantifying the amount and defining the configuration of land-cover change from open to built space in a 350 km~2 area in central Israel over a five-year period. We then calculate values for a variety of spatial indices commonly associated with urban sprawl. Our results reveal that some urban growth patterns are so robust that multiple methods and indices yield similar results and thus lead to similar conclusions. However, we also note that many divergent and even contradictory results are produced depending on the measurement method used and the index selection.