From design to digital model: A quantitative analysis approach to Garden Cities theory

As a complement to the development of new theories, the reevaluation and knowledge mining of classical theories can be beneficial for urban development. In particular, quantitative analyses for cities can now take advantage of geographic information systems (GIS). Proposed more than one hundred years ago, Ebenezer Howard's Garden City is a generally acknowledged classical urban theory. On the basis of the original work, we model a digital Garden City in ArcGIS. The model is accurate to within 1% for both areal and length measures, and enables our further quantitative evaluation of the urban land-use structure and open green space accessibility. We then compare the classical theory with a modern-built area for the quantitative evaluation results. Zhujiajiao Town in Shanghai, winner of the International Award for Livable Communities in 2008, provides a reference. Although the central areas of Garden City and Zhujiajiao Town have different geographical and historical backgrounds, the measured land-use structures, including indicators of area proportion and area per capita, exhibits similarities on land-use types of residential, transportation, and ecological conservation, which offer a considerable reference for land-use structure of a livable urban area. Comparison of the accessibility to open green spaces in both cities shows that the average access time from a residential area to open green space in Garden City is just 186.77 s, which is much shorter than that in Zhujiajiao. Our research shows that the classical Garden City theory can be modeled into highly accurate digital forms, allowing richer information in quantitative terms to be obtained than from the original theory, and enabling comparisons with modern cities. Besides, the proposed digital modeling approach is widely applicable to classical theories and historical planning cases.