Measuring the superblock based on a hierarchy matrix of geometry, configuration, network, and area: The case of Nanjing

A superblock is a core unit of the built form of an old city in China, in which various morphological elements are organized and related through a hierarchical structure. Existing quantitative studies are generally limited to a single perspective or object and do not support the classification of morphological types through comprehensive analysis methods. In this study, a new cognitive framework, the hierarchy matrix, is presented to bridge this knowledge gap. It consists of four dimensions: configuration of network, geometry of network, configuration of area, and geometry of area. These dimensions are formed by the intersection of the two coordinates of perspective and object. Based on their measurement, the overall characteristics of the superblocks are represented and compared through matrix diagrams. Subsequently, the validity and adaptability of this quantitative approach are verified through an empirical analysis of Nanjing’s old city superblocks. The results reveal the morphological type of superblocks, and their causes are analyzed through the correlation with the urban environmental background. hierarchy matrix is potentially a useful method for studying the complex emerging built form of rapidly changing cities, especially in developing countries, such as China. The hierarchical matrix method is not only an analysis tool but also has the potential to develop an evaluation method to provide scientific support for the practice of urban renewal.