Understanding spatial growth of the old city of Nanjing during 1850–2020 based on historical maps and Landsat data

Abstract

The conservation and renewal of old cities has become one of the focuses of urban planning worldwide. It is crucial for the sustainable development of old cities to expound the growth process of the shape and texture and internal structure of old cities under different political systems from the perspective of spatial configuration. Based on historical maps and Landsat data, using the space syntax theory and GIS platform, this paper studies the urban growth process of the old city of Nanjing for about 170 years since the mid-Qing Dynasty. A finding in this study is that the old city of Nanjing is more capable of north–south growth than east–west growth. During the feudal era from 1850 to 1912, the urban center, population and built-up area of the old city of Nanjing were concentrated in the south of the city. After the founding of the Republic of China in 1912. The built-up area and NAIN core of the old city began to move northward. During the socialist era after 1949, urban growth sped up dramatically. The old city's NAIN core move northward to Xinjiekou-Gulou. This study proves the possibility of using historical maps and Landsat data to study urban growth and builds a framework for the study of the growth of traditional urban spatial forms in history, providing a theoretical reference for the conservation and revitalization of the old city of Nanjing and a method for the study of the spatial forms of other old cities.

Keywords

• Urban expansion
• Historical maps
• Remote sensing images
• Space syntax
• Historical geography