The dataset of walled cities and urban extent in late imperial China in the 15th–19th centuries

Abstract

Abstract. Long-term urban extent data are highly desirable for understanding urban land use patterns. However, urban observation data based on remote sensing are typically confined to recent decades. In this study, we advance in this arena by reconstructing the walled cities for China that extend from the 15th century to the 19th century based on multiple historical documents. Cities in late imperial China (the Ming and the Qing dynasties, 1368–1911) generally had city walls, and these walls were usually built around the built-up urban area. By restoring the extent of the city walls, it is helpful to explore the urban extent in this period. Firstly, we collected the years of construction or reconstruction of city walls from the historical data. Specifically, the period in which the size of the city wall remains unchanged is recorded as a lifetime of it. Secondly, a specialization on the extent of the city wall could be conducted based on the urban morphology method and a variety of documentation, including the historical literature materials, the military topographic maps of the first half of the 20th century, and the remote sensing images of the 1970s. The correlation and integration of the lifetime and the spatial data led to the creation of the China City Wall Areas Dataset (CCWAD) for the late imperial period. Based on the proximity to the time of most of the city walls, we selected six representative years (i.e., 1400, 1537, 1648, 1708, 1787, and 1866) from CCWAD to produce the China Urban Extent Dataset (CUED) for the 15th–19th centuries. These datasets are available at https://doi.org/10.6084/m9.figshare.14112968.v3 (Xue et al., 2021).