# Spatial utilization of historical topographic map and its application in land reconstruction of ancient Chinese urban land use

## TL;DR

This study uses historical maps and GIS to reconstruct urban land use in ancient China, revealing regional patterns and core areas of urbanization during the late Qing Dynasty.

## Contribution

A novel method combining historical topographic data and GIS to quantitatively reconstruct ancient urban land use at a high spatial resolution.

## Key findings

- Urban land in late Qing China totaled 1456.015 km², with the highest concentration in Beijing-Tianjin-Hebei and lowest in Qinghai.
- Urban land was heavily concentrated east of the Hu Line, with 87.5% of grids located there.
- Three urban agglomeration cores were identified: North China Plain, Jiangsu-Shanghai-Zhejiang-Anhui, and Sichuan-Chongqing.

## Abstract

The historical topographic map preserves rich geographic information and can provide direct assistance for the reconstruction of various geographic elements. Based on the historical data of cities throughout the Qing Dynasty, the land use scale data of cities across the country was obtained using GIS and urban perimeter conversion models. This study combines city information and city circumference records from the historical maps and archives of the late Qing Dynasty to quantitatively reconstruct the use patterns of ancient China’s urban land at a spatial resolution of 1° × 1°. Uncertainty analysis of the reconstruction results was conducted using modern remote sensing image data as the validation data set. The results showed the following. (1) During the late Qing Dynasty, the total area of urban land in the various provinces and regions was 1456.015 km2. The maximum value was 208.691 km2 in Beijing-Tianjin-Hebei, the minimum value was 1.713 km2 in Qinghai, and the average value was 56.001 km2. (2) The results of grid reconstruction show that among the 398 grids with urban land distribution, the maximum value is 64.099 km2/grid, the minimum value is 0.013 km2/grid, and the average value is 3.658 km2/grid. (3) Of all the grids with urban land, the urban land grid to the west of the Hu Line accounts for 12.5% and the east to 87.5%. (4) During the late Qing Dynasty, urban land use in China was primarily concentrated in agriculturally developed areas such as the North China Plain, the Central Plains, Jiangnan, and the Sichuan-Chongqing region. (6) The results of a kernel density estimation showed that there were obviously three core areas of urban land agglomeration in China during the late Qing Dynasty: the North China Plain-Central Plains, the Jiangsu-Shanghai-Zhejiang-Anhui area, and the Sichuan-Chongqing urban core area. This study provides basic data for urban land use during historical periods and provides a basis for the quantitative reconstruction of relevant urban land data for historical archives.