Analyzing Population Density Disparity in China with GIS-automated Regionalization: The Hu Line Revisited

Abstract

The famous 'Hu Line', proposed by Hu Huanyong in 1935, divided China into two regions (southeast and northwest) of comparable area size but drastically different in population. However, the classic Hu Line was derived manually in absence of reliable census data and computational technologies of modern days. It has been subject to criticism of lack of scientific rigor and accuracy. This research uses a GIS-automated regionalization method, termed REDCAP (Regionalization with Dynamically Constrained Agglomerative Clustering and Partitioning), to reconstruct the demarcation line based on the 2010 county-level census data in China. The results show that the logarithmic transformation of population density is a better measure of attributive homogeneity in derived regions than density itself, and produces two regions of nearly identical area size and greater contrast in population. Specifically, the revised Hu Line by Hu Huanyong in 1990 had the southeast region with 94.4% of total population and 42.9% of total land, and our delineation line yields a southeast region with 97.4% population and 50.8% land. Therefore, the population density ratio of the two regions is 27.1 by our line, much higher than the ratio of 22.4 by the Hu Line, and thus outperforms the Hu Line in deriving regions of maximum density contrast with comparable area size. Furthermore, more regions are delineated to further advance our understanding of population distribution disparity in China.

Population distribution patterns and changes in China 1953–2010

“…By extension, population density varies exponentially across space. Therefore, population density in logarithm was used to measure attributive homogeneity in implementing the REDCAP regionalization method (Wang et al, 2019). As shown in Figures 6a-6f, all six REDCAP-derived lines were largely consistent with the Hu Line and relative stable over time.…”

Uncertainty Analysis of Premature Death Estimation Under Various Open PM2.5 Datasets

“…The Yangtze River Delta Urban Agglomerations, the urban agglomeration in the middle reaches of the Yangtze River, and other regions, which were located in the east of the Hu Line, were agglomeration areas of cities with high levels of PM 2.5 pollution (Shen L. et al, 2021). As an important agglomeration area of population and economy in China, the population in this area reaches 1.2 billion, accounting for 94% of the country (Wang et al, 2019). Therefore, the study area is defined as the mainland of eastern China below the Hu line (excluding Heilongjiang Province, Hong Kong, Macao, and including Ningxia Hui Autonomous Region) and includes 19 provinces, four central government-controlled municipalities, and two autonomous regions, all referred to here as provinces (Figure 1).…”

Decomposition of Water Footprint of Food Consumption in Typical East Chinese Cities

“…China's population is denser in the eastern coastal cities, taking the Hu Line as the population boundary [38]. Benefiting from early reform and opening policy, cities developed rapidly and gradually formed the Beijing-Tianjin-Hebei urban agglomeration, the Yangtze River Delta urban agglomeration, and the Guangdong-Hong Kong-Macao Greater Bay Area, which included the political and economic centers of China (Beijing and Shanghai, respectively).…”