Chinese population geographer
Hu Huanyong imagined the line in 1935 and called it a "geo-demographic
demarcation line". As this line was proposed in 1935, the map of China at the time included
Mongolia (whose independence China did not recognise until after
WWII) but excluded
Taiwan (which was a
colony of
Japan at the time). The origin of the contrast in population density can be found in the favourable climate for agriculture, fertile land and coastal access in eastern China. The oldest cities in China were located in the southeastern and northeastern regions, such as the
Zhongyuan (Central Plains) due to proximity to rivers. The presence of
drainage basins formed by the
Yangtze and
Yellow River improve crop yield, allowing for population increases. Additionally, access to the coast enables overseas trade and allows for economic growth. The most densely populated region, and historical heartland of China is described in the West by the term
China proper due to the dominance of Chinese culture and the
Han Chinese ethnicity throughout the dynasties in contrast with the outer regions. == Demographic trend ==