Authors: Gang Xu*, Wuhan University, Limin Jiao, Wuhan University
Topics: Urban Geography, Land Use, China
Keywords: urban expansion, population growth, population density, urban density decline
Session Type: Paper
Start / End Time: 10:00 AM / 11:40 AM
Room: Muses, Sheraton, 8th Floor
Presentation File: No File Uploaded
It is widely evident that urban land expansion is faster than population growth, resulting in the decline in urban population densities. But we do not know how urban densities decline over time. Taking 35 major Chinese cities as examples, we found a widespread decline in population densities in China. We proposed an exponential model to quantify the decline in population densities over time in each city from 2001 to 2015. The average adjusted R-square of the exponential model in 35 cities is 0.68, indicating a moderate but acceptable fitting of the temporal variations of densities. The exponential model demonstrates the population density in a city is declining in a constant rate in a certain period, which varies among cities. Apart from Beijing and Shanghai, the fitted annual rates vary from -9 percent to -1 percent with an average of -4.65 percent, which means population densities are declining by 4.65 percent per year in 2001-2015. We further verified the consistency of the exponential rule of decline in urban densities over time (1990, 2000, and 2014) in 200 global cities. Comparatively, the rate of decline in urban densities in Chinese sample cities (-3.6 percent per year, 2000-2014) is faster than that in other countries or regions, such as India (-2.35 percent), Europe (-1.50 percent), and Unites States (-0.78 percent). The persistent decline in urban density highlights the necessity of efficient urban development strategies to slow down its decline and promote compact urban growth.