# Spatiotemporal Analysis of Urban Expansion in Beijing, China
###### Abstract  
Using Landsat TM/OLI remote sensing images and social statistical data from 1995, 2000, 2005, 2010, 2015, and 2020, construction land information in Beijing's main urban area was extracted with ArcGIS 10.4.1 and other software. Based on calculations of the expansion speed, expansion intensity, fractal dimension, and elasticity coefficient, the spatiotemporal expansion characteristics of the urban area of Beijing were analyzed to reveal the laws and driving forces of urban expansion in Beijing. The results showed that the urban construction land area in Beijing expanded by a factor of 0.53 from 1995 to 2020, and its expansion speed and intensity gradually slowed. The overall expansion trend is that the central urban area remains basically unchanged, while the peripheral areas are rapidly expanding, showing a trend of rapid growth first and then stable growth, and the urban layout is basically stable. The urban expansion of Beijing has led to increasingly complex, tortuous, and unstable boundaries. Overall, the center of gravity of Beijing is moving toward the northeast, and the elasticity coefficient of urban expansion is 1.67 times that of a reasonable coefficient. The intensity and direction of urban expansion in Beijing are most significantly related to population mobility. Research on the expansion of Beijing lies the foundation for the integration and coordinated planning of resources in the various districts of Beijing and provides a basis for its sustainable development. urban expansion; urban construction land; Beijing; driving factors +
Footnote †: journal: Medical  
negative impact of urban resources on urban population density is weakening [8]. Urban location has a positive impact on urban population density. Meanwhile, urban spatial expansion is an important dimension of comprehensive urban expansion [9]. The industrial structure has a negative impact on urban spatial expansion, while the supply of natural resources has a positive impact on urban spatial expansion. The level of urban public finance expenditure has a positive promoting effect on urban spatial expansion [10]. On the other hand, urban economic growth has a significant positive impact on factors such as industrial structure, resource supply, and public financial expenditure. Since the 1990s, China's urbanization has accelerated, the phenomenon of urbanization has gradually emerged, and the urban system has gradually improved. At the beginning of the 21 st century, as we entered a period of accelerated development, we began to expand on a large scale, with an increasing amount of urban construction land and a decreasing amount of available land. Moreover, with the acceleration of urbanization and the continuous expansion of urban scale, problems such as shortages of arable land resources, declines in per capita ecological space, traffic congestion, environmental degradation, and urban heat island effects are becoming increasingly prominent, gradually affecting the living conditions of residents and the urban environment. With the continuous process of opening up to the outside world, the increasing number of foreign exchanges in Beijing, and the acceleration of modernization, it is proposed that Beijing be built into an international metropolis. Beijing, as China's political and cultural center, international communication center, and financial management center, is an important gateway for China's development. Since the 1990s, the urban scale of Beijing has rapidly expanded, with the built-up area continuously expanding and the population skyrocketing. It is also concentrated in the main urban area, where the number of motor vehicles has doubled. This has brought enormous pressure to urban resources, the environment, transportation, and daily operations. If this area is not controlled and continues to expand in a simple and disorderly manner, this will be detrimental to the sustainable development of Beijing.