A study on the interaction and evolution of the spatial expansion and administrative division adjustment in Beijing metropolitan area

Since 1990s and especially since 2000, the city space of Beijing has grown rapidly. There's no doubt that the urban construction land area is expanding to the suburban areas, which is the result of rapid social and economic growth in the city and also closely related to the reform of "turning county into district". In other words, the adjustment of administrative division in Beijing interacts with the expansion of urban construction land space. Beijing turns counties into districts and introduces regional offices are two distinct evidence. As for the interaction, there're both advantages and disadvantages and the focus of the article is to explore how to exploit the favorable conditions and avoid unfavorable ones. The article takes the town administrative region as the minimum space unit so as to better explore the anisotropism and regional differences of city space expansion as well as the impact caused by the adjustment of administrative divisions. With initial analysis, we find that: firstly, on the contrary to the sharp reduction of farming land, the city construction land are for residential communities, factories and mines increases the fastest; secondly, the big central cluster expansion has great regional difference and the three directions of northwest, north and south grows the fastest, which is mainly caused by the positive guidance of trunk roads including highway construction; thirdly, the land area in central cluster used for new construction projects is mainly located in suburban area, but exurb districts of Daxing and Changping also take up a considerable proportion; fourthly, as for the key exurb towns including Changping, Shunyi, and Fangshan, the built-up area also grows rapidly.