Study On Beijing Spatial Structure And The Comparison With The World Cities

At present,Beijing's urban diseases such as population congestion and industrial highly agglomeration have become increasingly serious.Many scholars study Beijing's spatial structure as a whole object at a macroscopic scale,compare the differences of urban spatial structure with the three world cities—London,New York and Tokyo,and analyze the reason for Beijing's urban diseases.However,the research about the inner spatial structures of Beijing is not enough.This paper aims to study the inner spatial structures of population and industries within the built-up areas of Beijing and analyze the differences of spatial structures between Beijing and the three world cities based on the available data.We put forward the pertinent suggestion for evacuating the resident people,optimizing the industrial layout,properly configuring the elements on the land surface,and controlling Beijing's urban diseases.First,a novel method to extract urban built-up area is proposed based on the spatial scale effect.This method obtains the different thresholds by gradually reducing the spatial scales.We apply the method to extract the built-up areas of Beijing and the three world cities using GF-2 remote-sensing data.Second,we analyze the resident population distribution of street units in Beijing built-up areas and construct the relational model between resident population and building volume to simulate the resident population distribution at 100-m spatial scale.We utilize the index of point density to produce point density map of resident population and analyze the spatial distribution pattern of the resident population in Beijing built-up area.Third,we use the point of interest extracted from electronic maps to simulate the industries distribution and analyze the spatial distribution for some major industries.Fourth,we use the deviation index to measure the separation between resident population and industries by integrating the point densities of resident population and industries.Fifth,we simulate the resident population distribution for the three world cities at 100-m scales using the census data and compare the differences of the spatial structure between Beijing and the three world cities.Based on the land cover data,we use landscape indexes to compare the difference of land cover structure between Beijing and the three world cities.The main conclusions are as follows:(1)The spatial structure of resident population distribution appears an ‘M' shape in Beijing.Many resident population centralizes in the layer away from city central of 1km to 3km,5km to 10 km,where the population are 3,141,000,5,321,000 respectively.The resident population in the range of 10 km is 10,773,000,which is more than 80%.The resident population densities are imbalanced with large difference.The resident population density in some areas outside of the 4th ring road is lower than 5000 per square kilometer while the inside is higher than 25,000 per square kilometer.The spatial structure of resident population distribution appears an inverted ‘U' shape in Tokyo and London.The resident population distribute in Beijing more evenly than in Tokyo and London.(2)The industries in Beijing built-up area are concentrated in the inner part of the 4th ring road.The general manufacturing industries concentrate in the district of Zhongguancun,Guomao.Food service industries concentrate in the district of Chaoyangmen and Zhongguancun.Shopping service industries form the high density area from the Forbidden City eastward to the Guomao.Consumer,transportation,financial services concentrate in the east and the west sides of the Tiananmen.Education and culture services concentrate in the district of Zhongguancun.Medical insurance services concentrate around the Forbidden City.The leisure sports services concentrate in the district of Sanlitun.(3)The spatial deviation between the resident population and the industries is higher in Huilongguan town,Shahe area,Beiqijia town,Dongxiaokou town,Huangcun town,Heizhuanghu town,Taihu town,Yizhuang town,and Beizang town.(4)Compared with the three world cities,the area ratio of water bodies is little and the water bodies are unevenly distributed;green space are excessively focus on the large parks and their fragmentation is lower;the connectivity of road network is lower and the network appears ‘grids+ring' structures in Beijing.(5)We suggest evacuating the resident population in the range of 3km to 8km,guiding major medical institutions to Tongzhou district,guiding education and culture services to Changping,Daxing and Fengtai district,guiding manufacture industries to the suburbs of Changping,Daxing,and Fengtai district,and complete the supports for the life services in Tongzhou,Changping,and Daxing district.