基于建筑物空间特征的北京市城市空间结构及其机制分析

Study on the spatial structure and driving force of urban areas in Beijing based on building space structure

定量研究城市空间结构特征是城市地理学研究的核心内容。基于建筑物空间结构特征的分析,研究北京市城市结构特征及变化规律。根据建筑物空间结构的特点设计了一种城市结构的"向量"模型,利用行政区划、同心圆区划和扇形区划三种不同分区数据分别分析北京城市建设中心、城市建设方向和城市建设强度。结果表明,本文的方法能够很好的刻画出北京市城市结构的空间形态及其变化规律:①北京市城市建设由于城市功能扩散及积聚作用的影响呈现内城向外城扩张建设、外城向内城积聚建设的单方向推进发展特征;②由于重大事件的影响,单方向推进会变化方向发生调头发展或者多次迂回发展,形成北京市城市结构的多重形态;③北京城市蔓延区的产生原因不仅仅是城市功能的扩张,也是由于外延区县城市功能向城市中心集聚造成的;④北京城市空中扩展是伴随着城市平面扩张同时进行的,并且其空中扩展的地带也在向城市外延发展;⑤北京的"双轴"结构已经确立,然而"东西轴"比"南北轴"要更为成熟。同时,北京市城市发展在方向上的差异正在减弱,呈现均衡的发展态势。

Quantitative study of urban spatial structure is the core content of urban geography research. Based on analysis of the building space structure, we explored urban spatial structure and its change rules. According to the characteristics of the building space structure, we designed a ＂vector model＂ to explore urban spatial structure. In this model, we applied three different polygon-based data, administrative districts, concentric circles and fan divisions, to respectively analyze urban construction center, urban construction direction and intensity of urban construction. The results show that this method well characterizes the change rules of Beijing urban spatial struc^tre. The characteristics and rules reveal that： （1） Beijing city develops in a single direction because of the effects of urban function diffusion and agglomeration. The inner city expands to the outer city, and the outer city agglomerates to the inner city; （2） Due to the influence of the major events, urban area may expand to the opposite direction or form a bidirectional development; （3） The reason of urban sprawl in Beijing is not only the expansion of inner city, but also the agglomeration of outer city; （4） The urban area of Beijing city develops towards the air while sprawling, and the new denser urban regions tend to occur in the urban fringe; （5） ＂Biaxial structure＂ of Beijing urban area has been established, but ＂west-east axis＂ is more notable than ＂north-south axis＂. Now, the differentiation of Beijing urban development in each direction is decreasing, and Beijing has a balanced development in each direction.