辽宁沿海城市带是中国环渤海地区的重要组成部分。在辽宁沿海经济带开发上升为国家战略的背景下,该区域城市群空间结构必然面临着转化与重组。本文以辽宁沿海城市带24个大、中、小城市为空间单元,分别从城市规模、经济发展水平、交通网络通达性3方面讨论城市群集聚程度,并对其空间分布特征进行分析,结果表明:①城市规模等级差异明显,首位城市垄断性强。通过构建规模指数模型,将该区域24个规模不等的城市分为4级,同级城市规模指数幅度变化不大,但是不同级别城市之间规模差异很明显。进一步运用首位度、分形理论等方法分析城市规模分布的空间特征,发现该区域城市首位分布明显,城镇规模分布较为松散,人口空间分布差异程度较大。②经济发展格局具有明显的层序性,空间集聚现象显著。经济空间结构呈现非均衡分布状态,而且各城市的经济发展水平之间存在较强的空间正相关关系,具有相似发展水平的城市在空间上具有显著的集聚及两极分化现象,发展水平较高的城市集中布局于辽东半岛,而辽宁省西部以及东南部的经济极化现象较弱。③通达性空间分异明显,交通网络仍有很大发展潜力。通达性最优区域集中分布在该区域的几何中心以及辽东半岛地区,辽西、辽东南的通达性值普遍较高。④综合以上分析,发现辽宁沿海城市带空间结构为典型的条形核心—外围—边缘结构,具有大连、锦州、营口3个强中心,其中大连的极化作用最强。
Urban agglomeration in Liaoning coastal area which lies around the Bohai Bay is the only access to the sea in Northeast China.Since 2009,the region has been the focal point in national strategy,so the spatial structure is facing transformation and restructuring.In this paper,we analyze the spatial structure characteristics of the urban agglomeration from the following three aspects: the urban scale ranking,economic development level and the spatial accessibility.All of the cites in this region are ranked by the calculated results of index mod-els and mathematical approaches correspondingly.The authors also discuss the spatial structural characteristics by using the relative analysis,fractal theory and ESDA(Exploratory Spatial Data Analysis) and topology analy-sis.It is concluded that:(1) the differences in scale ranking are evident,and the urban system is distributed with high urban primacy ratio;(2) the differences for economic development are also great,and the phenomenon of spatial agglomeration of cities with equal economic level is distinct;(3) the spatial variation of accessibility is obvious,and the transport network still has much potential for development;(4) on the basis of the above analy-ses,it is concluded that the spatial structure of urban agglomeration in Liaoning coastal area shows a core-pe-riphery-edge pattern.There are three strong core cities,Dalian,Jinzhou and Yingkou,and DaLian is the most centralized city.