基于多源开放数据的城市多中心定量识别方法

Quantitative Identification Method of Urban Multi-center Based on Multi-source Open Data

开展城市多中心研究对于优化城市空间结构、合理配置空间要素及加强城市规划管理具有重要意义。现有研究围绕多中心识别进行了大量实证分析,但尚未建立一套统一的评定标准。为此,本文以POI、人口分布、OSM路网等多源开放数据为基础,构建了一套从结构形态到强度等级和功能分类的城市多中心定量识别方法。(1)结构形态方面,基于对POI数据的多属性加权分析构建多中心结构特征指标—“中心集群度”,并通过参数优化后的局部等值线树算法识别城市多中心的范围与边界。(2)强度等级方面,通过构建多中心综合服务强度指标(UCSI),运用首尾切割规则对多中心内部进行了强度斑块划分并计算多中心强度等级(UCL)。(3)功能分类方面,通过计算融入加权属性后的POI数据的频数占比,识别多中心的功能组合关系与分类。最后以西安市为例进行模拟实证,发现:西安市传统单核心的城市结构表现出明显的扩散趋势,共识别出21个城市中心的位置和边界,分别为3个城市主中心、5个城市副中心以及13个区域中心;各城市中心强度等级呈“核心-外围”圈层式递减特征;识别出4个复合型功能中心、12个双功能中心以及5个单一型功能中心。研究结果表明,本文建立的定量识别方法能够精准、系统地识别城市多中心发展特征。针对大城市多中心发展中的突出问题本文提出了相应的政策建议,以期为城市规划的编制与实施提供借鉴意义。

Conducting research on urban multi-center is of significant importance for optimizing urban spatial structure,rational allocation of spatial elements,and strengthening urban planning and management.Existing studies have conducted numerous empirical research on urban multi-center identification,but a unified set of evaluation criteria has yet to be established.Therefore,based on multi-source open data such as Points of Interest(POI),population distribution,and road networks,this paper constructs a set of quantitative identification methods for urban multi-center in terms of structural morphology,intensity level,and functional classification.For the structural morphology,based on the multi-attribute weighted analysis of POI data,we constructed a multi-center structural characteristic index"center clustering degree"and identified the scope and boundary of urban multi-center through the parameter-optimized local contour tree algorithm.For the intensity level,by constructing the Urban Multi-center Comprehensive Service Intensity Indicator(UCSI),and according to"Head-Tail Breaks"rule,we divided the intensity patches within the multi-center and calculated the Urban Multi-center Intensity Level(UCL).For functional classification,the functional combination relationship and classification of multi-center was identified by calculating the frequency share of POI data after incorporating weighted attributes.Finally,an empirical simulation was conducted using the city of Xi'an as a case study.Results show that Xi'an city's traditional single-core urban structure exhibited a distinct diffusion trend,having a total of 21 urban centers(three main urban centers,five secondary urban centers,and 13 regional centers)with their locations and boundaries specified.The intensity level of each urban center was characterized by a decreasing"core-periphery"circle.And four urban composite functional centers,12 urban dual-functional centers,and five urban single-functional centers were identified.The research results show that the quantitative identification method established in this paper can accurately and systematically identify the characteristics of urban multi-center development.This paper also puts forward corresponding policy suggestions for the prominent problems in the process of multi-center development of large cities and provides reference for the preparation and implementation of urban planning.