广州市绿道网络连通性、可达性及其对城市化的响应

The connectivity and accessibility of Guangzhou greenway network and their response to urbanization

采用密度分析法、网络结构指数法、形态学空间格局分析法以及网络分析法等对广州市绿道的分布特征、连通性和可达性进行量化研究,对可能影响广州绿道建设的社会经济因素进行相关性检验。结果显示,广州市平均绿道密度为0.44 km·km^(-2),人均绿道长度为0.21 m,绿道建设以老城四区(越秀、荔湾、海珠、天河)为集聚中心,以圈层形式逐渐向外减弱;绿道网络结构指数α、β和γ分别为0.149、1.297和0.65,网络闭合度相对较低,但网络复杂度较高且连接度良好,与广州市内95.82%生态源地相连通;越秀区、海珠区、荔湾区、天河区绿道网可达性优良,白云区、黄埔区、番禺区和增城区绿道网可达性一般,南沙区、花都区、从化区绿道网可达性较差;城镇化率、人口密度和路网密度对广州市绿道建设具有显著正向影响,R^(2)值分别为0.749、0.634和0.715。广州市绿道在老城四区分布密集、网络结构较为完善、可达性优良,各项指标存在向外逐渐递减趋势。为促进广州市早日形成完善的可持续生态空间网络,要加强外围城区绿道建设,着力改善网络结构,以良好的结构带动绿道功能充分发挥,最终实现广州绿道人人共享。

The distribution characteristics, connectivity, and accessibility of Guangzhou greenway were quantified by density analysis method, network structure index method, morphological space pattern analysis method, and network analysis method. Furthermore, correlation analyses between greenway density and four socioeconomic indicators(i.e., economic development level, road network density, urbanization rate, and population density) were carried out to detect key factors influencing the construction of Guangzhou greenway. The results showed that the average greenway density in Guangzhou was 0.44 km·km, and the per capita greenway length was 0.21 m. The construction center of greenway was located in “the-Four-Old-Districts”(Yuexiu, Liwan, Haizhu, Tianhe) and gradually weakened outward in the form of circles. The greenway network structure indices α, β, and γ was 0.149, 1.297, and 0.65, respectively. The network closure degree was relatively low but the complexity and the connectivity were high. 95.82% of the ecological source patches were connected in Guangzhou. The districts with excellent accessibility included the greenway network in Yuexiu, Haizhu, Liwan, Tianhe. The districts with normal accessibility included the greenway network in Baiyun, Huangpu, Panyu, Zengcheng. The districts with relatively poor accessibility included the greenway network in Nansha, Huadu, Conghua. Urbanization rate, population density, and road network density had a positive impact on the greenway construction in Guangzhou, with the value of R~2 being 0.749, 0.634, and 0.715, respectively. Guangzhou greenways were densely distributed in “the-Four-Old-Districts”, where the network structure was relatively complete and the accessibility was generally convenient, and there was a downward trend for various indicators. To comprehensively promote the formation of a sustainable and ecological space network in Guangzhou as soon as possible, more efforts are needed to construct high-quality greenways on peripheral urban areas, optimizing the spatial structure, improving ecosystem functions, and realizing the goal of shared greenways by all citizens.