南沙新区城市生态网络构建与连通胁迫分析

Construction and Connectivity Stress Analysis of Urban Ecological Network in the Nansha New District

优化生态网络结构与增强生境连通性是保障城市生态安全的关键,结合城市大数据能更精确地揭示人类活动的空间异质性对生态连通的胁迫效应。现有研究受限于矫正阻力数据精度与源地廊道识别方法的不足而难以建立带属性的生态网络,因而对中小尺度城市生态网络构建与连通胁迫分析较为匮乏。文章基于POI数据与土地利用数据构建综合阻力面,利用InVEST模型与电路理论构建具有量化属性的生态网络,并明晰网络中影响廊道连通的胁迫因子与干扰强度。结果表明:1)南沙新区整体生境质量处于良好水平,生态源地中心性介于26.8~69.26,源地中心性与源地面积加权重心距离成反相关;多数生态廊道连通性为17.56~92.56,廊道连通性与廊道长度、阻力具有反比关系。2)南沙新区生态网络由18个高生境质量源地、40条最优生态廊道以及125.70km²的潜在廊道所组成,在空间上呈现“中部密、南北疏”的内敛格局,中部廊道分布较为密集、长度较短、连通性较高且源地分布集中,而南北两端则零散分布着低级源地且形成较多长距离、低连通性的廊道。3)胁迫生态廊道连通的POI设施由强到弱依次为公司企业、交通设施、生活服务与购物消费,削减与控制以上4类POI在潜廊道范围内的数量,将有效增强生态网络连通性并缓解源地孤岛化、生境碎片化趋势。

Optimizing the ecological network structure and enhancing habitat connectivity are key to ensuring urban ecological security,and the combination of urban big data can more accurately reveal the stress effects of the spatial heterogeneity of human activities on ecological connectivity.In recent years,numerous studies have focused on urban ecological networks;however,they have been limited by the accuracy of correction resistance data and the lack of source corridor identification methods,which makes it challenging to establish ecological networks with attributes.Thus,small-and medium-sized urban ecological network construction and connectivity stress analysis are lacking.In this study,a comprehensive resistance surface was constructed based on Point of Interest(POI)data and land use data;an ecological network with quantitative attributes was constructed using the InVEST habitat quality analysis and circuit theory,and the stress factors and disturbance intensity affecting the corridor connectivity of the network were clarified.Three main conclusions were drawn from the above analysis.First,the overall habitat quality of Nansha New District is good,and the centrality of ecological source areas ranges from 26.8 to 69.26.This centrality is inversely correlated with the source area's weighted center of gravity distance and positively correlated with the source area.The connectivity of most ecological corridors is between 17.56 and 92.56 and is inversely proportional to the corridors'length and resistance.Second,the ecological network of Nansha New District consists of 18 high habitat quality sources,40 optimal ecological corridors,and 125.70 km²of potential corridors,spatially showing an introverted spatial pattern of"dense in the middle and sparse in the north and south."The corridors in the middle are more densely distributed and shorter in length and have higher connectivity and a concentrated distribution of sources.The north and south ends are scattered with low-level sources and the formation of more long-distance corridors with low connectivity.Finally,the main threatening factors of corridor connectivity in Nansha New District are four types of POI facilities,namely,companies,transportation facilities,shopping consumption,and life services.The numbers of corridors mainly coerced by companies,transportation facilities,life services,and shopping consumption POI are 23,10,5,and 2,respectively.Reducing and controlling the number of the above four types of POIs in the latent corridors will effectively enhance the connectivity of ecological networks and alleviate the isolation of source areas,reducing the trend of source islanding and habitat fragmentation.The research results can provide a concrete entry point for the maintenance of an excellent ecological background in Nansha New District in terms of spatial scope and facility renovation,which is of practical significance for the construction of a high-quality urban development benchmark.