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

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 km² of 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