Green infrastructure network construction method for mitigating urban heat island effect in Nanjing

Abstract

Objective  As an ecological network covering the city, green infrastructure (GI) network plays an important role in mitigating the heat island effect. The purpose of this study is to explore the construction method and reasonable planning and layout of GI, as well as effective measures to improve the urban thermal environment. Method  The main urban area of Nanjing City in Jiangsu Province was taken as the research object. Based on the morphological spatial pattern analysis (MSPA), the “source” patches with high connectivity and significant cooling effect were selected. The landscape pattern index reflecting the landscape pattern and the surface cooling rate reflecting the surface coverage characteristics were superposed to construct the resistance surface. Then, the minimum cost path method was used to generate corridors. Result  1) 507 core patches with high cooling rate were identified, and 25 patches were selected as “source” patches based on landscape connectivity analysis. 2) 20 corridors were identified by the minimum cost path method. Together with the “source” patches, the urban GI network was constructed to mitigate the heat island effect. 3) The network was optimized based on Green Space System Planning of Nanjing, and the overall spatial structure of “three rings, six belts and multiple lines” was proposed. Conclusion  The comprehensive application of various methods makes it more reasonable to construct a GI network to mitigate the heat island effect, and provides a new research approach for building a GI network and improving urban living environment.[Ch, 5 fig. 6 tab. 27 ref.]