Exploring the adaptive spatial patterns and impact factors for the cooling effect of park green spaces in riverfront area

The park green spaces (PGSs) distributed in riverfront area have blue-green synergistic cooling effect, and their cooling efficiency is influenced by their spatial morphology. Five typical spatial patterns of PGSs were selected, and the correlation between morphology indices of the internal plant landscape space (PLS) and the cooling effect distribution was analyzed based on ENVI-met simulation and Boosted Regression Tree models. The results showed the optimal cooling effect of PGSs in riverfront area is achieved in the type of multi-center pattern and patch scattered pattern, which all have the moderate combination of PLS's open space and dense vegetation spaces. And the spatial factors of distance from the riverbank, green biomass, and canopy density, with respectively higher contribution ratios of 47.65%, 9.49%, and 8.29% to the cooling effect, have greater impacts on riverfront thermal environment. Furthermore, through the spatial heterogeneity study of cooling characteristics based on partitioned functional zones (namely, the riparian zone, the vegetation zone, the recreation zone, and the entrance zone), specific cooling adaptive optimal paths and strategies for each functional zone under different types of green space patterns is proposed. The study provides a set of reasonable planning methods and optimization criteria for enhancing urban cooling island.