How do landscape patterns affect cooling intensity and scale? Evidence from 13 primary urban wetlands in China

Urban wetlands are important blue-green spaces in cities and, hence, play a pivotal role in regulating local urban ecological environments and thermal conditions. However, despite their significance, studies on the cooling effects of urban wetlands, as well as the influencing factors, remain limited. This study used multi-ring buffer analysis and random forest (RF) model to calculate the significant and potential cooling scales and intensities in urban wetlands. More specifically, we introduced four indicators, integrated patch diversity and proximity (IPDP), integrated wetland proximity and shape (IWPS), patch aggregation (PA), and logarithmic area (LA), to enhance urban wetland characteristic representation, and conducted correlation analyses to investigate their relationships with the cooling effects. The results revealed significant cooling scale and cooling intensity ranges across the 13 urban wetlands. Similarly, potential cooling scales varied from 10,284 to 44,408 m, with potential cooling intensities ranging from 0.35 to 1.81 degree celsius. Notably, factors such as IWPS, number of patches (NP), and PA significantly influenced the cooling effects, whereas LA emerged as a key factor affecting potential cooling effects. This study highlights the importance of urban wetlands in reducing urban thermal conditions, and advances the understanding of their cooling effects.