The effects of the cooling efficiency of urban wetlands in an inland megacity: A case study of Chengdu, Southwest China

摘要

Although considered an effective means to alleviate the urban heat island effect, the cold island effect of urban wetlands and its influencing factors remain unclear, especially in inland basin areas. Chengdu, a typical inland metropolis in Southwest China, was chosen as the case study area to study the cooling effect of wetlands and the impact of the spatial form of wetlands (e.g., size, shape, hydrological connectivity) on the cooling effect, and optimized strategies for the cooling efficiency of urban wetlands were proposed. The results showed that (1) the cooling intensity logarithmically increased with the wetland size and that the threshold value of efficiency (TVoE) was 1.47 +/- 0.34 ha. (2) The hydrological connectivity significantly influenced the cooling effect, accounting for 28.2% of the total. (3) The wetlands within the high-density building areas had a relatively high cooling efficiency, while the green space could expand the cooling extent. We propose building a number of small and connected wetlands in densely built-up areas instead of building large and isolated wetlands to improve the cooling efficiency of urban wetlands.