Multi-perspective evaluation framework of three-dimensional cooling and energy saving potential of urban parks based on numerical simulation

Abstract

Urban parks can moderate local microclimates and mitigate the urban heat island effect prevalent in cities. Previous research has studied the cooling benefits of parks as well as their potential for energy conservation benefits for local buildings. However, there remains a poor understanding of the nuanced and three-dimensional mechanisms underlying the cooling benefits of urban parks. This study introduces a novel framework of indicators to comprehensively evaluate the three-dimensional cooling properties of parks, encompassing factors such as intensity, volume, and energy saving potential efficiency. The dynamic three-dimensional changes in the cooling effect and energy saving potential of two representative urban parks selected by multisource remote sensing data were simulated during spring, summer and winter days using the ENVI-met microclimate model. The results show that while seasonal variations impact park cooling and energy saving potential, the differences between individual parks outweigh these variations. Factors such as internal vegetation layout, surrounding building morphology, and prevailing wind direction emerge as pivotal factors on the cooling effects, particularly the cooling volume. Notably, the evaluation indicators exhibit distinct patterns of variation between intraday and seasonal analyses, with energy saving efficiency per unit volume demonstrating greatest stability. Furthermore, the exponential growth in the cumulative energy saving potential observed in the larger parks, despite diminishing returns in energy saving efficiency per unit volume. By highlighting the practical importance of evaluating park cooling and energy saving potential from multi-perspective, this study provides new insights into urban park design and management to mitigate urban heat.