Simulation Analysis of the Cooling Effect of Urban Water Bodies on the Local Thermal Environment

Abstract

Urban water bodies have a cooling effect and alter the local urban thermal environment. However, current research is unclear regarding the relationships between factors such as the spatial density, area proportion, and distribution pattern of water bodies and the cooling effect of water on the local thermal environment. To clarify these relationships, it is critical to quantify and evaluate the influence these factors have on the cooling effect of water in the urban landscape. Therefore, we analyzed the cooling effect of different water bodies on the local thermal environment at the microscale by comparing their area proportions and distribution patterns using numerical simulations. Furthermore, we analyzed the day–night variation in the cooling effect of urban water bodies with different areas and distribution patterns. We used the area proportion, separation index (SI), and landscape shape index (LSI) to indicate the layouts of water bodies. The results showed that the cooling effect of a water body was higher during the day than at night. These results also showed that area proportion and LSI were positively correlated with the water body’s cooling effect. However, the efficiency of the cooling effect gradually decreased with increasing area proportion. When the LSI increased, more areas within the region displayed larger cooling effect values, but the uniformity of the regional cooling diminished. Additional results showed that the cooling effect had no significant positive correlation with SI. A moderate SI could enhance the uniformity of the cooling effect in the region and link the cooling effect between water patches.