Impacts of Small Lakes and Underlying Surface Characteristics on Local Thermal Environments in Summer

In recent years, rapid urbanization in China has significantly altered land use patterns and surface properties, exacerbating the urban heat island (UHI) effect. This study investigates the microclimatic regulation potential of small lakes and their interaction with three distinct underlying surfaces (granite roads, lawns, and woodlands). Hourly measurements of air temperature and relative humidity were conducted from 15 July to 15 August 2024, at Tianlai Lake. The results demonstrate that granite roads exhibited the highest daytime air temperatures due to their low albedo and specific heat capacity. In contrast, lawns and woodlands can reduce surrounding temperatures via latent heat dissipation. The lake’s cooling influence extended approximately 30 m from its boundary, with the air temperature decreasing by up to 2 °C near the shoreline. Relative humidity showed a negative correlation with distance from the lake, declining rapidly within 30 m. These findings highlight the role of small lakes in mitigating UHI effects and provide actionable insights for optimizing lakeside underlying surface planning in urban areas.