Development and Preliminary Validation of Integrated Local Microclimate Model for Numerical Evaluation of Cool Pavement Strategies

Abstract

Cool pavement strategies can help mitigate the heat island effect and improve the outdoor thermal environment in hot climates. This study developed a framework for a general integrated local microclimate model that included the pavement structure and near-surface air and considers coupled processes of radiation, convection, conduction, shading, and evaporation. A simplified numerical model based on heat transfer was developed to simulate the thermal behavior of pavements with a focus on the pavement surface. The model was used to simulate the temporal and spatial distribution and variation of pavement temperature during the summer in a hot region (Sacramento, California). Preliminary validation of the model was accomplished with field measurements from experimental test sections on asphalt and concrete pavements (of various materials and structures) and under various weather conditions during summer. The simulated results agreed well with the measurements recorded on the test pavements, but further validation will be required before the use on any pavement under any climatic condition can be considered. The results indicated that the model could be used after further validation to simulate temperature changes on asphalt and concrete pavement surfaces under various climatic conditions. The model could also be used for simulation-based sensitivity analysis of key factors when identifying potential effective strategies for cool pavements, evaluating the thermal behavior of cool pavement strategies, and examining the impacts of cool pavements on near-surface heat island effects (such as human thermal comfort and air quality issues associated with ground-level ozone) over time and climates.