Evaluation of a microclimate model for predicting the thermal behavior of different ground surfaces

The microclimate model ENVI-met Version 4 was evaluated with field data in terms of the thermal behavior of different types of ground surface. A field experiment was conducted in a real construction project in Guangzhou, South China, from 29 August to 2 September in 2010. The surface types of concrete, tile, asphalt and grass were investigated. The comparison between observation and prediction was performed for both sub- and above-surface variables, including soil temperature at different depths, soil heat flux at the surface, surface temperature, and air temperature and humidity at different heights. The results show that the ENVI-met model is capable of reasonably modelling the diurnal thermal behavior of different ground surfaces and their effects on local air temperature and humidity. The comparison of spatial distributions of air temperature and humidity shows that the hotter/drier and cooler/wetter spots predicted by ENVI-met were generally consistent with the observations. The quantitative evaluation shows that the ENVI-met model is capable of predicting the microclimate in terms of different variables with good accuracy.