With further improvements to meet social requirements for healthy and comfortable living, the research of micro-scale thermal environments has been received increasing attention. The key to micro-scale thermal environment study is the underlying surface temperature field simulation, which requires high precision results. Taking a typical area of the Jiangning District, Nanjing City, as a study area, this study used a UAV equipped with a thermal infrared imager to obtain surface temperature data in summer and autumn because of the limitation of the traditional ground measurements. Then, the numerical simulation software of ENVI-met and PALM-4U were utilized to conduct the surface temperature filed simulation. The simulation results were further analyzed combined with measured data. The modeling results indicated that the numerical simulation has high spatial accuracy, which can be applied to the study of the urban micro-thermal environment. Furthermore, the simulation effect of the model on the artificial surface is better than that of the natural surface, and the simulation effect of the open surface is better than that of the non-open surface. The study also found that the simulation effect of ENVI-met under the influence of occlusion was better than that of PALM-4U. The vegetation occlusion PALM-4U was less effective than that of ENVI-met, although both models correctly predicted the ground temperature under the occlusion of buildings. The overall conclusion indicates that the applicability of ENVI-met is superior to that of PLAM-4U for urban micro-thermal environment simulation. The study can provide a reference for the high-resolution remote sensing research of urban micro-scale thermal environments.
Keywords: ENVI-met; PALM-4U; UAV thermal infrared data; numerical simulation verification; urban micro-thermal environment; urban surface temperature field.