Numerical investigation of thermal-humidity environment in pedestrian area of ecological community with the porous pavement in arid areas

In this paper, the water evaporation from porous pavement is used to improve the thermal-humidity environment (THE) in pedestrian area of ecological community at the large wind and sand, and arid areas, such as Lanzhou in northwest China. A simulation model is established to analyze the THE of ecological community with the porous pavement in arid areas. And the water evaporation is considered from plant transpiration and porous pavement in this model. The simulation results are compared with the experimental results, the relative error was less than 13.5%. At the same time, the THE is also analyzed under different building layout, building spacing and building height. The results show that the average value of universal thermal climate index (UTCI) in pedestrian area increases with the building height, while the minimum value has little difference. This means that the local thermal discomfort would more likely occurs in ecological community with the building height increase. The local value of UTCI in pedestrian area decreases by about 8℃ when the building spacing is changed from 10 m to 40 m. The uniformity of UTCI is greatly improved when the building spacing rises to 25 m. The array building layout should be adopted in Lanzhou, the building spacing should be at least 25 m when the building height is 50 m. The above research results can provide theoretical guidance for improving the thermal comfort level of ecological community in Lanzhou.