Effects of district parameters, green space and building density on thermal comfort- a case study of Badaguan District in Qingdao

It is challenging for most Historical Preservation Areas (HPA) to improve thermal comfort, especially under the contradiction of urban preservation. The study selected the Badaguan Dis-trict as the object, which is the most famous HPA in Qingdao. Simulation is conducted by ENVI-met based on field measurements. Taking the current situation (green space 46.6% and building density 17.8%) as the basic case, we modeled two cases (reducing the green space to 29.1% and increasing the building density to 29.9% respectively according to the local standard). The results show that: (1) There are significant differences in air temperature and relative humidity among different streets; (2) District parameters including sky view factor (SVF) and Aspect Ratio(H/W) have different impact on microclimate; (3) Reducing the percentage of the green space(GS) to 29.1% (Case I)and increasing the percentage of the building density(BD) to 29.9% (Case II) both make the microclimate deteriorate. (4) By comparing the thermal comfort calendars of three cases, the thermal environment of the basic case is the best, and thermal environment of Case II is the worst especially at 12:00. The study can inform policy makers and urban designers to discover the balance between preservation of HPA and thermal environment improvement.