Study on water cooling island effects under different climatic conditions

Water bodies are regarded as effective tools to improve urban thermal environment. However, there is little information regarding the impacts of the water bodies under different climatic conditions. In this study, the thermal effects of similar water bodies were investigated in a temperate monsoon climate city (Xi’an) and a humid subtropical climate city (Chengdu) in summer. Results showed that both the water bodies reduced the air temperature and increase the humidity in their vicinity, and the closer to the water body the more obvious the effects. However, the water body in Xi’an could provide cooling to its surroundings all day, while the one in Chengdu had warming effect at night. In this study, the universal thermal climate index (UTCI) around the water bodies was also investigated. It was found that both water bodies would improve the thermal comfort in their vicinity, and the thermal comfort achieved by the cooling effect was not cancelled out by the humidity change. In addition, it was found that the actual thermal sensation of the human body can be different for same UTCI values in Xi’an and Chengdu, which indicated the necessity to modify the thermal benchmarks before investigating the thermal comfort in different cities.