Although urbanization has brought about tremendous developments to human society, it has also induced many different problems. In addition, as the total space for city infrastructures and facilities are on a continuous increase, expressed through the ...
Although urbanization has brought about tremendous developments to human society, it has also induced many different problems. In addition, as the total space for city infrastructures and facilities are on a continuous increase, expressed through the urban heat island, accelerating the rate of turning natural land coverings into concrete, having direct affect on the increased level of artificial heat and heat related stress, it has depreciated the quality of life of people living in urban city areas. Heat stress, unlike stress related to cold weather, cannot be biologically controlled by humans, thus being more harmful and dangerous. As stated above, the thermal environment which has direct affect on the behaviors of humans is commonly referred to a "thermal environment," and is expressed in thermal sensation or comfort sensation experienced by humans. Currently, the discomfort index commonly used to describe the level of thermal environment is determined by a simple combination of temperature and humidity, thus making it very difficult to consider the continuation of the most extreme and intimidating weather conditions as well as failing to consider the effects of heat waves during the period of early and late summers where it is difficult to determine the adaptiveness to high temperatures. When we investigated various different studies relating to the urban heat island, we found that majority of the preexisting works have concentrated in understanding the phenomenon by investigating and determining the level of temperature, humidity and other external physical environments. However, it is a widely acknowledged fact that even in conditions where they show identical temperature, different levels of solar radiation and wind speed has significant effect on thermal sensation, and comfort sensation felt by humans. Currently, there are active researches and studies on the thermal comfort satisfaction in indoor environments. However, there is insufficient researches and studies on the thermal comfort satisfaction in outdoor environments. In addition, although research results of sensibility images are widely implicated in various fields including but not limited to urban coordination, city planning, advertisements, and fashion, researches focusing on the implications and affects of sensibility images on humans in outdoor environment is virtually non-existent.
Through various different experiments on human bodies during the summer season, this research focused on measuring thermal sensation, comfort sensation and airflow sensation, as well as trying to index the level of human feelings resulting from the different land cover types. According to different land cover types, we analyzed different atmospheric elements, and tried to evaluate human feelings towards airflow resulting from various different wind velocity. In addition, we determined the domain for the neutral thermal sensation and comfort zone level during rainy days, and studied various different atmospheric elements having direct effect on comfort sensation felt by humans. Using the cause analysis of sensibility image resulting from different land cover types, we tried to simplify and generalize the results as well as representing the sensibility image on a graph using the arithmetic means obtained from the analysis. Finally, through the correlation analysis, we tried to determine the relationship and correlation between thermal sensation, comfort sensation, humidity and airflow.
The results of the research showed that planted area and grassland not only decreased the surrounding temperature but also increased comfort sensation but, paved area and building area not only increased the surrounding environment and also the level of discomfort. In addition, although it is impossible to artificially control the weather in outside environment, unlike those of indoor conditions, when we increase the total mass of grassland, and change the untransmissible packaging of artificial structures to those of transmissible packaging, it is deemed possible to increase the comfort sensation.
From these perspectives listed above, the result of the research has transcended the limitations of previous researches which only concentrated on indoor surroundings by determining thermal comfort in outdoor surroundings according to different land cover types, and has both academic and practical value in improving the outdoor thermal environments in the future.