본 연구는 중국 산둥성 쯔보시의 도시공원 중 하루 평균 인구 유동량이 가장 많은 인민공원, 횃불공원, 치성호공원을 대상으로 식재경관 조성에 중요한 영향을 미치는 20개 식재경관 지표를 선정한 후 공원 이용자들이 식재경관에 중요도와 이용 후 만족도에 관한 설문조사를 실시하였다. 수집된 자료는 IPA 분석을 활용하여 식재경관 지표별 중요도 및 만족도를 파악하고 개선이 필요한 지표를 도출하였다. 연구결과, 중요도 분석에서는 인민공원과 치성호공원은 식물종 다양성, 횃불공원은 나무의 그늘이 가장 중요한 지표로 분석되었다. 한편, 만족도 분석에서는 인민공원 및 횃불공원은 나무의 그늘, 치성호공원은 식물종 다양성이 가장 높은 만족도를 가지는 것으로 나타났다. 대응표본 T-검사 결과, 인민공원은 16개 지표, 횃불공원은 15개 지표, 치성호공원은 15개 지표가 중요도 및 만족도 사이에 뚜렷한 통계적 차이가 있는 것으로 분석되었다. IPA 분석결과, 인민공원은 사계절 경관 등 4개 지표, 횃불공원은 꽃모양의 다양성 등 4개 지표, 치성호공원은 식물 층위의 미 등 3개 지표가 중요도는 높았으나 만족도가 낮게 나타나 중점적으로 개선해야 한 지표로 도출되었으며, 이를 토대로 중점적으로 개선해야 한 지표에 대해 개선방안을 제안하였다. 연구를 통하여 공원 이용자들의 식재경관 만족도를 향상하고 더 좋은 식재경관 체험을 할 수 있을 것으로 기대된다.

Recently, summer high temperature events caused by climate change and urban heat island phenomenon have become a serious social problem around the world. Urban areas have low albedo and huge heat storage, resulting in higher temperatures and longer lasting characteristics. To effectively consider the urban heat island measures, it is important to quantitatively grasp the impact of urban high temperatures on the society. Until now, the study of urban heat island phenomenon had been carried out focusing only on the effects of urban high temperature on human health (such as heat stroke and sleep disturbance). In this study, we focus on the effect of urban heat island phenomenon on air pollution. In particular, the relationship between high temperature phenomena in urban areas during summer and the concentration of photochemical oxidant is investigated. High concentrations of ozone during summer are confirmed to coincide with a day when the causative substances (NO2,VOCs) are high in urban areas during the early morning hours. Further, it is noted that the night urban heat island intensity is large.. Finally, although the concentration of other air pollutants has been decreasing in the long term, the concentration of photochemical oxidant gradually increases in Daegu.

In order to investigate the effect of air temperature reduction on an urban neighborhood park, air temperature data from five inside locations (forest, pine tree, lawn, brick and pergola) depending on surface types and three outside locations (Suwon, Maetan and Kwonsun) depending on urban forms were collected during the summer 2016 and compared. The forest location had the lowest mean air temperature amongst all locations sampled, though the mean difference between this and the other four locations in the park was relatively small (0.2-0.5℃). In the daytime, the greatest mean difference between the forest location and the two locations exposed to direct beam solar radiation (brick and lawn) was 0.5-0.8℃ (Max. 1.6-2.1℃). In the nighttime, the mean difference between the forest location and the other four locations in the park was small, though differences between the forest location and locations with grass cover (pine tree and lawn) reached a maximum of 0.9-1.7℃. Comparing air temperature between sunny and shaded locations, the shaded locations showed a maximum of 1.5℃ lower temperature in the daytime and 0.7℃ higher in the nighttime. Comparing the air temperature of the forest location with those of the residential (Kwonsun) and apartment (Maetan) locations, the mean air temperature difference was 0.8-1.0℃, higher than those measured between the forest location and the other park locations. The temperatures measured in the forest location were mean 0.9-1.3℃ (Max. 2.0-3.9℃) lower in the daytime than for the residential and apartment locations and mean 0.4-1.0℃ (Max. 1.3-3.1℃) lower in the nighttime. During the hottest period of each month, the difference was greater than the mean monthly differences, with temperatures in the residential and apartment locations mean 1.0-1.6℃ higher than those measured in the forest location. The effect of air temperature reduction on sampling locations within the park and a relatively high thermal environment on the urban sampling locations was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with a high sky view factor and surface types with high evapotranspiration potential (e.g. grass) showed the maximum air temperature reduction. In the urban areas outside the park, the low-rise building area, with a high sky view factor, showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, while in the nighttime the area with high-rise buildings, and hence a low sky view factor, showed high air temperature due to the effect of terrestrial (longwave) radiation emitted by surrounding high-rise building surfaces. The effect of air temperature reduction on the park with a high thermal environment in the city was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with high sky view factor and surface types (e.g., grass) with evapotranspiration effect showed maximum air temperature reduction. In the urban areas outside the park, the high sky view factor area (low-rise building area) showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, but in the nighttime the low sky view factor area (high-rise building area) showed high air temperature due to the effect of terrestrial (longwave) radiation emitted surrounding high-rise building surfaces.

We analyzed diurnal variations in the surface air temperature using the high density urban climate observation network of Daegu in summer, 2013. We compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas are faster than in urban areas. It is mainly due to the difference of surface heat capacity. In addition, local wind circulation also affects the discrepancy of thermal spatiotemporal distribution in Daegu. Namely, the valley and mountain breezes affect diurnal variation of horizontal distribution of air temperature. During daytimes, the air(valley breeze) flows up from urban located at lowlands to higher altitudes of rural areas. The temperature of valley breeze rises gradually as it flows from lowland to upland. Hence the difference of air temperature decreases between urban and rural areas. At nighttime, the mountains cool more rapidly than do low-lying areas, so the air(mountain breeze) becomes denser and sinks toward the valleys(lowlands). As the result, the air temperature becomes lower in rural areas than in urban areas.

This study measured temperatures and albedos of urban surfaces for different colors and materials during summer, and calculated the energy budget over different urban surfaces to find out the thermal performance affecting the heat built-up. The study selected six surface colors and 13 materials common in urban landscape. Their surface temperatures (Ts) and albedos were measured at a given time interval in the daytime from June to August. Average Ts over summer season for asphalt-colored brick was 4.0℃ higher than that for light red-colored one and 9.7℃ higher than that for white-colored one. The Ts for artificial surface materials of asphalt paving, brown brick wall, and green concrete wall was 6.0℃ higher than that for natural and semi-natural ones of grass, grassy block, and planted concrete wall. There was the greatest difference of 16.3℃ at midafternoon in the Ts between asphalt paving and planted concrete wall. Average albedo over summer season of surface materials ranged from 0.08 for asphalt paving to 0.67 for white concrete wall. This difference in the albedo was associated with a maximum of 15.7℃ difference at midafternoon in the Ts. Increasing the albedo by 0.1 (from 0.22 to 0.32) reduced the Ts by about 1.3℃. Average storage heat at midday by natural and semi-natural surfaces of grass and grassy block was about 10% lower than that by artificial ones of asphalt, light-red brick, and concrete. Reflected radiation, which ultimately contributes to heating the urban atmosphere, was 3.7 times greater for light-red brick and concrete surfaces than for asphalt surface. Thus, surfaces with in-between tone and color are more effective than dark- or white-colored ones, and natural or semi-natural surfaces are much greater than artificial ones in improving the urban thermal environment. This study provides new information on correlation between Ts and air temperature, relationship between albedo and Ts, and the energy budget.

We analyzed diurnal variations in the surface air temperature using the high density urban climate observation network in Daegu metropolitan city, the representative basin-type city in Korea, in summer, 2013. We used a total of 28 air temperature observation points data(16 thermometers and 12 AWSs). From the distribution of monthly average air temperature, air temperature at the center of Daegu was higher than the suburbs. Also, the days of daily minimum air temperature more than or equal to 25℃ and daily maximum air temperature more than or equal to 35℃ at the schools near the center of Daegu was more than those at other schools. This tendency appeared more clearly on the days of daily minimum air temperature more than or equal to 25℃. Also, the air temperature near the center of the city was higher than that of the suburbs in the early morning. Thus it was indicated that the air temperature was hard to decrease as the bottom of the basin. From these results, the influence of urbanization to the formation of the daily minimum temperature in Daegu was indicated.