Does the restoration of an inner-city stream in Seoul affect local thermal environment?

• Published in: Theoretical and applied climatology Vol. 92; no. 3-4; pp. 239 - 248
• Main Authors: Kim, Y.-H., Ryoo, S.-B., Baik, J.-J., Park, I.-S., Koo, H.-J., Nam, J.-C.
• Format: Journal Article
• Language: English
• Published: Vienna Springer-Verlag 01.05.2008; Springer; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Climate; Climatology; Climatology. Bioclimatology. Climate change; Creeks & streams; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Temperature; Waste Water Technology; Water Management; Water Pollution Control; Far East; Asia; Korea; Cheonggyecheon South Korea; Seoul South Korea; Korea, Rep., Seoul; Urban Heat Island; Urban Heat Island Intensity; Stream Effect; Automatic Weather Station; Planetary Boundary Layer Height; Thermal comfort; heat balance; Radiation balance; streams; Summer; Impact study; urban areas; urban planning; Microclimate; Bioclimatology; Atmospheric temperature; Micrometeorology; Atmospheric boundary layer; Effect on climate
• ISSN: 0177-798X; 1434-4483
• DOI: 10.1007/s00704-007-0319-z

Summary Changes in local thermal environment associated with the restoration of an inner-city stream in Seoul, Korea, are investigated using observational data. The stream, called the Cheonggye stream, which had been hidden and covered with cement/asphalt for 46 years, runs 5.8 km eastward through a central region of Seoul. Intensive observations were made in the stream area for a number of summertime periods before, during, and after the stream restoration to detect the effects of the stream on local environment and to quantify them. It is estimated that after the stream restoration the near-surface temperature averaged over the stream area dropped by 0.4 °C, with the largest local temperature drop being 0.9 °C. However, it cannot be stated that this 0.4 °C temperature drop is due entirely to the stream effect only, because synoptic-scale and local-scale weather conditions during the two periods were inevitably not identical. The stream effect on air temperature is also evident in the temperature distribution along a street traversing the stream. In the daytime after the stream restoration, the sensible heat flux was greatly reduced and the ratio of sensible heat flux to net radiative flux dramatically decreased. These first-time results of the restored-stream effects on urban thermal environment could contribute to the scientific basis of urban planning which aims to make a large city comfortable to live in and nature- and environment-friendly.