Mitigation of Thermal Environment by Cheonggye Stream Restoration in Seoul, Korea

The restoration project of Cheong-gye stream is not just a part of Seoul's urban planning but a greater task that the entire nation is interested in as a symbolic project to revive an important part of Korea's historical and natural heritage at the start of the 21st century. When the project is successfully completed in September 2005, the capital will turn into a city friendly to both the environment and people. The restored Cheong-gye stream will also take an important role in the change of thermal environment of the city. That is expected to help mitigate Seoul's thermal stress, change hydrology, and street-level wind fields. To monitor and predict of urban climate change by the restoration of the Chejong-gye stream in Seoul, long-term meteorological monitoring system was constructed like Automatic Weather Station (AWS) and temperature and humidity data logger around this area. Especially, intensive observation has performed in this area by using temperature and humidity data logger (HIOKI), Net Radiometer (CNR), 3-Dimensional Sonic Anemometer (CSAT), temperature and humidity measurement system (HMP), and Scintillometer to understand the changes of thermal environment before and after restoration. A third intensive observation is scheduled for 7-12 August 2005 and the post-restoration monitoring will be carried out until 2006. From these routine and intensive observations, we can understand the thermal environment with respect to the change of land-use using by the data of AWS and HIOKI in Seoul, the characteristic of temperature and humidity by deploying a network sensor across a Cheong-gye stream area, the vertical wind profile by CSAT, and the energy balance by sensible heat flux and net radiation observations using Scintillometer and CNR. Cheong-Gye stream restoration is expected to the mitigation of urban heat island in Seoul.