Planting Design 2013 Working Group 6 - Case Study A
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Cheonggyecheon: Image of Nature in the Metropolis
| Name | Cheonggyecheon | |
| Location | Seoul | |
| Country | Korea, Republic of | |
| Authors | Hyeyoon Choi | |
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Rationale: Why is this case interesting?
There was historical restoration of a small stream, Cheonggyecheon, in the center of Seoul in 2003. Right now, Cheonggyecheon is very famous landmark in Seoul and citizens and tourists love this place. However it looks more like “Disneyland-fication” than natural stream restoration. Environmental activist criticize the output of restoration because it is far from natural stream and costs a lot for maintenance. Cheonggyecheon is still controversial issue. The appearance of restored Cheonggyecheon is ideal but not practical. I have never been living out of City, and actually I have spent the most of my life time in Seoul, huge metropolis. As a result, I am not sure how to implant Image of Nature in the City Area, where a prototype of nature can merely survive. Studying the restoration project of Cheonggyecheon, I want to look for the answer of it.
Author's perspective
From which professional background/perspective are your documenting this case?
I was born in developing country and live in developed country. Based on my experience in high speed urbanization, I try to light on the image of urban stream. As a civil and environmental engineer, it is impossible to overlook the natural function of the stream in restoration project.
Landscape and/or urban context of your case
- Biogeography, cultural features, overall character, history and dynamics
Cheonggyecheon is natural ephemeral stream across the city of Seoul, which has been the capital of Korea since 1392, and functions as discharger of heavy rainfall in summer monsoon. It has been dredged for the sake of preventing flood for more than 600 years and its name, Cheonggyecheon, is also originated from the meaning of “dredge a stream”. In 1770s, the stream was straightened in the process of dredging. After Korean War, the poor people settled nearby the stream and it had been slummed through the age of industrial revolution. The stream was extremely polluted by chemicals and sewage. The stream had been covered up since 1930s and the overpass was constructed over the stream in 1970. In 2000s, according to deterioration and safety problem of the overpass, the government of Seoul city decided to restoration of Cheonggyecheon and the construction was fulfilled in 2005 followed by 26 months of rushing construction. 270Million Euro had been spent to restore 5.8km long stream. The running waters are leaded from groundwater fountain in subway and the Intake station in Han River because there is naturally no running water on the stream except monsoon season.
The restoration of Cheonggyecheon was planned to connect biotopes in Seoul. The CBD, Cheonggyecheon cuts through, is surrounded by Mountains and palaces functioning core patch of ecosystem and the end of Cheonggyecheon flows into Han River. The restored stream is vertically consisted of wetland, flood plain, revetment, and the terrace land and the large range of plant from submerged plants to roadside trees was planted on each site. 288 species of animals and 366 species of plants inhabit along the stream.(2012, 7th Han River Ecology Report). The upper region has a simplified water bed and the velocity of fluid is quite high. The plants bed is well manicured but the lack of diversity is remarkable. The feature of inhabitants becomes more natural toward the mouth of the stream and at the mouth of the stream is only area where amphibian and reptile live.
The starting point of Cheonggyecheon is sited on historical center of the Seoul, inside of the old castle. The upper stream is mixed zone with the historical palaces and high-rise buildings so it is conceptualized as historical and tradition section. The stream flows into the Han River and the mouth of the stream has abundant natural resources, and this area is planned as natural and future section. The middle of the stream lies on very hot market place and became a cultural and modern section. The direction of restoration does not completely correspond to ecological restoration but Cheonggyecheon gains great popularity as urban park. Especially the upper areas are used for festival, exhibition, and routine trail for citizens.
- Illustration
1930s
Slummed Area before cover-up
Overpass from 1976 to 2003
Restoration Plan
Analytical drawings
Please add four analytical sketches/drawings (or montages/schemes) of your case and take the following aspects into account:
- natural dynamic versus cultural framework - in how far do these two forces come together in your case?
Image of nature reflecting on the restoration of Cheonggyecheon shows that it is almost impossible to reproduce the nature already ruined. Although the rebirth of Cheonggyecheon means the change of paradigm about value of nature in society, it still remains in the object that people uses and enjoys. The nature is reinterpreteted without primitive function and dominated by cultural text as what is like in their imagination. Practically it is merely possible to recreate primitive stream in the center of highly concentrated urban area. About 50% of Koreans live in metropolitan area, inside of and nearby in Seoul, and 20% of Koreans live in Seoul. The areas that Cheonggyecheon laid on is the most highly developed areas. It is merely founded unpaved ground except palaces and mountains. The percentage of impervious areas in Cheonggyecheon reaches 71.5%, the highest among all over Korea(2013, Ministry of Environment). This means that it is very hard to have quantity of natural flow in the stream, which is supposed to be in native condition. The high-rise buildings are standing along Cheonggyecheon and the mid-stream areas are very crowded market area. In the process of the indemnification for land has born acute social issues. After covered up in 1930s, the areas over the stream had been specialized commercial complex for industrial tools and gears. The Restoration of the stream forced it out of Seoul and many small businesses lost their livelihood. Cheonggyecheon was rebuilt between limits of reality, in which living nature could hardly survive. The result is destinated costly operation and maintenance caused by pumping water up, released fishes confronted by death, and ecosystem interfered by people who want to enjoy new Disneyland.
According to recent research about the ecological datum in Cheonggyecheon and Han River, the upper areas are close to urban entertainment facility and the downstream areas fulfill the conditions to be a natural stream. The upper area has very neat scenery with big limestone but it does not fit on condition for the natural stream and it functions as urban waterfront. The sediments are deposited along the stream and results the better surroundings for native creatures. Furthermore the downstream has pretty much larger flood plain and the spot connecting to Han River, Eco-reserve areas. Thorough the full range of the stream, there is no regard for bird habits and benthic macro-invertebrate. Culturally the upper stream is surrounded by CBD and huge market area and the downstream passes by residential areas. For this reason, the upper stream was planned to be historical and traditional place, even though the results does not seem like that. The upper stream is used for open place for citizens rather than for animals and plants and hundreds festivals and ceremonies are held yearly.
The restoration was projected to develop green network in Seoul, which connect the mountains in south and north including the palaces nearby and complete the circular corridors to Han River. It is devoted obviously to ecological richness but is barely said to accomplish green network. In spite of controversial situation, Cheonggyecheon contributes greatly to lower the temperature of CBD area in Seoul, averagely 3.6℃ cooler than other areas in Seoul, and provides a green place that citizens are relaxing and enjoying.
- dynamic through the year (you may imagine how the site looks in spring and summer, maybe you also remember it)
The upper stream close to my living place always stays in the same image in my memory through the year because it looks like big fish-ball. There are big exhibition like lantern festival in winter time and children having fun in the water in summer. You could see people chatting with their colleagues in daytime and taking a walk along the stream at night on the way from their work. The critical reason that the stream could retain its neat outlook is cleaning service by city government. The stream was maintained like government building through sweeping and rubbing.
- highlight potentials and problems
CCheonggyecheon has little quatity of flow because it is originally a dry stream and the large of the basin is impervious. In a result, it artificially pumps water up from Han River and underground. The drawing process costs averagely 600,000EUR per year. Furthermore this operation causes water-bloom. The cost for maintenance was 6,000,000EUR in 2011 and has increased continuously. On the other hand, impermeable covered-up pavement in CBD nearby Cheonggyecheon intensifys over-flood in summer monsoon. Followed by climate change, the amount of rainfall in summer monsoon increases dramatically and features pouring a large amount of rainfall in a short period of time. Additionally huge size of square was built nearby with waterproof material and is sunken in the rain . This situation drives disputes about natural function of the stream as a discharger.
- Analytical Drawings
Connecting Biontopes in Seoul
The Upper areas of stream
Toward the mouth
Four Seasons
Projective drawings
- Please add four projective sketches/drawings (or montages/schemes) for your case and take the following aspects into account:
- How would you like this case to change in the near future? (in 1-2 years)
- And how could it look like in 10-15 years?
It is surprised that the downstream of the stream achieve desirable condition and worried about the interference by human being. To preserve stable ecosystem, limit access area should be set up partially. In case of the upper stream, well managed garden hazards variety of species so changing a planting plan is advisable. To enlarge unpaved areas and planted areas would be helpful to improve the situation. However, it will be needed more land for flood plain in long term. The stream has 10-30m width of water way, 3.7-12.8m width of flood plain, and 12.5-16.5m box structured road beside which has empty space inside used to extra flood plain at the same time. This roads are designed to be converted into water bed in case of need. Overall, the downstream should keep its condition well and the upper stream should be like the downstream.
Seoul metropolitan government releases their plan to re-restoration of Cheonggyecheon yesterday (29 Nov. 2013). The core issue of the plan is to dismantle straightened water way, and to make a meandering. Furthermore the plan includes reconstruction of historical monument carried away and alternative water resource flowing on the stream. The plan is going to be confirmed next year and go on until 2050. Considering climate change, this plan should deal with deep underground reservoir or rain garden to evacuate heavy rainfall in short time and release it gradually in case of need.
- Projective Drawings
Overflow in summer
Rain Garden
Underground Reservoir
Enlarged flood plain expected in few years
Summary and conclusion
Please summarize your case and give arguments for your projective design (approx 150 words).
In long term strategy, even thought the restoration of Cheonggyecheon was partially failed, it is big foot print as the first step forward. The story of restoration was a heritage of high-speed development era but left a great potential to evolve that matches paradigm changes. In the circumstance of tangled interest, oppressive and dogmatic development was inevitable at that time. However, climate changes enhance a necessity of urban discharger and a consideration of sustainable development draws the plan for re-restoration. Acquiring proper quantity of flow from natural resource roots the issue of impermeable space and loss of small stream in urban area. Technical resolution like urban garden and deep underground reservoir would be dealt with to relieve this issue. Furthermore, the roads along Cheonggyecheon should be transferred to flood plain. The positive outcomes from restoration, relief on heat island, ecological contribution, and even its entertainment job, would support further steps forward.
Image Gallery
You may add a series of images/photos in addition to the sketches/drawings
- Image Gallery
Standard Cross Sectional Drawing
Planting Plan
- Yourfilename4.jpg
image 4
References
* Discovery Documentary about the Cheonggyecheon Stream http://www.youtube.com/watch?v=_zSFZ2dGl4g
* Seoul Metropolitan Government(2006), The Restoration of Cheonggyecheon White Paper
* Seoul Metropolitan Government(2012), The Han-River Ecology Report
* Seoul Metropolitan Government Press Release
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