ARRN Forum. Tokyo 2007. 11. 30

River Restoration in Korea-The past, the present and the future Kim Sukhyun. DirectorRiver Planning Division of MOCT. S.Korea

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CONTENTS
 The Situation of Rivers in Korea
 Examples of Restoration projects
 Conclusion
 Video (3minutes)

1. The Status of Rivers▶ Extreme variation of river flows▶ Deteriorated River EnvironmentLarge variation of seasonal precipitation▶ 65 % of annual precipitation concentrates in June toSeptember due to monsoon and typhoons▶ The variation is also big annually

200100D ec

N ovO ctS epA ug

Ju lJu nM ayA prM arF eb0Jan

R ain fall [m m ]300

Month4

Steep Slope of River Channel▶ Korean Peninsula has high mountains in the East andrelatively short length of rivers.
▶ Rainfall runs off rapidly into the ocean rather than being
absorbed into the ground

Elevation [m]

1,500
Tone
1,000

Han

Rhine

Roire
Colorado

500

Seine
Mekong

00500

1,000

1,500

Distance from River Mouth [km]5Extreme variation of river flow
▶ Conseqently, discharges are extremely variable throughthe seasons
9Ratio of discharges (Qmax/Qmin ) : 100 to 700

Monthly Average Runoff(1974 – 2003)
6

Fast urbanization deteriorated rivers▶ Rapid industrialization led to fast urbanization whichcaused urban land shortage during 1960s - 1980s.

√ The rate of urban population is 90 %▶ Many of the rivers lost their natural appearances√ Natural river lines have been straightened√ covered up with concrete for traffic or parking lots7

Original natural rivers in the past8

Deteriorated Example 1 : Parking lots in river9

Example2 : Straightened concrete channel

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Example 3 : rivers covered with structures

Cheongyecheon (2003)

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2. River Restoration in Korea▶ History about river environment▶ Examples of diverse restorations

History of River management in Korea▶ Before 1980’s: focused on flood control and water use√ River bank had been straightened and covered with concrete√ River environment was considerably deteriorated▶ After 1990: river environment became a matter of interest√ Public asked for improvement of river environment√ Demonstrated some pilot projects of river restoration▶ After 2000: build a system to restore rivers√ Revised River Act : river environment implementation√ Published River Planning & Restoration Guideline

13The basic principle by revised River Act▶ map out rivers by zoning system for management
9Conservation zone for well reserved river areas

9Restoration zone for damaged river areas

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Leisure zone for citizen’s activity and amenity

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G

reen

BlocksExample 1 : Restoration of yangje-cheon in Seoul cityRi

prap+Gab
ionnityBntr id
Pla mmuoCgeBrushOpen Biotope
Mattresseykiontg•`ateg
DBoulderRiprapev
Bare
Water tione
Ripap+riul ddW
Purifica
Boill eV-shape Ripple
Fet onS
Alternate Boulders
ap
Riprap+Gabion
er RiprdluosBg
Green Bai ngpp rs
SteouldeB

Closed Biotope

0 105015

Transition of Yangjae-cheon

Before (1996)

After (1997)

After (1998)
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Recent View
17

Recent View
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example 2 : Osan-cheon Restoration Project

Before (1999)

After (2001)
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Exanople 3 : Gyeongan-cheon Restoration Project

Before (2001)

After (2003)
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Example 4 : Anyang-cheon Stream Restoration Project

Before (2001)

After (2003)
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Example 5: Hagi-cheon Stream Restoration Project

Before (2000)

After (2001)
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Example 6: Gyeong-cheon Restoration Project

Before (2003)

After (2006)23

Example 7: Restoration of saji-cheon

Before (2002)

After (2004)

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3. Conclusions▶ Problems to be solved for river restoration▶ Conclusions

Problems to be solved for river restoration▶ Water Pollution should be cleared
In late 1980s, water pollution was in the worst situation
9 Since then , improved gradually
9 But still not satisfactory (annual average BOD 1.5-2.5)
926

▶ Serious variation of river flow should be relieved
In spring , many of rivers are dried
9 But in summer, we almost always suffer from flood927

▶ Quantitative evaluation of ecological enhancement byrestoration projects should be verified

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Conclusions▶ River restoration is indispensable for river environment andfuture generations▶ And we have to maintain a good balance between flood
safety, ecosystems of river front and citizens needs▶ However we can not achieve this projects without
cooperation of all participants such as regional governments,environmentalists, engineers, and citizens

29Cheonggye-cheon Restoration Project in Seoul

Before (1959)

Before (2002)

After (2006)30

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Thank you!

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