Reprise de la rivière Han d'ici 2030 : coexistence de l'homme et de la nature
Introduction
Han River Renaissance Project, or the revival project for Han river aims to gradually revive the degraded ecology of Han river. It also seeks to provide a guideline for an efficient use and systematic management for the river. Designed to make the river full of life where nature and humans can coexist, the project was initiated after a 2-year (from 2012-2013) consultation process involving citizens, experts and other Stakeholders.
Making Han River Replete with Life
Unfortunately, indiscriminate development and overuse of Han river pushed the self-restoration ability of the river to its limit. Committed to recovering the river, citizens of Seoul and the city officials got together to plant trees and create an attractive habitat for many flora and fauna. Finally, the efforts paid back and those plants and animals that had once left Seoul came back. In addition, Han river is reborn a warm place for all citizens to come and rest.
Creating Three Types of Han River Forests
The city of Seoul plans to create Han River Forest, a dense forest that is 5 times bigger than Yeouido Park (1.047㎡) by 2030, by planting trees around Han River. So far, companies, civic groups and citizens have participated in planting trees around the area. The Forest will be composed of 3 different sections: ecological forest, community’s forest and buffer forest. The ecological forest is designed to restore the ecosystem of Korean Willows and reeds near the water’s edge while the community’s forest is composed of elm-like trees and bridal wreaths with great accessibility to citizens. Finally, buffer forest is built in buffer area under the riverside.
Restoring Habitat
Currently, much of Han river’s shore is straightened by artificial manipulation and riversides have turned to parks, leaving little or no room as a habitat for various types of birds and. To restore healthy biodiversity in the river, Seoul’s first objective is to identify the area of the river that has greatest potential to be the focal point for ecological diversity. Tancheon stream, Jungryang stream and Yeouido setgang are under consideration for their great accessibility with regard to earthmoving. The second objective for Seoul is creating a wetland which can serve as a great habitat for animals and plants. Possible areas for wetland are Ichon station and Banpo stream where flood risk is low. The chosen stream will be home to willow trees, sandbank, fishway, natural revetment and waterfront. The two objectives, when realized, will make Han river as a habitat with 3 focal ecological points (547,000m2) and 2 riverside wetlands (167,000m2).
Restoring Han River’s Ecological Network
Right now, the Han River Ecological Network is disconnected due to construction of riverside roads and streets. Once the Network is connected through Gangseo, Gwangnaru and Ichon (689,000m2), a meaningful network for ecology of Han river will be recovered. The goal of this plan is to increase the number of plant communities as well as multi-layer food plants by connecting Gangseo (Gaehwasan~Deogyangsan) in the West, Gwangnaru (Acha, Yongmasan~Cheoryangsan) in the East and Ichon (Yongsan~Gwanaksan) in the North and South through tree-planting methods. 4 Buffer green belts linked with ecological bases will be created and in the long term, these green belts will be associated with massive-scale development project of nearby cities in Han River in order to secure urban green belts in the riverside of Han River.
Creating Clean Water for Fish and People
Concrete revetment of Han River will be reformed to create fish way and to ensure water quality high enough for people to swim in the water.
Improving Water Quality and Securing Aquatic Plants
Drops refer to small-sized beams installed in the middle of waterway as a tool to control its slope and to stabilize water flow. In fact, single-structure drops made of concretes are located in the stream confluence where streams and Han River’s main streams meet. Unfortunately, the drops have caused water degradation and blocked the movement of aquatic plants. To address the problem, these single structures in 5 different confluences are planned to be replaced to stair forms. In the short term, Tancheon drops will be replaced, and in the mid and long term, other streams including Hongje, Banpo, Seongnae and Godeok will go through the reconstruction. The plan aims to improve the water quality and secure free movement of fish by recovering the flow of Han River.
Restoring Natural Waterfronts
Currently, waterfront structures are concrete-based, but soon they will be replaced with ‘natural waterfronts’ that is similar to riversides or with ‘natural-type waterfronts’ that is a scour area effective in flood control. Natural waterfronts are built by planting reeds, amur silver grasses and Korean willows after eliminating concrete retaining walls. It then goes through sedimentation, thereby creating waterfronts. The plan will be implemented only after a careful assessment of the impact on the environment and ecosystem. Ichon~ Dongjak Bridge, Jamsil Railway Bridge ~ Gwangin Bridge whose total distance is 9.8km with slow velocity are being considered for the construction sites. Stream experts will provide counseling and studies on scour area where earths and sands are carved out due to rapid velocity in order to change them into natural type waterfronts. 6 areas including Banpo and Yanghwa will have these new waterfronts worth 12.6km. The methods of eliminating concretes for natural type waterfronts are similar to that of natural waterfronts; however scour countermeasures as well as rocks are added in order to ensure flood control.
Providing Clean Water to Swim
In order to make the quality of Han river clean enough for people to swim, 199,000 m2 worth paving materials of parking lots and gyms will be replaced from impermeable to permeable materials. Also, 153 new green belts and 800 natural purification facilities will be established to block non-point pollutant resources and to improve water circulation.
Meanwhile, if gravels or plant purification system are placed at the bottom of slope bank, they can significantly contribute to blocking pollutant materials.
Expanding Participation Opportunities for Citizens to Improve the Environment of Han River
As part of an awareness campaign, Seoul will provide a variety of hands-on programs for citizens. At the same time, Seoul will divide the river into parts—area for the community and the area for environment conservation—and apply a differentiated management approach to each part.
Providing Opportunities to Learn and Experience Han River’s History and Culture
Seoul is excited to create a more interesting and novel opportunity for citizens to utilize Han river. For instance, Seoul is planning a program that enlists participation of citizens by storytelling. Those participating in the program will learn about some fascinating stories behind Han river’s history while view the amazing view from the river. A total of 1,250 of such programs will be provided in 8 different places to accommodate as many participants as possible.
Given that physically restoring the original landscape Han River is difficult, Seoul plans to utilize historical and cultural assets of the river, build outlook points as well as various theme based hands-on programs. The hands on programs will focus on Han River Railway Bridge, Nodeulseom and Seonyudo Island while outlook points will be established in Jeoldusan, Hyosajung, Yongbongjung, Eungbong, Namsan and Achasan.
Taking Three-Thronged Approach
Seoul plans to take a three-thronged approach to the use of Han river. To this end, Han river will be divided into conservation, restoration and user areas, and management policies will vary accordingly. For the conservation area, there will be access control and parts of the area will be required to be left in its natural condition without any human interference as a way to ensure that the ecosystem is not damaged. The second type, restoration area will have buffer zones, and access control will be applied until the area becomes stabilized. In the user area, access will be allowed but Seoul will make sure that no damage to the ecosystem is made. Along with this plan, the city will enhance participation of citizens by developing and operating eco-friendly programs.
Citizen Empowerment
When it comes to management of the river, the city government plans to empower citizens and civic groups, instead of giving all authority to some administrative agencies. Its goal is to engage and empower as many as 600,000 citizens by creating the Han River Water Council. Additionally, the Han River governance system will be established which encourages citizen participation in each stage of the decision making process. In the long the term, Seoul plans to create a greater Han river water council which is a network of all smaller, stream-based councils. The encompassing council should enhance cooperation and collaboration of all stakeholders. Additionally, Seoul is committed to create more voluntary activities and training programs as a way to nurture competent citizen leaders who can bring a better future to Han River Park.