LANDSCAPE REGENERATION: Inherit And Develop Traditional Eco-wisdom of Polder Landscape In Yangtze Watershed

Tongji University, Shanghai, China
Personal Capstone Project, supervised by
Daixin DAI & Lin ZHANG

Polders are a wise response of ancient Chinese to the lowland environment in Yangtze watershed. Nowadays, the fact that prominent land-use type is converted from polder to new town has resulted in aggravation of the flood risk, decrease of biodiversity and invalidity of the original human settlement.

Aiming to reintroduce the traditional eco-wisdom to the New Town construction, I summarized the mechanism of the conventional polder landscape based on literature review and on-site survey. I found out that efficient coupling of three subsystems, namely flexible stormwater management, efficient land-use, and polder-based community, provides the driving force of the landscape regeneration.

According to the mechanism, sustainable strategies of ecological planning and design were proposed for the case of Hangbu New Town in Shucheng, China: (1) low impact development strategy by reusing the stormwater management system of original polder landscape, including maintaining polder banks, dredging river channels, and appropriate zoning; (2) enhancement of ecosystem services by conservating native plant communities and constructing greenway on polder banks; (3) build open residential community based on the polder banks.

The conclusion can be drawn that new town planning should refer to the traditional polder wisdom in terms of the integrated organization of stormwater, land-use and human beings.

Conceptual Model of Polder Landscape Regeneration Mechanism
In agriculture period, the landscape regeneration results from the coupling of economy (agricultural production), environment (ecosystem), and society (farming society), while new balance among the three subsystems should be built  in the newtown construction through good  conservation of the pivotal spatial pattern of the current polder landscape.
Urban Flood-management System in Hangbu
To build an urban flood-management system in new towns should follow the conventional strategy of hierarchical banks, which can decentralize stormwater control and decrease flood peak. The first class refers to urban rivers and suburban natural wetlands, where rainwater will finally be drained. The second class is composed of creeks which originally exist or newly excavated. Bioretention, the third class, plays a role as capillaries in collecting the runoff inside the built environment.
Master Plan: the Northern Wetland Park
Design Strategies
Flood-adaptive Landscape Design
the Polder Banks as Greenway
Detailed Design
Flooding Scenarios