Urban surface water system in coastal areas: A comparative study between Almere and Tianjin Eco-city

Abstract

In the purpose of defining typical urban water management challenges in coastal lowlands in the context of global climate change, a com-parative study was conducted between two coa-stal new towns respectively located in the Neth-erlands and Northern China. Comparative me-thod is applied to define main functioning pat-terns of urban water systems in the two cases, then computer simulations were used to further compare drainage capacity in order to reveal the trends of urban water management. Major result has shown that Almere in the Netherlands generally more advanced in urban water man-agement as multiple functioning patterns are available. Strong dykes maintain competence for land subsidence and sea level rise. Open water system decreases local runoff and increases water retention level. Systematic control of sluices and locks which serve for shipping and water-front landscaping are simultaneously isolating contaminants from outer water body. Tianjin Eco-city in China has shown both strengths and weaknesses. It takes large amount of reclaimed water as main landscaping water source, which adapts to local water pollution and shortage while requires highly centralized facilities. Large water body is reserved and huge scale under-ground drainage system built, but it is still vul-nerable to heavy storms due to the lack of effi-cient surface water drainage system. Coastal line control does not adequately prevent from in-creasing storm surge risks in the future. SWMM simulations have supported the viewpoint of dis-tributed surface water with a higher efficiency for storm drainage. Meanwhile, surface water system returns more added values to urban development. The study is corresponding well with the theory of water sensitive city. As a con-clusion, urban water system should always in-corporate methods to achieve higher system resilience based on multiple functioning pat-terns.