Flood Pulse Design Principles—A Time-Based Approach to Urban Flooding

Abstract

This chapter explores the potential of a time-based, nature-inspired approach to urban flood resilient design in the context of SeaCities. As a vast majority of existing coastal cities develop along continental shorelines and are in the proximity of rivers (accounting for freshwater supply, anchorage, etc.), coastal urban development is exposed to tidal, storm surge as well as riverine flooding. Based on historical effects of urban flooding, three key flooding hazards have been identified: damage to infrastructure, dangerous debris and loss of economic productivity. In contrast, within flood-adapted natural wetland ecosystems, the three factors which negatively impact the urban context represent positive ecosystem growth drivers within a range of hydrological regimes. By reviewing flood response mechanisms in relation to the three factors (examples from riverine floodplains, coastal salt marsh and estuarine mangrove forests), temporal correlations between local hydrological regime and ecosystem processes are identified as key drivers of flood resilience in the ecosystem. Based on the strategies identified within the ecosystem review and review of selected examples of current projects and urban flood protection strategies, the analysis concludes by speculating on how the ecological strategies and temporal correlations identified could be adapted into urban design principles. Proposed strategies are assessed in terms of mitigation of the three key flood hazards and the potential for exploiting natural flooding phenomena to generate new urban growth opportunities.