Many delta and coastal cities worldwide face increasing flood risk due to changing climate conditions and sea level rise. The question is how to develop measures and strategies for existing urban coastal areas that can anticipate these slowly changing conditions, such as gradually increasing sea levels and extreme river discharges. There is growing recognition that the increasing vulnerability of urbanised delta and coastal cities is strongly related to urbanisation, changing socio-economic conditions and human-induced land subsidence. Consequently, in response to climate change, it is likely to be most effective to adapt existing urban environments and urban assets, and promote flood sensitive behaviour in combination with prevention based approaches, aiming to improve the whole capacity of the urban system to deal with changing and more extreme conditions in the future. This approach is known as the resilience approach. Although there is much focus on resilience in research and practice, it still lacks knowledge on the effectiveness of measures, and increasing coastal flood resilience is mostly understood in terms of risk reduction and not yet as an opportunity for change and creating liveability. In addition, it lacks knowledge on processes of urban development, management and change at the neighbourhood level as an important condition for creating coastal flood risk resilience and to create added value. The main research question of this thesis is therefore twofold: “how can we adapt existing coastal urban waterfront areas to changing climatic circumstances and how can we take this adaptation process as an opportunity for creating added value?” When adapting urban environments three challenges can be identified. First of all, it is necessary to understand under what conditions coastal urban systems become less resilient and adaptation is needed, and what (combinations) of measures are most effective to improve resilience. Secondly, key to the successful adaptation of urban environments is effectively using moments of change in urban development and management as windows of opportunity for low-cost adaptation, and to yield additional benefits. This requires a better understanding of the opportunities to spatially and in a timely manner, synchronise adaptation measures with investments in urban development, urban management and infrastructure maintenance projects at the neighbourhood level. Changes can be both incremental, for example building renovation cycles as an opportunity for retrofitting flood resilience measures into buildings, or can be transformative, for example by using urban redevelopment projects that create new options for adaptation. Finally, a major challenge of adapting existing urban environments to the effects of climate change is that it requires anticipating long-term trends and changes that easily exceed periods of 50 to 100 years. This brings large uncertainties into the design and planning process. When facing deep uncertainty it is necessary to improve flexibility. Improving flexibility can be either tactical-operational (designed) or strategic (planned). Designed flexibility can be achieved by developing design that anticipates, or can adapt according to future conditions or functional requirements. This can be achieved by incorporating modifications in the design, through preserving space, by over-dimensioning critical elements or by built-in redundancies. On a strategic level, flexibility can be achieved by developing sequences of adaptation options that keep options open in anticipation of future conditions. Sequences of adaptation options (pathways) that are reversible and offer multiple options to adapt should be favoured over irreversible and non-flexible paths. To answer the research question, this research applies a resilience based planning method (the Adaptive Pathways Method, or APM) to develop and assess adaptation pathways at the level of neighbourhood development in two flood prone waterfront cases in Rotterdam. APM is a structured, iterative approach based on defining the conditions under which policy objectives are no longer attainable and adaptation is required, and the assessment of sequences of adaptation actions. It enables policy makers to explore and develop adaptive strategies The case study research in two flood prone urbanised areas in Rotterdam showed that Rotterdam’s land elevation policy for new building plots is expensive and offers no solution to reduce the flood risk of existing homes and businesses in the area. In this study, two alternative solutions (water robust and keeping water out) were developed and tested for spatial integration, (cost) effectiveness and opportunities for creating added value. The Feijenoord case shows that a district-wide flood protection strategy provides the most beneficial solution and opens up opportunities for capitalising on investments in waterfront development and improvements of the urban realm. The Noordereila
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