Sea levels are rising globally and the melting Antarctic ice sheet is attributed to be the primary contributor. Due to the deep uncertainty of the causal representative carbon pathways, the plausible range of sea levels rise varies between 0,26 - 2,43 m for 2100 and 0,50 - 15,52 m for 2300. To address deep uncertainty, decision making methods arise which struggle with including measures preparing the shift from incremental to transitional strategies required for the case of extreme sea level rise scenarios. This research addresses flood risk management in the Netherlands, a country which will face ecological, economical, technological and political challenges as sea levels climb. In anticipation to extreme sea level rise and its challenges, the Dutch process of coastline shortening and solidating can be carried through. Another viable option is a more gradual zone between land and water. To review both options, the distribution of systems sensitive to flooding is mapped. The overlay of systems facilitates the establishment of a framework which distinguishes elements based on their pace of transition and offers a multilayered image differentiating regions with an emphasis on either population or nature. This dichotomy structures the proposal for the transitional territorial outline by harmoniously applying a superimposed coastline and a dynamic coastline respectively. Tipping points of flood defence measures assess the physical feasibility of the transition which is mainly constrained by societal limitations. This results in incremental improvements, further increasing transfer costs, path dependency and the difficulty to shift to transitional strategies. Throughout history, only catastrophic floods were leading to transitional flood measures, but transition management is referred to as enabling development of a long-term sustainability perspective, linked to desired societal transitions, to guide accelerated social innovation in the short term. The theory’s transition arena with frontrunners and a transition image is capable of opposing the resistance-giving, established standard and is instrumental for communication, discussion and evolvement of the transition of flood risk management.

Water is cherished as treasure in traditional Chinese culture and expected to stay in harmony with human. However, the disharmony between water and urban life is looming especially after over thirty-year rapid urbanization in China with notable global climate change. Faced with water-related issues, e.g. flooding, water pollution, water shortage, etc., Government of China initiated a so-called Sponge City Program (SCP) in 2014 for constructing ‘sponge-like’ water-resilient cities. Nevertheless, challenges and gaps lie in practice of SCP, one of which is that an operationalizable design approach of a sponge city to realise its multiple objectives is neither available in current guidelines, nor thoroughly studied or proposed in recent literatures. The aim of this master thesis was to formulate an improved approach, as well as to improve planning & design framework for supporting integrated sponge design process and enhancing the involvement of various stakeholders. Literature study, the study of current guidelines and sponge plans of Nanjing, and interviews with sponge city practitioners were performed to evaluate current Sponge City (SC) concept and assess SC planning & design practice. Analysis of SC concept development showed that SC has been evolving from a term mainly describing measures with ecological benefits towards a more inclusive urban development paradigm, considering not only water ecology, but also water safety, water environment and water resource. Analysis on SC practice identified the gaps in current SC water management contents, including a lack of design method for calculating storage capacity against pluvial flooding, ignorance of extreme drought assessment, missing groundwater management, etc. Challenges that might impede comprehensive sponge city planning & design process were also enumerated, including data availability and accessibility, the bond between SC and other sector plans, etc.  Based on the identified challenges and gaps, improvements on current planning & design practices were given and a new design approach was proposed, including changing collaboration method, introducing a co-design workshop and using a sponge design toolbox to facilitate planning & design process. The approach provided a method to calculate the required sponge capacity for not only preventing flood damage but also mitigating water shortage in dry spells, as well as quantifying other co-benefits. The improved design approach was tested by a case study in Nanjing, in the Qinhuai District sponge city planning project. Case study results showed that most steps in the proposed design process were successfully taken in Qinhuai project, and the toolbox was able to facilitate planning and design of sponge measures to have functions not only for pluvial flooding prevention and control, but also for water shortage mitigation, ecological benefits and other day-to-day values. The design process also demonstrated the collaborative contribution to a sponge city plan from water managers, water engineers and landscape architects. Therefore, the new design approach can contribute to a more integrated SC planning and design.

Urban climate adaptation currently focusses mainly on hazards but often ignores opportunities which arise in both space and time. Opportunistic Adaptation provides a rationalized approach to mainstream measures for climate adaptation into urban renewal cycles. Adaptation opportunities are identified by projecting the lifespans of urban assets into the future to obtain an operational urban adaptation agenda for the future. Upscaling of the adaptation process is done by synchronizing the end-of-lifecycle of a group of assets to develop adaptation clusters that comprise multiple dwellings, infrastructure as well as public spaces. An extensive catalogue of adaptation measures for different scale-levels ensures flexibility in the type of measures that can be integrated. Sequencing the adaptation measures over long periods of time provides insight and flexibility in the long-term protection standards that can be achieved. By applying a design-centered approach, the potentials of obtaining co-benefits in the urban landscape are maximized. Potentials of clustering of nature-based solutions are being considered which ensures to maximize the delivery of ecosystem services. This research aims to assess he adaptation potential of Bangkok, based on a case study area (Lat Krabang) by mapping the adaptation opportunities and flood vulnerability. The resulting outputs will contribute to the development of a flexible and inclusive FRM strategy.@en

The unprecedented growth of cities has a significant impact on future flood risk that might exceed the impacts of climate change in many metropolitan areas across the world. Although the effects of urbanisation on flood risk are well understood, assessments that include spatially explicit future growth projections are limited. This comparative study provides insight in the long term development of future riverine and pluvial flood risk for 18 fast growing megacities. For these cities a spatially explicit urban growth model has been developed capable to identify and extrapolate spatial development trends into growth projections for the short, medium and long term. For some cities like Dhaka or Lahore, the outcomes are alarming while others show an implicit tendency for flood adverse urban growth. The outcomes not only provide a baseline absent in current practise, but also a strategic outlook that might better establish the role of urban planning in limiting future flood risk.@en