Urbanizing river deltas are highly susceptible to sea level rise and extreme weather events such as floods and droughts. Water-related disasters are already happening more often due to climate change, rapid urbanization, unsustainable land use and aging infrastructure threatening a large fraction of human and natural environments in these low lying and sinking areas around the globe. As stress levels of climate change are accelerating, societal and physical transformations are essential for adapting our deltas to climate change. In the Netherlands, imagination and evidence by design in the form of a long-term spatial vision, played a pivotal role in the past century to set, share and accomplish a new direction to overcome flood disasters by altering the coastlines and riverbeds of the Rhine–Meuse–Scheldt delta. The unprecedented rainfall in July 2021 and the storm in December 2021 which hit Western Europe revealed the effectiveness of this new direction. We therefore plea for a prominent role of design in climate science and delta management to imagine, analyse and communicate future perspectives for climate adaptation in urbanizing deltas.@en

Within the global transition to sustainable urban water management, Dutch polder cities are also contemplating revitalising their water traditions. One of the keys to this task is to integrate water management into urban design, which is explored but not yet practically instrumentalized in the urban design process. This article introduces the concept of hybridity and develops a Hybridity Design Approach as an interdisciplinary methodology to explore the possibility of realising the extreme low impact Closed City Concept. Integration of the water environment and urban space needs interdisciplinary cooperation and sharing knowledge, as well as an innovative way of thinking about water-resilient urban design, maximising the landscape quality of a polder city while minimising its hydrological footprint in the region. Effective visualisation tools and techniques for this collaborative design process are developed and tested in the area of Zevenkamp in Rotterdam.@en

Driven by population growth and rural migration toward the cities, the demand for affordable housing continues to increase. However, due to the scarcity of urban development space—especially in coastal areas, the supply is limited. As increasing land availability is one of the most effective ways to reduce real estate costs, this interdisciplinary research explores the alternative of urban expansion toward the adjacent marine environment of coastal cities. It focuses on floating residential dwellings from both technological and urban planning perspective, aiming to include the waterfront of coastal cities as viable, sustainable, and affordable alternative for urban development. The research takes on one of the most expensive cities in the world, Tel Aviv-Yafo, as a case study for increasing the supply of affordable housing in addition to vital sustainable future growth in the adjacent marine environment.

@en

Coastal dikes have been built for millennia to protect inhabited lands from exceptional high tides and storm events. Currently, many European countries are developing specific programs to integrate the construction of new dikes (or the raising of existing ones) into the built environment to face sea level rising. Technical difficulties in succeeding in this operation are questioning the paradigm of protection for the long term, pointing out the need for alternative strategies of adaptation that are not yet fully explored. This paper elaborates on innovative models to deal with coastal flooding, presenting the results of an interdisciplinary research and design process for the case-study of Southend-on-Sea (UK). Detailed numerical simulations are used to develop a spatial strategy to accommodate water during extreme events, introducing different prototypes of dike designs that include seawalls, enhanced roughness through rock and stepped revetments, as well as vegetation. The overall goal is to push forward the traditional approach of planning water protection infrastructure within the solely field of civil engineering. It elaborates on the integration of the disciplines of spatial design and engineering and presents novel advances in terms of spatial design for the revetment of overtopping dikes.@en

Exhibition at Gemeente Rotterdam, Timmerhuis, Rotterdam@en

Alle signalen wijzen erop: onze manier van bouwen en wonen in de delta is op de lange termijn niet vol te houden. Onderzoeker milieutechnisch ontwerpen en universitair hoofddocent aan de TU Delft Fransje Hooimeijer pleit daarom voor een radicale herijking van het deltabeheer. Een ontwerpende, interdisciplinaire aanpak is de eerste stap om de Nederlandse delta in de toekomst veilig en leefbaar te houden. En ja, dat levert soms provocatieve ontwerpen op.@en

Contribution to Redesigning Deltas, 100 jaar plannen maken, Het Nieuwe Instituut (2023) presentation of the RDD Design Study during the exhibition 'Nederland op de tekentafel. 100 jaar toekomstideeën'.@en

In dit ontwerp wordt Rotterdam door het uitbreiden van ring 14 een sponsstad met een eigen zoetwatervoorraad doordat de Maas een zoet binnenmeer wordt. Het opgevangen regenwater kan plaatselijk in de stad worden gebufferd. Dat maakt dat de stad kan voorzien in de eigen waterbehoefte. De haven valt buiten de ring en wordt geheel in de bestaande traditie in de toekomst opgehoogd om de economische motor blijvend te laten draaien. Elke dertig jaar zal een kavel worden opgehoogd en in balans met de natuur worden herontwikkeld.@en

The power of design is to be able to see beyond the existing reality and push its boundaries to new sustainable futures. It enables change in ways of doing that created the existing reality in the first place. It creates change. Redesigning Deltas investigates this power of interdisciplinary design in which urban, landscape, and engineering disciplines project a future on the basis of the natural and spatial qualities of the Dutch Delta. Redesigning Deltas is a collaboration involving the Delta Urbanism group and various faculties of the TU Delft, the Delta program, Deltares, Resilient Delta, Erasmus University, Wageningen University, and PBL. Redesigning Deltas employed several activities in 2022 of which one is the design study.@en

Venice is representative of the result of anthropocene acts on a vulnerable delta system. Therefore it is an excellent study case for a multidisciplinary team of TU students and tutors, to perform interdisciplinary research and design. Two visions were developed on the shared knowledge base to investigate ‘how do flood defense systems influence the spatial aspects of the territory in the context of a high dynamic landscape in the Anthropocene? ’The plan for the Perfect Lagoon is focused on tackling all of the current and upcoming problems where the emphasis lies on preserving and perfecting the lagoon in its natural assets by introducing a new dike system that enforces the natural ecosystem. It makes smart use of the sediment flows and tackles erosion. The interdisciplinary design is especially worked out in the section of the dike, where dimensions and functionality are designed from a shared engineering and landscape perspective. The plan Symbiotic System emphasizes the interconnectedness of the Veneto region in a sustainable way. The new transport/dam system will make the urban system more smart, it will be less burdensome, and give more space to the natural ecosystem of the lagoon. Both visions are a testimony of how flood defense systems have a major influence in the spatial aspects of the territory. Using the multidisciplinary approach, an integral design can be made for the flood defense, in which the opportunities for the territory can be first explored and then designed together with hydraulic infrastructures.@en

The latest IPCC report which is named ‘The Synthesis Report , Climate Change 2023’ was released on 20 March 2023 to inform the 2023 Global Stocktake under the United Nations Framework Convention on Climate Change. The report finds that ‘there is more than 50% chance that global temperature rise will reach or surpass 1.5 degrees Celsius between 2021 and 2040 across studied scenarios, and under a high-emissions pathway, specifically, the world may hit this threshold even sooner, between 2018 and 2037.’ These findings again emphasise the growing pressures and challenges that deltas are confronting in their path towards future development. It is evident that the global imperative for deltas to adapt has reached an unprecedented level, but at the same time the question arises if adaptation is enough. Especially considering the scope of societal challenges that need to be the point of departure for sustainable spatial transformation in general. Aren't they of such a fundamental nature that we need to reconsider our urban system as a whole and aim for transformation instead of adaptation? Looking more closely to the societal challenges we can organise them according to their environmental and socio-economic drivers. The environmental drivers are the climate crisis and the biodiversity crisis. The socio-economic drivers are ongoing urbanisation, the energy transition, and the new economy.@en

The undisputable human influences on the Earth’s system demand an urgent change of ways and transitions in human systems to sustain a healthy society in the future. Addressing the urgent climatic transformations in deltaic areas, this paper is an attempt of the Delta Urbanism research group at TU Delft to set the line for new (integrated) research inquiries by design and investigate fundamental, experimental, and strategic & operational responses to the existing prospects for action as a way to create collaboration between various sectors. These prospects for action are targeted at four critical fronts (climate, urban, governance, cultural) based on trends and challenges that deltaic areas are facing and to which coherent spatial strategies are needed. These fronts together need a research response to enable the making of the delta of the future through the power of interdisciplinary design. This perspective or prospect is established through six lines of inquiry that are elaborated in the paper. The central question is “how can the research field of delta urbanism provide a transformative ‘prospect for action’ to establish strategic pathways toward a resilient Delta future, where assertion and proof are synergized”? The discussion of the six lines of inquiry, which effectively address the four critical fronts, explores how they are poised to deliver fundamental, experimental, and operational outputs for further research and action.@en

The aim of the RDD Design Study was to explore the potentials of the synergy between spatial design and engineering (design) of the Delta territory to create a sustainable and safe Delta. The knowledge gap addressed is the lack of understanding of the mechanisms design thinking has to offer to generate interdisciplinary approaches. The scientific research question of the study was “How can spatial design support a transformative ‘prospect for action’ (handelingsperspectief) in delivering pathways to a resilient Delta future in which assertion (beweren/tekenen) and proof (bewijs/rekenen) are synergised?”

To this end 15 practice partners from the domains of urban design, landscape architecture and engineering were invited to work on 5 design challenges specific for the Dutch Delta system. The teams of urban designers, landscape architects and engineers worked on five challenges, or so-called moments in the Dutch Delta, were: Defacto, Vista and Arcadis (Limburg); Fabrications, Bosch Slabbers and Tauw (River Corrdor, Waal); Urbanisten, Lola and Royal Haskoning DHV (RTM Port); ZUS, Flux and Sweco (RTM Polder); and Studio Hartzema, Fedded-Olthof and Witteveen & Bos (Zeeland).

The teams were supported by experts representing various domains (covering social sciences and economics) to work in multidisciplinary groups delivering an interdisciplinary strategy that addressed the design question: What is a visionary future (and pathways to get there) for the Dutch Delta where life, work and recreation can be safe and sustainable in a climate-responsive territory from a systems perspective, considering the environmental and socio-economic challenges? How to envision and support this with plausible arguments on the basis of sound principles and design strategies? The Design Study consisted of masterclasses, local ateliers, public presentations, and methodological workshops with the aim to reveal the impact of design thinking in creating new research directions and governance challenges.
@en

Niet-duurzame economische en stedelijke groei en klimaatverandering vergroten de urgentie om onze huidige praktijk van deltabeheer radicaal te veranderen. Het is belangrijker dan ooit om nu al te beginnen met het opbouwen van kennis die nodig is om nieuwe vormen van beheer te ontwikkelen. Deze zullen het huidige systeem van ruimtelijke ordening ingrijpend beïnvloeden. Om kansen en risico's te verkennen, is de TU Delft samen met Deltares, Resilient Delta, Planbureau voor de Leefomgeving (PBL), Erasmus Universiteit Wageningen een ambitieus, interdisciplinair en meerjarig programma gestart waarin ontwerp en ontwerp gebaseerd onderzoek centraal staan: Redesigning Deltas.@en

Spatial design integrates social, cultural, economic, and political perspectives with natural site conditions and man-made construction to plan for sustainable urban development. The current flood-risk-related challenges induced by climate change place pressure on designing cities in which both natural and man-made conditions can be imbalanced. Creating a purely engineered line of flood defense to restore this balance does not always work. The idea of living more closely with water includes the discipline of spatial design more into flood risk management than the current dominant paradigm. Following the probability approach defined as risk = probability × consequences, the current Dutch paradigm is focused on reducing the probability with dikes; the United States focuses on reduction of consequences by evacuation and recovery. This chapter focuses on urban design and planning strategies for reducing flood risk not just by a flood defense line such as a dike, but also reducing risk by means of urban development behind the dike. Integrated urban flood design must integrate site-built environment characteristics and natural systems, and simultaneously solve challenges posed by hazards. Effective design, therefore, must be conducted on the basis of hydraulic engineering knowledge, leading to spatial designs that introduce resilient urban qualities. Two cases for this approach are presented and compared: Vlissingen, the Netherlands and Galveston, Texas, United States.@en

In a world influenced by climate change and consequently sea-level rise, extreme floods are expected to become more frequent in the future, representing a serious threat for riverine and coastal settlements. Therefore, flood protection is a large component of climate adaptation and should be closely related to other measures of climate adaptation and societal needs. In this context, SARCC (Sustainable And Resilient Coastal Cities) supports the use of integrated Nature Based Solutions into coastal management, urban planning and design, integrating them into existing infrastructure and flood defenses. This paper will focus on the strategy developed for Southend-On-Sea (UK), presenting the different approaches that were used to manage coastal flooding and make it part of a long-term large scale urban development strategy. In particular, this study estimated overtopping discharges during extreme storm conditions and analyzed their inland propagation using Delft3D FM numerical simulations. Based on these results, mitigation, and adaptation measures as a part of the spatial strategy were developed through a joint collaboration of hydraulic engineers, urban designers, maritime archaeologists and local authorities, pointing out the strength of interdisciplinary approaches for reliable and well-integrated flood protection strategies. Important highlight of the study is how flood risk management is integrated in spatial planning and how hydraulic engineering modeling is directly use as indicators to make spatial design decisions.@en

Mean sea level rise (SLR) could increase up to 2m by 2100, which would see damage caused by coastal flooding in Europe increase from €1.25bn per annum currently to €961bn in just over 80 years. Urban areas situated along the North Sea coastline are particularly vulnerable to extreme sea level rise (a combination of SLR, tide and storm surges). The main goal of this study is to assess the paradigm shift in flood risk management from reducing probability of the flood event to reducing its consequences in the city of Vlissingen, in the Netherlands. Two spatial adaptation strategies are modeled and compared by using spatial, climatic, and socioeconomic projections for the year 2100: the “Vlissings Model” and the “Spuikom Model”. The Vlissings Model is about increased coastal protection through the heightening of existing grey infrastructure by 3 m, which includes the dike and buildings constructed on top of it. The Spuikom Model is accepting and rerouting overtopping water towards an existing former backshore water basin. The study brings forth an interdisciplinary "Design & Assess" framework that brings together design strategies with flood damage models and cost/benefit analyses to compare the effectiveness of two paradigms in dealing with extreme SLR. Results show that raising the dike would ensure full protection from extreme events against an initial investment and maintenance cost of €215 mil. Accepting and rerouting overtopping water would, on the contrary, reduce the impact of the flood to €8,6 million damage and less than a hundred affected inhabitants, without requiring the construction of major infrastructure but of a flood retention basin integrated to the new urban development. On the other hand, the comparison between the two strategies remains complex in quantitative terms given the different cost-benefit assessment models for such interventions.@en

Het Centrum voor Ondergronds Bouwen (COB) en TU Delft hebben samen met de Vlaamse Overheid een ontwerpstudie naar de mogelijkheden van integraal en multifunctioneel ruimtegebruik binnen verdichte steden in Nederland en Vlaanderen uitgevoerd. Hiertoe zijn zeven consortia aan de slag gegaan met 6 wijken in 3 Nederlandse en 3 Vlaamse steden die allemaal een specifieke positie in het bodemwatersysteem innemen. Interessant aan de uitkomsten is de definitie van de problematiek op basis van deze positie in het ontwerpen van de doorsnede van openbare ruimte, ondergrond en gebouw.@en