Sandy shores around the world suffer from coastal erosion due to land subsidence, a lack of sediment input and sea level rise. This often leads to the construction of hard structures, such as sea walls and breakwaters, that consolidate the coastal zone but disrupt the dynamic system of coastal deltas. To compensate for coastal erosion in a more natural and systemic way, sand nourishments are now increasingly executed. This so-called ‘Building with Nature’ (BwN) technique uses natural resources and dynamics to restore sediment balance within coastal zones and promote coastal regeneration and dune formation. These dynamic nourishment techniques are still in development, placing new demands on coastal spatial planning. How can we position and tune these nourishment dynamics for land formation; not only to optimize coastal safety but also to integrate these dynamics with the ecological and urban functions of the coastal landscape? An integrated design approach is necessary to guide both land-shaping processes and adaptive urban and ecological configurations to support BwN-based dune-formation following nourishment and boost the buffer capacity of coastal zones.

This research aims to develop design principles for integral coastal landscapes that connect geomorphological processes, ecology and adaptive urban design to exploit their potential for the spatial development of multi-functional coastal landscapes— shore-scapes. It focuses on coastal configurations featuring pro-active sediment management through aeolian BwN techniques to build up the coastal buffer in a natural and multifunctional way.

The first step was to reframe BwN nourishment design as a landscape approach, employing natural onshore dynamics to sustain the coastal buffer and increase the multiplicity of the coastal landscape. The coastal landscape can be regarded as the result of the interaction between the geomorphological, ecological and urban system, in response to sea level rise. The mapping of their interactions (via literature review, fieldwork, GIS and CFD-modelling), identified three potential spatial mechanisms to support nature-based dune formation following nourishment: natural succession, dune farming and urban harvesting. To activate these processes for coastal reinforcement and landscaping, and bridge the spatial and time scales involved, three subsequent tools for dynamic design were defined: morphogenesis, dynamic profiling and aeolian design principles.

In the second half of the research, the BwN landscape approach and principles were contextualized and tested across four case studies, which revealed how coastal system’s characteristics and nourishment strategy affect dune formation. Responding to various nourishment and urban conditions, spatial arrangements were composed that enhance the aeolian build-up of coastal profiles and landscapes over time, supporting dune reinforcement, multifunctionality and
landscape differentiation.

The outcome of this research is threefold. First, BwN was redefined as a landscape approach that employs intersystemic land-shaping processes to support coastal safety, multifunctionality and spatial quality. Second, a set of validated design principles was developed for natural aeolian coastal adaptation following nourishment. Third, spatial arrangements were composed to illustrate how BwN processes ashore can be guided in space and time across various nourishment and urban contexts.
@en

The incentive for this publication was to expand the realm of enquiry around the topic of Building with Nature (BwN), for two main reasons. First to gain an interdisciplinary, and therefore deeper, understanding of BwN as an object of study. Secondly, but no less important, is an understanding of how different forms of knowledge contribute to our learning regarding BwN. When we understand the contribution of several academic disciplines and knowledge from practice, we may eventually get to the point where we can identify how they can collaborate successfully to contribute to BwN as an interdisciplinary field.@en

Sandy shores worldwide suffer from coastal erosion due to a lack of sediment input and sea-level rise. In response, coastal sand nourishments are executed using ‘Building with Nature’ techniques (BwN), in which the sand balance is amplified and natural dynamics are instrumental in the redistribution of sand, cross- and alongshore. These nourishments contribute to the growth of beaches and dunes, serving various design objectives (such as flood safety, nature, and recreation). Nevertheless, human interference (such as buildings and traffic) along urbanized sandy shores may have significant, yet poorly understood, effects on beach and dune development. Better insight is required into the interplay of morphological, ecological and urban processes to support Aeolian BwN processes for dune formation and contribute to the sustainable design of urbanized coastal zones. This paper aims to bridge the gap between coastal engineering and urban design by formulating design principles for BwN along urbanized sandy shores, combining nourishments, natural dune formation and urban development on a local scale to strengthen the coastal buffer. The first part of the paper analyses sedimentation processes in the (built) sea-land interface and identifies spatial mechanisms that relate coastal occupation to dune formation. Hence a preliminary set of design principles is derived by manipulating wind-driven sediment transport for BwN dune formation after nourishment. In the second part of the paper, these principles are applied and contextualized in two case-studies to compare their capability for BwN in different coastal profiles: the vast, rural, geomorphologically high dynamic profile of a mega-nourishment (Sand Motor); versus the compact, highly urbanized, profile(s) of a coastal resort (Noordwijk). Conclusions reflect on the applicability of BwN design principles within different coastal settings (dynamics, urbanity) and spatial arrangements facilitating BwN dune formation.@en

This publication offers an overview of the latest cross-disciplinary developments in the field of Building with Nature (BwN) for the protection of coastal regions. The key philosophy of BwN is the employment of natural processes to serve societal goals, such as flood safety. The starting point is a systems-based approach, making interventions that employ the shaping forces of the natural system to perform measures by self-regulation. Initial pilots of this innovative approach originate from coastal engineering, with the Sand Motor along the coast of South Holland as one of the prime examples. From here, the BwN approach has evolved into a new generation of nature-based hydraulic solutions, such as mangrove forests, coastal reefs, and green dikes.@en

The long-term physical existence of sandy shores critically depends on a balanced sediment budget. From the principles of Building with Nature it follows that a sustainable protection of sandy shores should employ some form of shore nourishment. In the spatial design process of urbanized sandy shores, where multiple functions must be integrated, the knowledge and the prediction of sediment dynamics and beach-dune morphology thus play an essential role. This expertise typically resides with coastal scientists who have condensed their knowledge in various types of morphological models that serve different purposes and rely on different assumptions, thus have their specific strengths and limitations. This paper identifies morphological information needs for the integrated spatial design of urbanized sandy shores using BwN principles, outlines capabilities of different types of morphological models to support this and identifies current gaps between the two. A clear mismatch arises from the absence of buildings and accompanying human activities in current numerical models simulating morphological developments in beach-dune environments.@en

The multi-dimensionality of BwN calls for the incorporation of ‘designerly ways of knowing and doing’ from other fields involved in this new trans-disciplinary approach. The transition out of a focus on rational design paradigms towards reflective design paradigms such as those employed in the spatial design disciplines may be a first step in this process. By extension, the knowledge base and design methodologies of BwN may be critically expanded by drawing on ways of knowing and doing in spatial design disciplines such as landscape architecture, which elaborates the agency of the term ‘landscape’ as counterpart to the term ‘nature’. Operative perspectives and related methodologies in this discipline such as perception, anamnesis, multi-scalar thinking, and process design resonate with specific themes in the BwN approach such as design of/with natural processes, integration of functions or layers in the territory and the connection of engineering works to human-social contexts. A series of installations realised for the Oerol festival on the island of Terschelling between 2011 and 2018 serve as case studies to elaborate potential transfers and thematic elaborations towards BwN. In these projects inter-disciplinary teams of students, researchers and lecturers developed temporary landscape installations in a coastal landscape setting. Themes emerging from these project include ‘mapping coastal landscapes as complex natures’, ‘mapping as design-generative device’, ‘crowd-mapping’, ‘people-place relationships’, ‘co-creation’, ‘narrating coastal landscapes’, ‘public interaction’ and ‘aesthetic experience’. Specific aspects of these themes relevant to the knowledge base and methodologies of BwN, include integration of sites and their contexts through descriptive and projective mappings, understanding the various spatial and temporal scales of a territory as complex natures, and the integration of collective narratives and aesthetic experiences of coastal infrastructures in the design process, via reflective dialogues.@en

Since the 1990’s the Netherlands has changed its coastal defence system from hard to sediment-based measures, compensating coastal erosion by adding sediment to its sandy shores. In order to keep pace with sea level rise, more nourishments will be needed in the future, including the ‘Building with Nature’ (BwN) technique: large scale nourishments to feed the coastal system for a longer period of time and using natural forces to bring sediment ashore. However, these dynamic nourishments are still in development and put new demands on spatial coastal planning to support dune formation and increase the coastal buffer zone. The objective of this paper is twofold: (1) to discuss how the interactions between the land-shaping processes induced by the nourishments and other coastal functions can be improved as stepping-stones to new design principles for integrated coastal planning enhancing BWN processes, and (2) to provide an overview of initial design principles. Two Dutch cases serve to illustrate the land-shaping processes and the involved design principles. The Walcheren case shows a regional design study for the positioning of BwN (mega) nourishments. This mega-nourishment feeds the narrow dune system as an alternative to the current (more frequent) ways of local beach nourishment. By zoning and staging the nourishment and land use, not only coastal safety, but also other coastal functions, such as recreation, waterfronts and ecology can be improved. The Sand Motor is a prime BwN experiment of mega nourishments in the south of Holland. It is now seven years in progress, featuring an accreting shore, new embryonic dune formation and increased beach recreation. The study shows on a local scale how morphological processes and urban use have evolved and how these processes could be altered and integrated in order to enhance BwN fore dune formation to enlarge the coastal buffer against erosion. The case studies show that the regional design and spatial zoning of nourishment dynamics can help to fine-tune BwN with other coastal functions, such as waterfronts and nature reserves. On the local level dune formation can be improved by adjusting the initial nourishment design, urban and ecological layout to the desired sand transport, using natural landscaping mechanisms as design principle. These will be investigated further in the ShoreScape project.@en

Expected sea-level rise poses an increasing threat to Dutch coastal areas. Continuous human interventions in these areas aim to prevent the lowlands from drowning. This booklet shows the process and results of aeolis-gap the border developed during the elective course Landscape Architecture ON Site, offered by TU Delft MSc Landscape Architecture. As part of the research program related to coastal defence, the group developed an architectural intervention in the dune landscape to accelerate the growth of dunes. The Wadden islands have been barrier islands for the Netherlands for hundreds of years but due to the rising sea level they are under great pressure. Therefore, the Oerol Festival at Terschelling is a great platform to experiment and understand this concept and interweaving it with art. Landscape, art and science come together in this project. The design process is based on experiences of the place, experiments, prototyping results of theoretical and landscape studies, workshops and brainstorm sessions.@en

The land-sea interface is a very attractive location for humans to settle. In the case of low lying, sedimentary coastlines this can be a risky location, as these shorelines are inherently dynamic in nature. Accelerating rates of relative sea level rise will increase coastal erosion, creating world-wide growing demands for coastal protection along urbanized shores. Starting point of this project is that the key to sustainably adapt to this situation is to be found in smart, pro-active sediment management using ‘building-with-nature’ (BwN) approaches, rather than in traditional reactive approaches involving expansion of static, hard coastal defense structures.@en