Urban dunes

Towards BwN design principles for dune formation along urbanized shores

Authors

Keywords:

Building with Nature, nourishment, dune formation, urban coast, design principles

Abstract

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.

Author Biographies

Janneke van Bergen, Delft university of Technology

Janneke van Bergen is a landscape architect and PhD researcher at the TU Delft. Over the past decade she worked in the field of water and infrastructure, including Room for the River, the National Coastal Delta Program and Studio Coastal Quality. She currently works for the ShoreScape research, funded by NWO, to investigate Building with Nature and coastal design.

Jan Mulder, University of Twente

Jan P. M. Mulder graduated in Physical Geography and did a PhD in Forest Hydrology. After working as hydrologist at TNO for two years, since 1986 he has been active in the field of Coastal Morphology and - Management. Initially at Rijkswaterstaat, from 2008 at Deltares and after retirement in 2013, as a private consultant. In the framework of the Netherlands Centre of Coastal Research-NCK, he has been a guest researcher at Twente University since 2004 until today.

Steffen Nijhuis, Delft University of Technology

Steffen Nijhuis, PhD, is initiator of this publication, Head of Landscape Architecture Research and Associate Professor Landscape Architecture at the Faculty of Architecture and the Built Environment, Delft University of Technology (The Netherlands). www.steffennijhuis.nl

Daan Poppema, University of Twente

Daan Poppema is a PhD Candidate at the University of Twente, examining how buildings at the beach-dune interface affect the morphology of the beach-dune system. In his work he combines field work and computer modelling. He has a background in civil engineering, with a master in Water Engineering and Management from the University of Twente.

Kathelijne Wijnberg, University of Twente

Prof dr Kathelijne Wijnberg has a background in coastal geomorphology (PhD in 1995, Utrecht University). Through positions held at Oregon State University, Delft Hydraulics and University of Twente, she developed a keen interest in problems at the interface of coastal systems understanding and societal needs. Since 2018 she holds a chair in Coastal Systems and Nature-Based Engineering.

Mieke Kuschnerus, Delft University of Technology

Mieke Kuschnerus has a Masters degree in Mathematics from Technical University Berlin. After working in the Earth Observation department of the European Space Agency she joined the Geoscience and Remote Sensing Department at Delft University of Technology as a PhD in 2019. Her work is focusing on the detection, clustering and characterization of coastal variability using permanent laser scanner data.

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Published

2021-02-18