Coastal Foredune Notches – Adoption, Constructed Morphology and Classification

Coastal sand dunes are critical components of coastal zones, delivering essential ecological, 
geomorphic, and societal services. Over at least the last 100 years, climate change and shifting 
land use patterns have driven widespread “dune greening,” characterised by increasing 
vegetation cover and, subsequently, stabilisation of dune systems. While this stabilisation can 
be beneficial for some management objectives, in some locations, it has reduced the 
availability of valuable bare sand and early successional habitats, as well as diminished the 
resilience of dune systems to environmental and climatic changes. To address these 
challenges, constructed foredune notches have been increasingly implemented as coastal 
management interventions. These notches aim to restore dune dynamism, promote sediment 
movement, and (re)create habitats by providing a pathway for aeolian sediment transport from 
beaches into the middle and back dune areas. 
Despite their growing application, research on the design, functionality, and long-term impacts 
of foredune notches remains limited, particularly at a global scale. In this study, we 
systematically identified and analysed 133 foredune notches across four countries using aerial 
imagery to assess variations in their constructed morphology. Our findings reveal significant 
regional differences in notch dimensions: notches in France and New Zealand tend to be 
smaller and more uniform in design, while those in the United Kingdom and the Netherlands 
exhibit larger and more variable morphological characteristics. These regional variations, 
especially notable in the Netherlands, are underexplored in current literature, leaving important 
gaps in understanding how initial design influences the performance and persistence of these 
features.
To complement this analysis of the constructed morphology of foredune notches, this study 
also investigates how the identified differences in constructed morphology affect notch 
evolution over time, using a time series of aerial imagery from selected sites in Europe. Initial 
results suggest that constructed morphology significantly impacts the spatial dynamics and 
longevity of foredune notches, with important implications for achieving ecological and 
geomorphic management objectives.
To improve the consistency and transferability of research and management practices, this 
study proposes a standardised classification framework for foredune notches based on key 
morphological characteristics. The proposed framework provides a systematic approach to 
describing and comparing notches across sites and regions, allowing existing and future 
research to be better applied across notches and sites, therefore hopefully enabling 
researchers and practitioners to design notches with a better understanding of their likely long-term impact.