Drawing lines in the sand – the evolution of Dutch coastal policy
Jill Slinger
1, Heleen Vreugdenhil
2, Leon Hermans
1, Scott Cunningham
1,
Ankie Bruens
3, Jan Mulder
3& Marja Menke
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Delft University of Technology, Jaffalaan 5, 2628 LX Delft, Netherlands
j.h.slinger@tudelft.nl
Introduction
The Dutch coast has long been at threat from sea level rise and coastal storms. With predicted increases in sea levels, and the enhanced severity and frequency of storms associated with climate change, this threat will persist and increase. We explore the evolution of policy by examining how the scale preferences of the actors influenced the conceptual basis of, and choices for, large scale sand nourishment from 1990 onwards. We develop an integrated scale hierarchy for sandy coasts (Figure 1) and examine the alignment of the concept underpinning the coastal policy of 1990 with the sand nourishment choices made over the next twenty years. We identify discrepancies between the spirit of the policy and its implementation in practice.
Figure 1. Subjective scale preferences portrayed on an Integrated Scale Hierarchy for Sandy Coasts (see Vreugdenhil et al 2010). The position of the policy protagonist differs from the current implementation scale as indicated by the star.
Reference
Vreugdenhil HIS et al. (2010). The influence of scale preferences on the design of a water innovation: A case in Dutch river management. Environmental Management (2010) 46:29–43.
Geomorphological concept underpins policy
Coastline retreat can be halted by utilizing natural geomorphological processes. In 1990 the choice is made to defend the Dutch coast using ‘soft’ interventions such as sand nourishment rather than hard constructions (groynes, dikes) if the predicted coastline position (TCL) lies behind the 1990 base coastline (BCL), that is when the policy criterion TCL-BCL < 0.
Results
A three-year cycle can be distinguished in decision making in North Holland (Figure 3). The momentary state of the coastline (MCL) drives interventions. The policy criterion of TCL-BCL co-determines nourishment interventions from 1996 onwards. There are less nourishments interventions after 2000, owing to the new method of underwater nourishment at the shoreface.
The policy criterion (TCL-BCL) never forms the determining factor for nourishments in the nature conservation area. Instead, the timing and frequency of nourishments in the nature conservation area are determined by the needs of the nearby coastal resort.
Figure 3. Decision making on policy implementation at Egmond on Sea in North Holland. Arrows connect the criterion used to the resulting sand nourishment or BCL intervention. Question marks denote uncertainty regarding the criterion used in decision making.
Conclusion
• Subjective scale preferences of local and regional actors combine to make the implementation of the policy occur at a scale lower than that appropriate to the geomorphological concept underpinning the policy.
• Regional differences in policy implementation arise.
• With the introduction of shoreface nourishments economic and geomorphological interests combine and interventions are scaled up.
Method
Data collection occurred through interviews, extensive policy document review and workshops including a validation workshop on 27 september 2011. In-depth analysis of data transects from North Holland from 1960 to 2007 (Figure 2) were used to compare policy prescriptions and decision making in practice.
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photograph courtesy of www.rws.nl
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Figure 2. Database of measured transects along the Dutch coast used in the analysis
