Coastal erosion threatens flood safety and other uses of beaches and dunes globally. In the Netherlands a coastline maintenance policy was implemented in the 1990's to address the negative effects of erosion, with sand nourishments as the primary means. In this study, the cumulative effects of these nourishments are evaluated against the strategic goal of sustainable preservation of the uses and values of the coast. This research aims to inform national and international policy makers, practitioners, and scientist about the possible long-term effects of coastal management with structural sand nourishments. Coastal indicators were analysed to quantify the morphological evolution of the coast before and since coastline maintenance. It is observed that regular nourishments serve to halt structural coastline retreat. The coastline built out, on average, which was necessary to achieve maintenance of the most erosive areas. Additionally, strong dune growth is observed since the start of coastline maintenance, thanks to wind-driven transport of nourished sand and more dynamic dune management. Nourishments thus contribute positively to flood safety, although flood safety is not an automatic benefit of coastline maintenance. Space for recreation and nature is maintained or improved: the dry beach width was unaffected, and dune areas have grown. Further, it is reported that the impact of nourishments on the coastal ecosystem is local and temporary, leading to the inference that uses and values of the coast are being maintained sustainably through regular nourishments. Overall, the approach of coastline maintenance with regular pro-active nourishments has thus proven to be successful.

Coastal areas world wide are highly dynamic areas, subject to continuous deformation processes. Both natural and anthropogenic processes constantly cause changes at various spatial scales. Sandy beaches in the Netherlands fall under a regulation, according to which moving sand is permitted, if the volume change remains below a certain threshold. The threshold holds for volume changes within a cross section of 1 m width of the beach. The enforcement of this rule is currently labor intensive, because monitoring generally happens only on a yearly basis, or incidental and non-quantitative. Improved observation capabilities with remote sensing are advancing the supporting technology for this kind of regulations. Permanent laser scanning is a potential tool for monitoring and quantifying volume changes of a section of the beach. We develop and implement methodology to extract time series of volume change with respect to a reference date of 01-01-2020 covering January 2020 until the end of April 2020. The method is applied on point cloud data from a permanent laser scanner on the coast of Noordwijk, The Netherlands. We analyse the time series for incidents, where the threshold in volume change is passed, and find all shortest intervals during which the threshold is passed. Then we analyse potential underlying cause in order to support not only enforcement, but also evaluation of the current regulation. This will ultimately help to work towards a better understanding of the influence of small scale human activities on coastal development.