Sandy solutions for saving our shores from sea level rise: a Dutch perspective
In an era of rising seas and other challenges posed by climate change, coastal regions like the Netherlands face ever graver threats. In response to chronic erosion and catastrophic floods throughout their history, the Dutch armoured their coast with dikes and dams. However, their latest strategy favours building with nature instead of fighting against it, by strategically placing sand ("nourishing") to reinforce beaches and dunes. This approach could mitigate the threat of coastal erosion and sea level rise while limiting ecological impacts. However, we don't yet know enough about the pathways that this nourished sand will take - where does all the sand go? To tackle this challenge, we developed new tools and techniques for analyzing a combination of field measurements and numerical models. These include a method for analyzing the stratigraphy and mapping the evolution of ebb-tidal deltas, a new technique to estimate the amount of sand or mud in the water, and glow-in-the-dark, magnetic sand grains that we can follow around. We also came up with a new approach to quantify and think about coastal sediment pathways via the sediment connectivity framework, and developed a sand-tracking model to visualize and predict these pathways efficiently. We developed these approaches for a site on the Dutch coast, but the techniques shown here are useful in a wide range of coastal settings beyond the Netherlands, including Canada. By managing our coastal sediment more effectively, we will set the stage for a more sustainable future, in spite of the challenges that lie ahead.
Stuart Pearson is a coastal engineering PhD candidate/soon-to-be postdoctoral researcher at Delft University of Technology (TU Delft) and consultant/researcher at Deltares, both located in Delft, the Netherlands. He received his MSc in Coastal and Marine Engineering & Management jointly from TU Delft, the University of Southampton (UK), and the Norwegian University of Science & Technology (NTNU). Originally hailing from Canada, he grew up on the shores of the Great Lakes and completed his BASc in Civil Engineering at the University of Waterloo. He also worked for several years as a coastal engineering consultant at Baird & Associates in Oakville, Ontario. Today his research focuses on understanding how waves and tides move sand around on our coasts, so that we can better manage flooding and erosion in the face of sea level rise and climate change.