Sediment Connectivity

Sediment Connectivity: A Framework for Analyzing Coastal Sediment Transport Pathways

Pearson, S.G. (TU Delft Coastal Engineering; Deltares)
van Prooijen, Bram (TU Delft Environmental Fluid Mechanics)
Elias, Edwin P.L. (USGS Pacific Coastal and Marine Science Center)
Vitousek, Sean (USGS Pacific Coastal and Marine Science Center)
Wang, Zhengbing (TU Delft Coastal Engineering; Deltares)

2020

Connectivity provides a framework for analyzing coastal sediment transport pathways, building on conceptual advances in graph theory from other scientific disciplines. Connectivity schematizes sediment pathways as a directed graph (i.e., a set of nodes and links). This study presents a novel application of graph theory and connectivity metrics like modularity and centrality to coastal sediment dynamics, exemplified here using Ameland Inlet in the Netherlands. We divide the study site into geomorphic cells (i.e., nodes) and then quantify sediment transport between these cells (i.e., links) using a numerical model. The system of cells and fluxes between them is then schematized in a network described by an adjacency matrix. Network metrics like link density, asymmetry, and modularity quantify system-wide connectivity. The degree, strength, and centrality of individual nodes identify key locations and pathways throughout the system. For instance, these metrics indicate that under strictly tidal forcing, sand originating near shore predominantly bypasses Ameland Inlet via the inlet channels, whereas sand on the deeper foreshore mainly bypasses the inlet via the outer delta shoals. Connectivity analysis can also inform practical management decisions about where to place sand nourishments, the fate of nourishment sand, or how to monitor locations vulnerable to perturbations. There are still open challenges associated with quantifying connectivity at varying space and time scales and the development of connectivity metrics specific to coastal systems. Nonetheless, connectivity provides a promising technique for predicting the response of our coasts to climate change and the human adaptations it provokes.

coastal sediment transport
graph theory
network analysis
sediment connectivity
sediment transport pathway
tidal inlet

http://resolver.tudelft.nl/uuid:a86d95e0-17c4-4720-bc93-d8f49b14a9c1

https://doi.org/10.1029/2020JF005595

2169-9003

Journal of Geophysical Research: Earth Surface, 125 (10), 1-25

Institutional Repository

journal article

© 2020 S.G. Pearson, Bram van Prooijen, Edwin P.L. Elias, Sean Vitousek, Zhengbing Wang