Sediment Connectivity: A Framework for Analyzing Coastal Sediment
Transport Pathways
Abstract
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). Existing
techniques in graph theory and network analysis provide a low barrier to
entry for using connectivity to quantify complex coastal systems,
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 are 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 through the system. These metrics allow us to
address fundamental questions about sediment bypassing of Ameland Inlet
and the optimal placement of sand nourishments. Connectivity thus
provides a novel and valuable technique for predicting the response of
our coasts to climate change and the human adaptations it provokes.