A decade of beach-dune morphodynamics research at Greenwich Dunes, PEI, Canada.

This paper summarizes a decade of collaborative research on beach-dune morphodynamics at Greenwich Dunes, PEI, Canada. Advances made via various evolving techniques to quantify process-response relations between airflow, sand transport, surface properties and beach-dune morphology are reviewed. Efforts to characterize micro-scale aeolian sand transport with piezoelectric sensors, laser particle counters, moisture probes and digital photography have improved our understanding of temporal and spatial variability in the transport process as controlled natural factors (surface moisture, fetch, vegetation). Meso-scale morphodynamics are examined by event-based experiments with ultrasonic anemometry to explore relations between topographically forced airflow, near-surface stress and sand transport over foredunes. This work has enhanced knowledge on flow-form interactions over complex terrain that control sand transport pathways and foredune morphodynamics. Finally, macro-scale evolution of the system is investigated by seasonal to decadal sedimentation patterns and morphological changes from a network of erosion pins, volumetric change plots, cross-shore profiles and digital photogrammetry of historical aerial photographs. This research helps improve application of event-based experimental datasets or parameterized models of sand transport to understand longer-term landscape evolution by characterizing morphodynamic responses to seasonal/annual processes and broader geomorphic controls (e.g., sea level rise, storms). However, until seasonal variations in sand transport and beach-dune morphology can be parameterized, prediction of sand supply to the foredune will remain limited. Relatively infrequent, high magnitude storm surges also significantly influence system trajectories and the foredune is responding to relative sea-level rise consistent with the conceptual model of Davidson-Arnott (2005).