Enhancing dykeland resiliency in a hypertidal estuary

Abstract

Dykelands are low-lying areas created by the reclamation of saltmarshes by the construction of dykes and other infrastructure which are made resilient to the impacts of climate change by the presence of robust foreshore saltmarshes seaward of dyke infrastructure. This study looked at the impact flood and erosion adaptation strategies have had on hypertidal saltmarshes at various spatial and temporal scales in the Bay of Fundy, Canada. While the primary cause of significant foreshore saltmarsh erosion and progradation were a result of natural processes, several features were found to have precipitated significant changes in the position of the foreshore. Borrow pits, which are excavated swaths of saltmarsh excavated from the foreshore for dyke topping material were also studied using an unmanned-aerial-vehicle and structure-from-motion software. Eight out of the 13 borrow pits studied were found to be infilling at a rate which would only reduce dykeland resiliency in the short-to-medium term.