Nearshore sediment transport as influenced by changing sea ice, north shore of Prince Edward Island, Canada

Abstract

This study considers the influence of changing sea ice on nearshore sediment transport in the central north shore of Prince Edward Island, Southern Gulf of St. Lawrence. It is widely accepted that changing climate is causing sea ice to decrease in the region. Sea ice attenuates wave energy thereby reducing sediment transport. The Delft3D hydrodynamic model is used to simulate waves, currents, and sediment transport in seven sea ice concentration scenarios which can be differentiated into four classes: open water (<10%), low ice (10% to 35%), moderate ice (36% to 60%), and high ice (>61%). If ice concentration decreases from high to moderate, sediment transport is expected to increase 20%. Similarly, if ice concentration decreases from moderate to low sediment transport is expected to increase a further 21%. If ice concentration decreases from low to open water conditions sediment transport is expected to abruptly increase a further 60%, indicating nearly 100% increase in nearshore sediment transport between high ice concentrations and open water conditions. Linear and power-law fits of sediment transport and sea ice concentration intersect at an ice concentration of 30% indicating this value may be a useful threshold in planning for increased coastal erosion and developing appropriate adaptation strategies, in particular, adapting to increased sediment transport near tidal inlets and navigation channels.

Landscape and Seascape Responses to Canada’s Changing Climate

“…Coastline armouring is a protective role that is sensitive to climate change. Simulations of the effects of sea ice concentration variations on nearshore sediment transport on the North Shore of Prince Edward Island reveal a nearly 100% increase in shoreface sediment transport under open water relative to conditions of high winter ice concentration seaward of the nearshore fast ice (Manson 2022). Decreases in sea-ice concentrations are projected for the Gulf of St. Lawrence and the study results, which imply increased exposure and sensitivity to winter storms, can inform the development of adaptation strategies to deal with increased sediment transport near tidal inlets and navigation channels, in addition to the well-recognized acceleration of coastal erosion.…”

Impact of changes in sea ice cover on the wave climate of semi-enclosed, seasonally ice-covered water bodies at temperate latitudes: a case study in the Gulf of Riga

“…All these water bodies are impacted by climate change that generally leads to a shortening of the ice season and alternations to ice properties (Ruest et al 2016;Huang et al 2021). The loss of ice in such water bodies naturally leads to changes in wave properties: an increase in the significant wave height (Wang et al 2018) and a substantial intensification of nearshore sediment transport (Manson 2022).…”