Coastal mapping and modelling of Tuktoyaktuk Harbour, Western Arctic, Canada

Abstract:

Climate models suggest that sea ice in the Arctic is expected to decrease and that the frequency of storms bringing high waves and storm surges is expected to increase. Reduced sea ice, higher waves, and higher storm surge water levels have implications for coastal infrastructure, nearshore sediment transport, and rates of coastal change. Tuktoyaktuk is an important shipping terminal servicing the petroleum industry and Inuvialuit communities in the western Canadian Arctic. The hydrodynamic model Delft3D is used to model sediment transport in Tuktoyaktuk Harbour and the approaches. For nearshore applications, Delft3D works best with a seamless coastal digital elevation model (DEM). A DEM was constructed from a variety of sources. Terrestrial LiDAR (Light Detection And Ranging) uses an infrared laser to construct a detailed elevation model of the terrestrial coastal zone. Multibeam bathymetry uses arrays of acoustic signals to collect detailed of the subaqueous coastal zone. Bathymetry data, and charts from the Canadian Hydrographic Service supplement the offshore bathymetry. The shoreline is derived from CanCoast, a nationally consistent geospatial database of Canada's marine coasts. The Coastal Information System (CIS) supplements CanCoast and describes coastal geomorphology in local areas. With these data, Delft3D delivered wave, current, and sediment transport data in a common reference frame. When compared to measurements, the model successfully simulates waves and currents. Output from Delft3D was mapped into a Geographic Information System, and combined with other data to help an Arctic community and industries adapt to potential climate-related hazards .