|Résumé||(disponible en anglais seulement)|
The Canadian Hydrographic Service in collaboration with the Canadian Geodetic Survey recently completed a set of tidal water level models as part of the
Continuous Vertical Datum for Canadian Waters (CVDCW) project. The CVDCW connects tidal water level datums (high and low water levels, chart datum, etc.) to a national geodetic reference frame for all Canadian tidal waters. In the past, this was
possible only at tide stations which had been surveyed with GPS or by leveling. The CVDCW captures the spatial variability of tidal water levels between stations and offshore by integrating ocean models, tide gauge records, GPS observations, sea
level trends, satellite altimetry, and a geoid model. In addition to its use for hydrography, the CVDCW will allow easier integration of hydrographic and terrestrial data by linking them through a common reference frame. Thus it can provide a
baseline for storm surge and sea level rise estimates, help delineate flooding thresholds and intertidal zones, and aid with practical issues such as sovereignty and the definition of coastlines. Our presentation will begin with a brief overview of
the CVDCW. We will then show how the CVDCW improves over traditional multibeam survey reduction methods, using examples from recent surveys in the Arctic where the tidal regime is poorly sampled. Finally, we will present preliminary results of a
project to combine CVDCW surfaces with LiDAR data from Victoria Straight, which define a set of shorelines representing high and low water lines.