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Topobathymetric Model of the Strait of Juan de Fuca, 1891 to 2016

July 9, 2021

To support the modeling of storm-induced flooding, the U.S. Geological Survey (USGS) Coastal National Elevation Database (CoNED) Applications Project has created an integrated 1-meter topobathymetric digital elevation model (TBDEM) for the Strait of Juan de Fuca, which is located at the outlet of the Salish Sea. The international boundary between Canada and the northwestern part of the United States bisects the strait. High-resolution coastal topobathymetric data is required to identify flooding, storms, and sea-level rise inundation hazard zones and other earth science applications, such as the development of sediment transport and storm surge models. The new TBDEM consists of the best available multi-source topographic and bathymetric elevation data for the Strait of Juan de Fuca including neighboring islands, canals, and inlets. The Strait of Juan de Fuca TBDEM integrates 11 different data sources including topographic and bathymetric data, such as lidar point clouds and multi-beam acoustic surveys obtained from USGS, the National Oceanic and Atmospheric Administration, the U.S. Army Corps of Engineers, the Puget Sound Lidar Consortium, and the Washington Department of Natural Resources. The topographic and bathymetric surveys were sorted and prioritized based on survey date, accuracy, spatial distribution, and point density to develop a model based on the best available elevation and bathymetric data. Because bathymetric data are typically referenced to tidal datums, such as Mean High Water or Mean Low Water, all tidally-referenced heights were transformed into orthometric heights based on the GEOID12B datum, which is normally used for mapping elevation on land using the North American Vertical Datum of 1988. The spatial horizontal resolution is 1-meter with the general location ranging from Victoria, British Columbia in the north to Port Angeles, Washington in the south and extending to a depth of 365 meters. The overall temporal range of the input topography and bathymetry is 1891 to 2016. The topography surveys are from 2005-2016. The bathymetry surveys were acquired between 1891 and 2015.