Description |
This data release provides a series of four bathymetric change grids generated from historical bathymetric surveys collected in central San Francisco Bay, CA from the 1855 to 1979. The National Ocean Service (NOS) and its predecessor, the United States Coast and Geodetic Survey, collected hydrographic surveys in 1855, 1895, 1920, 1947, and 1979. Surface modeling software was used to generate bathymetric DEMs of each of these surveys. The bathymetric DEMs were then adjusted to account for gridding interpolation bias and changes in sea level through time. The adjusted DEMs for consecutive surveys were then differenced to reveal the amount of sediment erosion and deposition and changes from human activities (e.g., dredging, sand mining, and sediment placement) that occurred through time. These bathymetric change grids are provided here in GeoTIFF format with a horizontal resolution of 25 meters and can be used to quantify net sediment volume change and rates of change throughout the bay. [More]
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