Bathymetric change analysis in San Francisco Bay, California, from 1971 to 2020

This data release supersedes version 1.0, published in April 2023 at https://doi.org/10.5066/P9Y5PEV0. Versioning details are documented in the accompanying SFBay_BathyChange_VersionHistory.txt file. 
This data release provides bathymetric change grids of four geographic areas of San Francisco Bay, California, comparing digital elevation models (DEMs) created from bathymetric data collected in the 1970s and 1980s with DEMs created from bathymetric data collected in the 2010s and 2020. These types of change analyses can provide information on the quantities and patterns of sediment erosion and deposition in San Francisco Bay over the 9 to 47 years between surveys, and they reveal that the bay floor lost about 20 million cubic meters of sediment between the intervening time period. Results from this study can be used to assess how San Francisco Bay has responded to changes in the system such as sea-level rise and variation in sediment supply from the Sacramento-San Joaquin Delta and local tributaries, and supports the creation of a new, system-wide sediment budget. These bathymetric change grids can also provide data to ecosystem managers about the quantities and patterns of sediment volume change in San Francisco Bay to assist in decision-making for a variety of sediment-related issues, including restoration of tidal marshes, exposure of legacy contaminated sediment, and strategies for the beneficial use of dredged sediment.