Analyzing Bedforms Mapped Using Multibeam Sonar to Determine Regional Bedload Sediment Transport Patterns in the San Francisco Bay Coastal System

The length, height, depth and asymmetry of 3386 individual bedforms were measured from high-resolution grids derived from a series of multibeam surveys conducted in the San Francisco Bay coastal system. Powerful tidal currents that can exceed 2.5 ms-1 generate bedforms that measure up to 317 m in wavelength, and up to 10 m in height. Detailed analysis of bedform shape indicates that there are regions where ebb-directed or flood-directed bedload transport is predominant, revealing important sediment transport pathways. The increased mapping resolution of multibeam technology over the past decade allows for the gathering of highly detailed, quantitative information regarding bedforms and thus advances understanding of coastal sediment transport processes and provides valuable information to coastal managers for more efficient sediment resource management.