Bathymetry and Velocity Data from Surveys at Highway Bridges Crossing the Missouri and Mississippi Rivers near St. Louis, Missouri, August 3–10, 2020

These data are high-resolution bathymetry (riverbed elevation) and depth-averaged velocities in comma-delimited table format, generated from hydrographic and velocimetric surveys near highway bridge structures over the Missouri and Mississippi Rivers near St. Louis, Missouri, August 3–10, 2020. Hydrographic data were collected using a high-resolution multibeam echosounder mapping system (MBMS), which consists of a multibeam echosounder (MBES) and an inertial navigation system (INS) mounted on a marine survey vessel. Data were collected as the vessel traversed the river along planned survey lines distributed throughout the reach. Data collection software integrated and stored the depth data from the MBES and the horizontal and vertical position and attitude data of the vessel from the INS in real time. Data processing required computer software to extract bathymetry data from the raw data files and to summarize and map the information. Velocity data for the surveys were collected using an acoustic Doppler current profiler (ADCP) mounted on a survey vessel equipped with a differential global positioning system (DGPS). Data were collected as the vessel traversed the river along seven planned transect lines distributed throughout the reach. Velocity data were processed using the Velocity Mapping Toolbox (Parsons and others, 2013), and smoothed using neighboring nodes. There are 10 zip files for the 10 surveyed sites available for download containing the bathymetric data and depth-averaged velocities. The files follow the format of "site-##_##River_HWY#_2020-08.zip", where "site-##" is the site number from 22 to 35, "##River" is either the Missouri or Mississippi River (as appropriate), and "HWY#" is the highway type and route number. The zip files contain two comma-delimited text files, one with the bathymetry and uncertainty data and one with the depth-averaged velocity data, as well as associated metadata and thumbnails. Reference cited: Parsons, D.R., Jackson, P.R., Czuba, J.A., Engel, F.L., Rhoads, B.L., Oberg, K.A., Best, J.L., Mueller, D.S., Johnson, K.K., and Riley, J.D., 2013, Velocity Mapping Toolbox (VMT) A process and visualization suite for moving-vessel ADCP measurements: Earth Surface Processes and Landforms, v. 38, no. 11, p. 1244-1260. [Also available at https://doi.org/10.1002/esp.3367.]