Summary

Description

Hydrographic survey data were collected from May 22 through June 10, 2015, using an acoustic Doppler current profiler (ADCP) coupled with an RTK-GNSS rover. The collected hydrographic data consisted of three elements—riverbed elevations derived from bathymetry, depth-averaged streamflow velocity, and instantaneous discharge measurements. Hydrographic data were collected as the boat moved across the river at planned cross sections distributed throughout the reach. Data collection software integrated and stored the depth and velocity data from the ADCP and the horizontal and vertical positioning data from the GNSS data in real time. Data processing required computer software to extract bathymetry and velocity data from the raw ADCP and GNSS files and to summarize and map the information. Streamflow was measured to document the streamflow of the river at the time of the survey, and the variation of streamflow around Grande do Pecado Island.