Authors: W. R. Hoyle and S.J. Rigbey
HydroVision 2008
Abstract
Underwater sonar techniques are regularly used to determine the bathymetry of reservoirs and channels. Regular techniques are effective in establishing snapshots of the bottom contours, however they do not necessarily provide for accurate correlations between consecutive surveys. Recently detailed high-resolution sonar profiling methods have been developed by Hatch that can provide repeatable bathymetric surveys to “centimeter accuracy”. Our system incorporates an underwater pitch/roll/yaw sensor, which is critical to track minor deflections of the sonar head while a total station survey records its exact position. Detailed sonar profiling has proven to be invaluable in the detection and monitoring of sinkholes in reservoirs and on the upstream slopes of earth embankments. It has been also been specified for baseline purposes at a newly commissioned dam. The system has been successfully applied to the survey of plunge pool scour areas, including detailed definition of overhangs. It has also been used for rapid bank-tobank profiling of tailrace channels and rivers.
