Seismic reflection profiling on rivers and reservoirs

Information about the internal structure of the upper sediment layers is of great importance both for current monitoring measures and for prognostic process modeling of sediment transport. Seismic methods offer a sophisticated approach to determine this basic data, provided that object properties such as water depth, current, etc. are suitable. The quality of the results, like penetration depth and resolution of the sediment structure depends on the system-specific parameters and the sediment quality. This article deals with the use of high-resolution seismic systems in order to detect sediment build-up in water bodies with fundamentally different soil structures. Parametric sub-bottom profilers (SBP) from Innomar (Germany) and Kongsberg Maritime (Norway) were used to carry out extensive sediment echo sounding in the sedimentation basin of Rottau (silt) and the river Danube (gravel). Comparing the evaluation of sediment cores to the resulting echograms indicates a great potential of SBP for fine sediment soils, but also shows limitations where coarser material occurs. Some special application options for soils with a thin top layer of gravel are available though, thus initiating further investigations with SBPs and alternative seismic methods for this type of sediments.