An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data

Snellen, M.; Eleftherakis, S.; Amiri-Simkooei, A.; Koomans, R.L.; Simons, D.G.

doi:doi:10.1121/1.4812858

An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data

Title

An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data

Author

Snellen, M.
Eleftherakis, S.
Amiri-Simkooei, A.
Koomans, R.L.
Simons, D.G.

Faculty

Aerospace Engineering

Department

Control & Operations

Date

2013-08-01

Abstract

This contribution presents sediment classification results derived from different sources of data collected at the Dordtse Kil river, the Netherlands. The first source is a multi-beam echo-sounder (MBES). The second source is measurements taken with a gamma-ray scintillation detector, i.e., the Multi-Element Detection System for Underwater Sediment Activity (Medusa), towed over the sediments and measuring sediment natural radioactivity. Two analysis methods are employed for sediment classification based on the MBES data. The first is a Bayesian estimation method that uses the average backscatter data per beam and, therefore, is independent of the quality of the MBES calibration. The second is a model-based method that matches the measured backscatter curves to theoretical curves, predicted by a physics-based model. Medusa provides estimates for the concentrations of potassium, uranium, thorium, and cesium, known to be indicative for sediment properties, viz. mean grain size, silt content, and the presence of organic matter. In addition, a hydrophone attached to the Medusa system provides information regarding the sediment roughness. This paper presents an inter-comparison between the sediment classification results using the above-mentioned methods. It is shown that although originating from completely different sources, the MBES and Medusa provide similar information, revealing the same sediment distribution.

Subject

backscatter
Bayes methods
geochemistry
geophysical techniques
hydrophones
natural radioactivity hazards
rivers
scintillation counters
sediments
soil pollution