Experiment and interpretation of geomorphological detection by multi-beam sonar in Huguang-yan Maar Lake

Abstract

The Huguangyan Maar Lake is caused by a volcanic eruption. The original sediments at the bottom of the lake are natural yearbooks for the evolution of the earth’s climate and environment. A multi-beam sonar technique is used to scan the full coverage on the lake surface to get fine samples of echoes form the lake bottom. The information of the bathymetric data of the lake bottom is accurately described and the results of three-dimensional geomorphology imaging are given. The results show that the lake is divided into two parts, east and west, by a north-south underwater volcanic wall, and the maximum depth of water is over 22 meters. We apply a texture feature extraction method based on multi-scale fractal dimension to describe the characteristics of the sediments and roughness. Multi-scale fractal dimensions algorithm is used to extract waveform characteristics of depth samples in different directions. General distribution of sediment at the bottom of the lake is distinguished by the width of multi-scale fractal spectrum. The results obtained can be helpful for the estimation of the physical properties of sediments.