Characterization of bottom sediments in lakes using hydroacoustic methods and comparison with laboratory measurements

The acoustical properties of bottom sediments in two lakes were shown to be strongly correlated with clay content, organic C and total N concentrations, and other important sediment properties. The fractal dimension of the bottom echo was more strongly correlated with sediment physical and chemical properties than energy-based measures. The fractal dimension was also related to rates of PO4-P and NH4-N release from intact sediment cores and sediment oxygen demand. Measurements made at 430-kHz were more sensitive to differences in sediment properties than 201- or 38-kHz. Hydroacoustic measurements allow rapid assessment of properties important in lake restoration and water resource management.

► Sediment properties strongly correlated with acoustical properties of bottom sediment.
► Fractal dimension of bottom echo most strongly correlated with sediment properties.
► Fractal dimension also related to rate of nutrient release and sediment oxygen demand.
► Somewhat stronger correlations found at 430-kHz relative to 201- and 38-kHz.
► Hydroacoustic methods useful for habitat assessment, lake management and restoration.