|We have studied a method to understand the continuous temporal and spatial distribution of turbidity
based on the acoustic backscatter obtained by ADCP observation in lakes and rivers. We examined the
correlation of turbidity and backscatter intensity by towing observation and fixed-point observation in
rivers and lakes. First, we showed improvement of accuracy in high-turbidity estimation due to use sonar
equation by considering the attenuation of backscattering strength. Such as emitting depend on distance
from sencer, the absorption of sound by water and the absorption of sound according to the turbidity.
Next, we confirmed vertical distribution of turbidity estimation in the dam lake. We ware reproduced
turbidity in high-turbidity layer over some hundred ppm at medium-to-lower depth of center lake, but in
part of river inflow and surface of center lake where is low-turbidity below 100 ppm, the accuracy of
turbidity reproduction was lower than high-turbidity case.