Abstract
An elaborated model for the blue coloration of Aoike Pond, Aomori Prefecture, was proposed. In the elaborated model, water’s density fluctuation scattering coefficients and a volume scattering function were referred from literatures, and calculation methods for solid angles were refined. In addition, formulas for light intensities produced by irregular reflection at lake bottom and by density fluctuation scattering in lake water were described on the bases of light flux. Image analyses enabled us to determine a scaling factor that connected the observed RGB values in the images of Aoike Pond to the theoretically predicted ones, and a sensitivity factor of the digital camera was separated from the scaling factor. As a result, there were highly linear relationships between the observed and theoretically predicted RGB values, and thus the observed colorations were reproduced fairly well in wide areas on the images. Hence, the elaborated model was capable of quantitatively describing the blue colorations with high validation.
