2019 Volume 75 Issue 2 Pages I_725-I_730
A new method by the concept of entropy has been used to classify sediment color distribution. We objectively characterized the distribution profile and clarified the relationship between the geology and sediment characteristics. Sediment colors were defined by L*a*b* instead of RGB, and of the following four indexes, lightness, hue, saturation and chromaticity, lightness was the optimal index. In order to determine the optimal number of groups, a C-H criterion, Rs statistic and the skewness of the third moment on sediment color distribution were used. The sediment colors could be divided into 7 groups. Kagoshima Pref. has geology of the Shirasu plateaus, but the sediment color could be grouped by white minerals such as quartz and feldspar contained in granite and pyrophorite and colored minerals such magnetite contained in mafic volcanic rock, and therefore, they can be related to geology. In addition, it could be possible to make sediment transport path clear by focusing on a specific mineral such as olives.
