In this study, we classified in river basins of Chugoku District and created a stream classification map by using GIS analysis and model based clustering. They are classified into 8 types. Then, we clarified basin characteristics of class A river based on above noted classification method. The results of clarification of basin characteristics are effective to express the basin characteristics. Furthermore, we found that faunas of genuine freshwater fish can be potentially explained by basin characteristics. From these, stream classification map can be applied for not only elucidation of water quality but also distribution of freshwater species.
