In the Satsunai River、 many groins have been built as countermeasures of stabilizing the water channels for the purpose of flood control. But recently、 gravel riverbeds are rapidly disappearing because of the said countermeasures. Stabilization of channels might simplify the hydraulic characteristics and deteriorate habitat conditions of water species、 therefore immediate countermeasures are being required. In this study、 I investigate quantity of creature and physics. In addition、 I analyze findings and make the index that used a quantity of no dimension. Furthermore、 I apply this index in an ecosystem evaluation model and evaluate the influence that dam discharge gave to river environment from a respect of habitation environment. |