A Study on Role of Fluctuation in River Discharge in Forming River Environment

Abstract

There are a number of clear reasons for researching the fluctuations in river discharge. Based on nationwide surveys, it is reported that because the seasonal fluctuations in stream-flow in some rivers have decreased, the bottom quality of the riverbeds has worsened and is exerting bad effects on the fish and other wildlife. In this paper, the purpose is to conduct research into the role of fluctuations in river discharge in maintaining and forming the river environment. First, we review the actual condition and the knowledge gained from existing research results concerning the influence exerted on the river's ecosystem by fluctuations in river discharge. Next, we present the concept of macro-habitat. We set up temporary working hypotheses concerning the influence of fluctuations in river discharge on the river environment and suggest an evaluation index for verifying them.