2012 年 5 巻 1 号 p. 70-79
In the processes of designing reservoirs, planning river channels and managing downstream river environments, it is very important to clarify the mechanism of transport for suspended sediment in basins and to quantitatively evaluate the amount of sediment discharge. In this study, year-round monitoring and calibration were conducted using high-range turbidimeters at five observation points in the Mu and Saru river basins, and a practical estimation equation for the evaluation of suspended sediment (SS) concentration (mg/L) as determined from the measured turbidity value (ppm) at each point was proposed. The estimation equation is expressed as a simple linear function of discharge Q, and is able to accurately reproduce water sampling results and the turbidimeter measurements taken at the observation points. The characteristics of sediment discharge in the Mu and Saru river basins were also examined based on SS concentration values obtained from the year-round monitoring in 2010 using the simple estimation equation proposed. The study results revealed that the sediment discharge process and amount varied among the measurement points in the two basins, and that there were clear seasonal variations among the snowmelt, summer and other seasons in both basins.
