CHARACTERISTICS OF FINE SEDIMENT DISCHARGE DURING SEDIMENT FLUSHING OF UNAZUKI DAM

In the Kurobe River, coordinated sediment flushing and sediment sluicing of Dashidaira and Unazuki dams have been executed since 2001. From the view point of the comprehensive sediment management in the sediment routing system, monitoring of quantity and quality of sediment transport during these events in rivers and reservoirs is very important. This paper shows the results of field data obtained during sediment flushing and sluicing operation of Unazuki dam in June-July, 2005. Suspended sediment concentration measured by the manual sampling and SMDP ( Suspended Sediment Concentration Measuring System with Differential Pressure Transmitter), turbidity measured by a high rage turbidimeter and grain size distribution are discussed. Cleary, based on the progress of sedimentation of Unazuki reservoir, sediment discharge characteristics of Unazuki dam have been changed year by year.