Sedimentation management of reservoirs is one of crucial issues to realize sustainable development of water resources for the next generations. Recently, sediment-flushing techniques have been applied to Dashidaira dam and Unazuki dam in the Kurobe River, but erosion-deposition process of sediment in reservoirs and its effect on success or failure of flushing operation have been rarely discussed.
This paper studies how to measure actual sediment erosion-deposition process during flushing operations. Firstly, sediment flushing operation in 2004 is overviewed and some typical sediment transport processes in the Unazuki dam are reviewed. Secondary, results of a field measurement with the 3D Laser scanner in the Unazuki dam reservoir are discussed. These results show that 3D Laser scanner can be applicable to measure both water and sediment profiles and those temporal changes.