Bedload monitoring with impact plates at Koshibu sediment bypass tunnel

Abstract

Sediment Bypass Tunnels (SBTs) are leading technologies to mitigate reservoir sedimentation that operated in some countries as Japan, Switzerland, and Taiwan. Although their high efficiency are confirmed, the design and maintenance criteria are not well clarified yet. In particular, invert abrasion is one of the severest problems on it and requires high maintenance cost. Measuring bedload transport rate in SBTs is an important step to predict the amount of invert abrasion and bypass efficiency hence improve SBTs management. In this study, we conduct field experiment for bedload measurement with using impact plates at Koshibu SBT, Japan. Grain size and bedload transport rate of the bypassed sediment are described as the function of their output. Finally, the outcomes are validated and applied for the actual flood monitoring.