ISSUES OF RESERVOIR SEDIMENTATION AT YAHAGI DAM AND DISCUSSION ON COUNTERMEASURE

Abstract

Dams in Japan contribute the sustainability of human activities which is accomplished by flood control, water resources arrangement and ecosystem conservation in river basin. However, construction of new dams is no longer feasible and the maintenance techniques of dam-and-reservoirs are necessary to be developed. Particularly the problem of sedimentation is serious, which threatens the sustainability of dam-and-reservoir functions. In this study, the Yahagi dam is focused, and the recent state of sedimentation and the problems caused by it are investigated. And the feasibility and effect of the countermeasures are studied by dividing into short, intermediate and long-term ones through hydraulic investigation.