Abstract
When material dredged from a dam reservoir is used for beach nourishment, such an operation is often feared among fishermen, because fine components contained in the material are considered to damage the fishery in coastal sea. To study this issue from the scientific point of view, the characteristics of the materials dredged from the reservoir and those sampled from sandy beach were compared, taking Takataki Dam in the Yoro River basin and Kujukuri Beach as the study areas. Materials were sampled from many points in Takataki Dam reservoir and on Kujukuri Beach, and sieve analysis was carried out. As a result, it was found that the silt content in the material dredged from Takataki Dam was as high as 18.4%, whereas that of the beach in Katagai fishing port was 3.9% at maximum; the content of silty material was five times greater than that on the beach.
