Influence of changes of deforestation area and reforestation area on sediment yield

Abstract

Forest management of Japan has been depressed in recent years. It is due to low-level stumpage price, low profit in forestry production, and decreasing number of forestry workers, who has been aged. And depressed forest management frequently causes serious devastation of hill slopes and torrents.
This study cleared an influence of annual varietion of deforestation area and reforestation area on sedimentation of Miyakawa-dam, Mie prefecture. Using these results, sediment yield predicting model considering annual precipitation and forest practice conditions was constructed. And this sedimentation model was applied to Miyakawa-dam basin. As the result of this simulation, comparison of the observed and calculated sedimentation showed that this simulation model was adequate for the predicting the sediment yield in Miyakawa-dam basin.