Abstract
Many of the dams and reservoirs in Japan have been operated for more than thirty years and some of them face sedimentation problems. In addition research and investigation of climate change is ongoing and its impact has been clarified recently. Therefore the authors try to predict future reservoir sedimentation considering impact of climate change by use of a sediment runoff model developed by Egashira and Matsuki. The authors consider that their sediment runoff model is convenient because a topographic model of the dam’s basin for numerical analysis is relatively easy to provide. However, the model does not have a sediment supply process from mountain slopes to river channels. This is an issue and applicability of the model is considered to be limited. In this paper the authors carry out correlation analysis between water inflow to reservoirs and reservoir sedimentation for several dams and analyze applicability of the model from the viewpoint of relationship between correlation coefficient and characteristics of the dam’s basin. As a result, the authors reach a conclusion that large specific sedimentation rate and gentle river bed slope near the reservoir entrance are important characteristics for applicability of the model. In the end the authors carry out simulation analysis of reservoir sedimentation against one of the dams and confirm acceleration of future reservoir sedimentation due to the impacts of climate change.
