Connectivity Between Sediment Storage in Dam Reservoir and Coastal Erosion: Implications Through Zonal Mappings of Monitoring Data

Yokoo, Y. and Udo, K., 2016. Connectivity between sediment storage in dam reservoir and coastal erosion: implication through zonal mapping of monitoring data. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 725–729. Coconut Creek (Florida), ISSN 0749-0208. In the present study, we investigated the relationship between sediment storage in dam reservoirs and coastal erosion covering 71 coastal zones in Japan. Consequently, we found a weak but significant positive correlation between sediment storage in dam reservoirs and coastal erosion. The weakness of the correlation here indicates that sediment storage in dam reservoirs is not the primary cause of coastal erosion. In addition, we developed a simple methodology for estimating sediment inflow into a dam reservoir based on hourly turbidity and water inflow measures for the selected Miharu dam reservoir. Using this estimation, we explored the current relationship with precipitation intensity and this relationship can be used for climate change impact and adaptation studies. Our provisional investigation into the Miharu dam watershed showed that the hysteresis effect in the relationship is negligible, although further studies are necessary to validate our claim.