Abstract
The effect of tsunami run-up on the intake water in a river was estimated. Particularly, the salinity rise of river by tsunami run-up was investigated. The tsunami propagation at the onshore and offshore was calculated. The distribution of salinity density after tsunami disaster in the river was presumedby BOX model in which the tsunami elevation and the velocity taken by tsunami run-up calculation at the river were used. If the salinity density is more 200 ppm, the river water will not be able to take and supply in Japanese standard. The time of intake stop will be greatly influenced by the river flow. When the river flow was slow, the tsunami runs up to the upper reaches on the river, and conveys much salinity flow into the river.
