High Resolution Numerical Model for Salinity Transport in Rivers During a Tsunami Attack

抄録

In the event of a tsunami, saltwater flows into rivers and water purification plants must stop taking water from rivers to prevent entry of saline water into the plant owing to potential damage to machinery and contamination of the system. This leads to interruption of water supply during disaster. In this study, a salinity transport simulation model that can carry out a three-dimensional salinity behavior analysis in a specific area and a horizontal two-dimensional tsunami propagation analysis simultaneously was developed to predict saltwater behavior in rivers during a tsunami. These models are structured so that the influence of the boundary of the 3D domain can be excluded without significantly increasing the calculation load. The model was used to simulate saltwater behavior in the Yodo River in Japan during a tsunami. The spatial distribution and temporal change of saltwater under various river flows were quantitatively predicted, and the effectiveness of possible countermeasures in diminishing the duration of water-intake shutdown and the presence of brackish water in upstream areas was assessed.