Quantitative evaluation of saltwater concentration distribution using optical method for saltwater intrusion experiment by Mini-MACRO

Sato, Hisashi; Takasu, Tamio*; Sawada, Atsushi 

In coastal area, the density difference between seawater and freshwater causes seawater intrusion under the freshwater. The methodology to evaluate saltwater distribution due to density driven flow might be crucial for bringing forward the radioactive waste disposal project. Although the extensive verification studies of the model for the salt water wedge have been reported, verification issue is still under the discussion. The saline concentration distribution in transition zone of salt water and fresh water was not evaluated, quantitatively. In order to obtain verification data of a numerical code that consider saltwater density distribution, we developed the quantitative measurement method by optical method for Mini-MACRO. And, quantitative concentration distribution data of saltwater wedge could be obtained. As a result, we showed that the width of the transition zone was narrower than the Henry's semi analytical result by quantitative data.