*A T M Sakiur Rahman¹、Takahiro Hosono¹、Yasuhiro Tawara²、Dennis Boateng¹、Jun Shimada¹ (1.Department of Earth and Environmental Science, Kumamoto University, Japan、2.Geosphere Environmental Technology Corporation, NCO Kanda, Awajicho, Chiyoda-ku, Tokyo 101-0063, Japan)