1. Graduate School of Oceanology, Sediment Hazards and Disaster Risk Laboratory, Kobe University, Kobe 658-0022, Japan
2. Faculty of Geography, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
3. Faculty of Agriculture, The University of Tokyo, Tokyo 113-8654, Japan
4. Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan