1. Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
2. Hydraulic Construction Institute, Vietnam Academy for Water Resources, Hanoi, Vietnam
3. Vietnam Department of Survey, Mapping and Geographic Information, Hanoi, Vietnam
4. VNU Center for Development at Hoa Lac Campus, Vietnam National University, Hanoi, Vietnam
5. Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan