1. a Centre for Environmental Remote Sensing (CEReS) , Chiba University, 1-33 Yayo-icho , Inage , Chiba , 263-8522 , Japan
2. b Institute for Global Environmental Strategies, 2108-11 Kamiyamaguchi , Hayama , Kanagawa , 240-0115 , Japan
3. c Institute of Geography, Vietnamese Academy of Science and Technology (VAST) , 18-Hoang Quoc Viet , Hanoi , Vietnam