1. China University of Geosciences,School of Computer Science,Wuhan,P. R. China,430074
2. Changjiang Institute of Survey, Planning, Design and Research,Wuhan,China,430010
3. Sun Yat-sen University,School of Geography and Planning,Guangzhou,China,510275
4. Nanchang Institute of Technology,Jiangxi Province Key Laboratory of Water Information Cooperative Sensing and Intelligent Processing,Nanchang,China,330099