1. College of Environment and Planning; Henan University, Kaifeng; Henan Province China
2. Department of Geology; University of Illinois; Natural History Building Urbana IL USA
3. Departments of Geology, Geography and GIS and Mechanical Science and Engineering; University of Illinois; Natural History Building Urbana IL USA
4. Civil & Environmental Engineering, Ven Te Chow Hydrosystems Laboratory; University of Illinois; Urbana IL USA