1. Professor, Dept. of Geography and Geology, Paris-Lodron-Univ. Salzburg, 5020 Salzburg, Austria.
2. Postdoctoral, Dept. of Geography and Geology, Paris-Lodron-Univ. Salzburg, 5020 Salzburg, Austria (corresponding author).
3. Professor, School of Ecological and Environmental Sciences, East China Normal Univ., Shanghai 200241, China.
4. Associate Professor, School of Land Science and Technology, China Univ. of Geosciences, Beijing 100083, China.