Lu Zhuo, University of Bristol, Bristol, BS8, United Kingdom, Qiang Dai, Nanjing Normal University, Nanjing, China, Xuehong Zhu, Nanjing Normal University, Key Laboratory of VGE of Ministry of Education, Nanjing, China, Dawei Han, University of Bristol, Department of Civil Engineering, Bristol, United Kingdom and Ningsheng Chen, The Institute of Mountain Hazards and Environment (IMHE), Chengdu, China