[1] Sichuan Agr Univ, Coll Management, Sichuan Ctr Rural Dev Res, Chengdu 611130, Sichuan, Peoples R China
[2] Geog Natl Condit Monitoring Engn Res Ctr Sichuan, 2 Xinjun St, Chengdu 610599, Sichuan, Peoples R China
[3] China West Normal Univ, Coll Land & Resources, Nanchong 637000, Peoples R China
[4] Chinese Acad Sci, Inst Mt Hazards & Environm, Chengdu 610041, Sichuan, Peoples R China