[1] China West Normal Univ, Sch Geog Sci, Nanchong 637009, Peoples R China
[2] China West Normal Univ, Sichuan Prov Engn Lab Monitoring & Control Soil Er, Nanchong 637009, Peoples R China
[3] China West Normal Univ, Inst Jialing River Basin, Nanchong 637009, Peoples R China
[4] Southwest Univ, Sch Geog Sci, Chongqing Key Lab Karst Environm, Chongqing 400715, Peoples R China