Author Contributions
Wang XiaoLong conceived and supervised the study.Gao Shan carried out the spatial . modeling, the Least Costs Path analysis, interpretation of results, map design and draft writing. Lv JiaNing also contributed to the data filtering and the map design. Wang XiaoLong, Wang HaoNing and Huang LiYa contributed to the discussion and manuscript writing. Xu GuoYong provides DEM data and help in cartography. All authors significantly contributed to the final manuscript and gave final approval for publication.