School of Economics and Management Tianjin Polytechnic University Tianjin 300387 China;
School of Geography and Tourism Qufu Normal University Rizhao 276826 Shandong China;
State Key Laboratory of Earth Surface Processes and Resource Ecology School of Natural Resources Faculty of Geographical Science Beijing Normal University Beijing 100875 China;
Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China;
