College of Geography and Environmental Science Northwest Normal University Lanzhou 730070 China;
College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 China;
College of Geography and Environmental Science Northwest Normal University Lanzhou 730070 China;
Faculty of Geomatics Lanzhou Jiaotong University Lanzhou 730070 China;
State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China;
Key Laboratory of Ecohydrology of Inland River Basin/Gansu Qilian Mountains Ecological Research Center Northwest Institute of Eco-environment and Resources CAS Lanzhou 730000 China;
College of Geography and Environmental Science Northwest Normal University Lanzhou 730070 China;
College of Geography and Environmental Science Northwest Normal University Lanzhou 730070 China;
School of Urban Economics and Tourism Culture Lanzhou City University Lanzhou 730070 China;