Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity Xi''an Shannxi 710127 ChinaInstitute of Earth Surface System and Hazards College of Urban and Environmental Sciences Northwest University Xi''an Shannxi 710127 China;
School of Environmental Science Nanjing Xiaozhuang University Nanjing Jiangsu 211171 China;
School of History and Tourism Shaanxi Sci-Tech University Hanzhong Shannxi 723000 China;
Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science&Technology Nanjing Jiangsu 210000 China;
albedo; black carbon; snow grain size; quantitative estimation;