中文摘要：

ZI-IANG Huaming was born in Shanxi Province, China, in 1980. He received the M.S. degree from the Northwest Normal University, China, in 2007. He is currently working in Thtmder Prevention and Observation Center of Shanxi Province, China. E-mail： zhanghuaming980@163.com YUAN Ping was born in Gansu Province, China, in 1963. She received the Ph.D. degree from the Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, China,in 2003. She is currently working in Northwest Normal University, China. E-mail： yuanp@nwnu.edu.cn