2015年中国气象局气候变化专项No.CCSF201532;国家科技支撑计划项目No.2014BAC16B03;2015年四川省气象探测数据中心课题;the 2015 Climate Change Project of China Meteorological Administration No.CCSF201532,the National Science and Technology Support ProgramNo.2014BAC16B03 and the 2015 Project of Sichuan Meteorological Observation and Data Centra