1961-2016年中国近地表大风日数时空分异特征研究

摘要

Based on the 2 481 station's data of hail days in China during 1961-2016,the temporal and spatial distribution characteristics and periodic variation of gale days in China and seven geographical regions were analyzed by using statistical methods.The results showed that:In time,the gale days in China and the seven geographical areas all showed a decreasing trend from 1961 to 2016.In the Tibet (Southeast China and Southwest China) region,the annual numbers of single station gale days were the most(least),but the ratio was the least(most).In the significance oscillation period,the whole country was 14 years;the Northeastern China,Northern and east of Northwestern China were 60 years;the west of Northwestern China,Southwestern China and Southeastern China were 7,14 and 60 years;the Tibet region were 7 and 60years.The mutation of gale days generally occured in 1991,1993,1989,1997,1986,1997,1992 and 1984 in the whole country,Northeastern China,Northern China,east of Northwestern China,west of Northwestern China,Tibet,Southwestern China and Southeastern China region,but only the east of Northwestern China and Tibet regions passed the 0.05 significant levels of test.In space,the annual average gale days showed southeast low and northwest high pattern in China from 1961 to 2016.The annual average gale days were more abundant in the central and Western Tibet,the Soutuern Qinghai,Eastern Xinjiang,Western Sichuan and Northern Inner Mongolia and Northern Gansu.These regions were dominated by positive anomaly in 1970s and 1980s,but negative in other decade.Annual gale days in most regions in China showed a decreasing trend,and fluctuation presented high in east region and low in west region beside "Hu Huanyong line".%采用1961-2016年中国2 481站的大风日数数据,利用统计方法分析了中国及七大地理分区的大风日数时空分布特征和周期变化规律.结果表明,在时间上,1961-2016年中国及七大地理分区的大风日数整体均呈减少趋势;西藏(东南和西南)地区年均单站大风日数最多(少),但减少比例最少(多).在显著振荡周期上,全国是14年,东北、北方和西北东部地区均是60年,西北西部、西南和东南地区是7、14和60年,西藏地区是7和60年.全国、东北、北方、西北东部、西北西部、西藏、西南和东南地区的年均大风日数分别在1991、1993、1989、1997、1986、1997、1992和1984年发生突变,但仅西北东部和西藏地区通过了0.05显著性水平的检验.在空间上,1961-2016年中国年均大风日数呈现出明显的东南低-西北高的空间分异格局;年均大风日数较多分布在西藏中部和西部、青海南部、新疆东部、四川西部及内蒙古和甘肃北部地区地形复杂的地区,这些地区在20世纪70和80年代以正距平为主,而在其他年代均以负距平为主.1961-2016年中国绝大多数地区年际大风日数呈减少趋势,波动特征在“胡焕庸线”两侧呈东大西小格局.