近50年广西春播期低温阴雨的变化特征

目的]研究近50年广西春播期低温阴雨的变化特征。方法]选取广西88个气象站1961～2010年逐日平均气温资料,统计逐年春播期低温阴雨日数、低温阴雨结束期,利用线性倾向计算、阶段性分析、Morlet小波分析、相关分析等气候诊断分析方法,分析了近50年广西春播期低温阴雨的变化特征,并分析气候变暖对春播期低温阴雨日数和结束期的影响。结果]1961～2010年广西各地春播期低温阴雨日数多年平均值在3.5～23.2 d,其地域分布特点是东北多、西南少,山区多、河谷少;结束期的地域分布特点是东北部晚、西南部早,山区晚、河谷早。近50年广西春播期低温阴雨日数呈略减少趋势,低温阴雨结束期呈略偏早趋势;低温阴雨日数和结束期的阶段性变化特征较明显,20世纪80年代初～90年代中期低温阴雨日数明显偏多、结束期明显偏迟,90年代末以后低温阴雨日数明显偏少、结束期明显偏早;低温阴雨日数存在4、6、8、10～14年的周期振荡信号,结束期存在6、12～14年周期振荡信号。广西春播期低温阴雨日数、结束期与2月中旬～4月上旬平均气温相关显著,气候变暖使低温阴雨日数趋于减少,结束期趋于提前。结论]该研究为当地进一步了解低温阴雨的发生规律、趋利避害、合理安排生产以及开展相关研究提供参考。

Variation Characteristics of Low Temperature and Rainy Weather during Spring Sowing Period in Guangxi in Recent 50 Years

Objective] The research aimed to study the variation characteristics of low temperature and rainy weather during spring sowing period in Guangxi in recent 50 years.Method] Based on the daily mean temperature data from 1961 to 2010 at 88 meteorological stations in Guangxi,the variation characteristics of low temperature and rainy weather during spring sowing period in Guangxi in recent 50 years were analyzed by using linear tendency calculation,phased analysis,Morlet wavelet analysis and correlation analysis.Moreover,the influences of climate warming on days and end date of low temperature and rainy weather in spring sowing period were analyzed.Result] The average days of low temperature and rainy weather during spring sowing period in Guangxi from 1961 to 2010 was during 3.5-23.2 d.The regional distribution characteristics were that it was more in northeast and mountain zone,and less in southwest and valley.The regional distribution characteristics of end date were that it was late in northeast and mountain zone,and early in southwest and valley.The days of low temperature and rainy weather during spring sowing period in Guangxi in recent 50 years slightly presented decrease trend,and the end date of low temperature and rainy weather slightly presented advance trend.The phased variation characteristics of days and end date of low temperature and rainy weather were obvious.The days of low temperature and rainy weather from early 1980s to metaphase of 1990s was obviously more,and the end date was obviously later.After the 1990s,the days of low temperature and rainy weather was obviously less,and the end date was obviously earlier.The days of low temperature and rainy weather had periodic oscillation signal of 4,6,8,10-14 years.The end date had periodic oscillation signal of 6,12-14 years.The days and end date of low temperature and rainy weather in Guangxi during spring sowing period significantly related to average temperature from middle dekad of February to first dekad of April.The climate warming made that the days of low temperature and rainy weather tended to decrease,and the end date tended to advance.Conclusion] The research provided reference for locals further understanding occurrence rule of low temperature and rainy weather,going after profits and avoiding disadvantages,reasonably arranging production,carrying out correlated research.