广西寒露风初日变化特征以及对双季晚稻抽穗安全期的影响

Characteristics of First Day Variation of“Cold Dew Wind”in Guangxi and Its Influence on Safe Heading Period of Double Cropping Late Rice

基于广西1961-2020年88个气象站观测资料,分析寒露风初日时空变化特征、50%及80%保证率初日,并结合水稻发育期资料对广西双季晚稻抽穗安全期进行分析。结果显示:(1)在时间上,广西寒露风初日以0.23 d/10a(P<0.05)的速率呈微弱提前趋势,呈不对称的“W”形特征;在空间上,广西寒露风初日呈高纬度早、低纬度晚,山区早、平地晚的“阶梯式”分布特征。(2)广西寒露风初日存在22年、12年、8年、3年4个周期变化,其中22年是广西寒露风初日的主要周期,未发生明显突变。(3)广西双季晚稻平均齐穗期以0.22 d/10a(P<0.05)的速率推迟,抽穗扬花期遭遇寒露风影响频率为21.9%。建议适当调整晚稻播种期,使其齐穗期提早3~7 d。桂中北地区应谨慎推广晚稻中晚熟品种,以避免受突发性的寒露风灾害影响。

Based on the observation data of 88 meteorological stations in Guangxi from 1961 to 2020,the temporal and spatial variation characteristics of the first day of cold dew wind,the first day of 5o%and 80%guarantee rates,and the safe heading period of double cropping late rice in Guangxi are analyzed in combination with the data of rice development period.The results show that:(1)In terms of time,the first day of the cold dew wind in Guangxi shows a slight advance trend at a rate of O.23 days per 10 years(P<0.05),showing an asymmetric W-shaped feature;in space,the first day of cold dew wind in Guangxi is characterized by a“ladder”distribution:early at high latitudes,late at low latitudes,early in mountainous areas and late on flat lands.(2)The first day of cold dew wind in Guangxi has four cycles of 22 years,12 years,8 years and 3 years,of which 22 years is the main cycle of the first day of cold dew wind in Guangxi,without obvious mutation.(3)The average full heading stage of double cropping late rice in Guangxi is delayed at a rate of 0.22 days per 10 years(P<0.05),and the frequency of encountering cold dew wind during heading and flowering is 21.9%.It is suggested that the sowing date of late rice should be adjusted appropriately to make its full heading date 3 to 7 days earlier.In order to avoid being affected by the sudden cold dew wind disaster,the middle late maturing varieties of late rice should be popularized carefully in the central and northern regions of Guangxi.