华北平原夏玉米不同生育阶段大风灾害危险性评估

Assessment on Risk of Gale Disaster in Different Growth Stages of Summer Maize in North China Plain

[目的]大风灾害是制约社会经济发展的主要气象灾害之一,科学评估大风灾害危险性对夏玉米生产防灾减灾具有重要意义。[方法]基于夏玉米拔节后不同生育阶段最大风速和大风日数的时空分布特征,筛选并利用历史倒伏案例验证区域适用的夏玉米大风倒伏判别指标,运用风险区划方法,评估了华北平原夏玉米不同生育阶段的大风倒伏危险性。[结果](1)1980—2019年以来,华北平原夏玉米拔节后最大风速和大风日数均呈显著的波动式下降趋势,空间上由东部向中西部逐渐递减。(2)夏玉米拔节后以轻度倒伏为主,区域平均的倒伏发生概率为44.5%,重度倒伏发生概率最小,为7.8%;拔节—抽雄阶段最易发生倒伏。(3)夏玉米拔节后大风倒伏概率总体呈逐渐降低趋势,但2011年以后局部地区拔节—抽雄期大风倒伏有极端加剧的趋势。(4)夏玉米大风灾害危险性分布整体上呈现由东向西逐渐递减的趋势,东部为高风险地区,中部大部分地区为中风险区,北部和西部部分地区为低风险地区。[结论]尽管近年来最大风速和大风日数均呈下降趋势,但华北平原局部地区夏玉米大风倒伏有加剧趋势,需要加强防灾减灾相关建设。

[Objective]Gale disaster is one of the main meteorological disasters that restrict social and economic development.The aim of this study is to scientifically assess the risk of gale disaster,which is of great significance for disaster prevention and mitigation of summer maize production.[Methods]Based on the spatial and temporal distribution characteristics of maximum wind speed and gale days at different growth stages of summer maize after jointing,the regionally applicable gale lodging discriminant indexes of summer maize were screened and verified by historical lodging cases,and the risk of gale lodging at different growth stages of summer maize in North China Plain was evaluated by risk zoning method.[Results](1)From 1980 to 2019,the maximum wind speed and gale days after jointing of summer maize in the North China Plain showed a significant fluctuating downward trend,and gradually decreased from the east to the middle and west in space.(2)Mild lodging was the main lodging type of summer maize after jointing,and the regional average lodging probability was 44.5%,and the probability of severe lodging was the lowest(7.8%).The jointing-tasseling stage was most prone to lodging.(3)The probability of gale lodging after jointing of summer maize showed a decreasing trend,but after 2011,the gale lodging in the jointing-tasseling period in some areas showed an extreme trend.(4)The risk distribution of summer maize gale disaster showed a decreasing trend from east to west.The eastern part was a high-risk area,most of the central part was a medium-risk area,and the northern and western parts are low-risk areas.[Conclusion]Although the maximum wind speed and the number of gale days have shown a downward trend in recent years,the lodging of summer maize in some areas of the North China Plain has intensified,and it is necessary to strengthen the construction of disaster prevention and mitigation.