河南省夏玉米不同生长阶段干旱风险分析

Drought Risk Assessment of Summer Maize at Different Growth Stages in Henan Province

【目的】研究夏玉米各生长阶段的抗干旱风险,为预防夏玉米受干旱影响导致产量和品质下降,降低干旱造成的损失提供理论依据。【方法】本研究利用河南省16个气象站1981—2019年的逐日气象数据,以作物水分亏缺指数(CWDI)为评判指标,根据《北方夏玉米干旱等级》(QX/T 260—2015)对该地区玉米5个生长发育时期进行了干旱等级划分,分析各等级干旱发生的频率、干旱风险指数的时空分布规律。【结果】河南省夏玉米各生长阶段干旱发生总频率在豫北地区最高,其次是豫中和豫东。干旱发生总频率均在夏玉米抽雄—乳熟期最大,高达96%以上,且以中旱和特旱为主。不同等级干旱发生的频率具有差异性,但豫南地区各生长阶段各等级干旱发生的频率相对较低。在夏玉米播种—出苗、出苗—拔节期,河南省各地区干旱风险指数呈由南向北逐渐增加的空间分布特征;在拔节—抽雄、抽雄—乳熟和乳熟—成熟期,该指数基本在30以上。【结论】各地区夏玉米在拔节—抽雄、抽雄—乳熟和乳熟—成熟期干旱发生的风险均较高。夏玉米各个生长阶段干旱发生的风险均为豫北地区最高,豫南地区最低。应重点关注豫北地区的防旱减灾工作。

【Objective】The study is to analyze the drought risks of summer maize in different growth stages,which has important reference value for guiding the formulation of drought prevention measures and reducing losses caused by drought.【Method】This study used daily meteorological data from 16 meteorological stations in Henan province from 1981 to 2019,and used the Crop Water Deficiency Index(CWDI)as the evaluation index.According to the Drought Grade of Summer Maize in Northern China(QX/T 260-2015),drought levels were divided for the 5 growth stages of summer maize.The frequency of drought occurrence,drought risk index,and their spatio-temporal distribution patterns at each level were analyzed.【Result】The total frequency of drought occurrence in different growth stages of summer maize is highest in the northern region of Henan,followed by the central and eastern regions of Henan.The total frequency of drought occurrence is highest during the tasseling to milking period,reaching over 96%,mainly consisting of moderate and extreme drought.The frequency of drought occurrence varies among different levels,but the frequency of drought occurrence in different growth stages and levels in southern region of Henan is relatively low.The drought risk index of summer maize in Henan province shows a spatial distribution pattern of gradually increasing from south to north during the sowing to emergence and emergence to jointing stages.The drought risk index of the entire Henan province is basically above 30 during the jointing to tasseling,tasseling to milking,and milking to maturity stages.【Conclusion】The risk of drought occurrence in summer maize is high in various regions during the jointing to tasseling,tasseling to milking,and milking to maturity stages.The risk of drought occurrence in various growth stages of summer maize is the highest in northern region of Henan and the lowest in southern region of Henan.Special attention should be paid to drought prevention and disaster reduction in the northern region of Henan.