河北省玉米高温热害监测与定量化评估指标研究

Monitoring and evaluation indices of high temperature damage for maize in Hebei province

高温热害是影响玉米(Zea Mays)生产的重要农业气象灾害。文中利用河北省1981-2020年26个农气站玉米观测资料(包括品种、发育期、灾情、土壤墒情、产量要素)和逐日气象资料,采用秩和检验法,依据Bayes判别准则,建立了玉米拔节至灌浆期高温热害指标;基于致灾因子与减产率之间的相关关系,采用权重系数法构建灾情指数,并建立灾损评估模型;有序样本聚类分析法结合高温年减产率,划分灾情等级及等级阈值;依据风险分析原理分析玉米高温风险。结果显示:玉米拔节至灌浆期高温显著影响因子和指标主导因子为32℃以上气温累计出现时间和积温,建立的高温指标准确率在96%以上;灾情指数与减产率显著正相关(P<0.01),能够反应高温对产量的影响;灾损评估模型准确率在86%以上;灾情划分为轻度、中度、重度、特重度四个等级,等级阈值判断结果与实际情况相符;夏玉米区高温风险明显大于春玉米区,以夏玉米拔节和抽雄期风险较大,其中,邢台和邯郸两市中东部、衡水西部和南部、石家庄东南部地区为高风险区。

High temperature damage(HTD)is an important natural disaster for maize.Based on observed data(including cultivars,growing stage,disasters,soil moisture,and yield components)and daily climatic data of 26 agro-meteorological stations from 1981 to 2020,the monitor indices of HTD from jointing to filling stages were established by using rank sum test and Bayesian discriminant analysis.Based on relationship between temperature factors and yield loss rate,intensity indices of HTD were designed through weight coefficients of factors.Loss evaluation models of HTD were established based on intensity indices.The disaster grade and thresholds of HTD were obtained by cluster analysis and yield reduction rate.Based on risk analysis principle of disaster,risks of HTD were analyzed.The results showed that time span and accumulated temperature higher than 32℃are the main factors for HTD.The accuracies of monitor indices and loss evaluation models are over 96%and 86%,respectively.The intensity indices have significant positive correlations with yield components(P<0.01),and can reflect the impact of HTD on yield.HTD are divided into four grades of slight,moderate,severe,and extreme severe,and the estimated result coincides with actual conditions.Risk of HTD for spring maize is less than that for summer maize.Risk of HTD for jointing-booting and tasseling-flowering stages are higher,and high risk region mainly distributed in central and eastern of Xingtai and Handan,westward and southern of Hengshui,and southeast of Shijiazhuang.