【摘要】 构建考虑前效影响的作物逐日干旱指数是研制作物干旱灾变逐日动态监测、预警技术的基础。针对黄淮海平原冬小麦干旱,利用1981—2023年逐日气象数据、冬小麦干旱灾情史料和冬小麦发育期数据,厘定冬小麦不同发育阶段干旱前效影响系数,构建能反映冬小麦干旱动态特征的逐日干旱指数,并以2022年冬小麦干旱过程为例,开展基于干旱指数的典型过程追踪应用。结果表明:冬小麦越冬前、越冬期、返青-拔节期、抽穗-灌浆期和乳熟-成熟期干旱前效影响系数分别为0.93、0.88、0.81、0.92和0.95,0.90为冬小麦全生育期的最佳前效影响系数值;在预留独立灾情样本、典型站点(山东济阳站)1981—2023年长序列、典型年份(2014—2015年)区域尺度有效性检验中,构建的逐日干旱指数显示了时间、空间有效性。以2022年4—5月冬小麦干旱为例,干旱指数可有效反演单站点和区域冬小麦干旱灾变逐日动态过程。研究结果可为作物干旱逐日监测、预警及实时动态评估技术的研制提供支撑。更多还原

【Abstract】 Drought is a dynamic,ongoing process.Drought index,calculated over years, months,or specific stages of crop development as statistical periods,cannot accurately reflect the daily drought status of crops,and is somewhat insufficient in the research of daily dynamic monitoring of crop drought.Therefore,construction of a daily drought index considering the impact of the previous effect is an important support for the research and development of daily dynamic monitoring and early warning technology for crop drought occurrence,development,and recovery process.Winter wheat drought in Huang-Huai-Hai Plain is targeted in this study,and daily meteorological data from 1981 to 2023,historical data on wheat drought,and data of winter wheat phenology are used to the construction of daily drought index(I_d),considering the water supply and demand of winter wheat at different stages.Coefficients of the previous effect of drought at 5 growth stages of winter wheat,i.e.,before overwintering,during overwintering,greening-jointing,heading-filling,milk-maturity are determined,based on the distance between the drought and the non-drought samples.In addition,the effectiveness of I_d is validated using methods involving reserved independent samples,long time series,and spatial regional scales.Afterward,the drought process affecting winter wheat in 2022 is taken as an example to analyze the application of drought index I_d-based typicat process tracking.Results show that the coefficients representing the previous effect of drought before winter wheat are 0.93,0.88,0.81,0.92,and 0.95 for wheat before overwintering,during overwintering,greening-jointing,heading-filling and milk-maturity,respectively.The optimal previous effect coefficient value for the entire growth period of winter wheat is 0.90,indicating that the current drought is related to the drought conditions approximately 42 d prior.The accuracy of the reserved independent sample test for effectiveness of I_d is 88.40%;I_d of each stage in the years with drought and nondrought records shows a significant difference in typical station(Jiyang,Shandong) analysis,with stations(passing the test of 0.001 level) during typical years(2014—2015) with recorded drought disasters are located in areas characterized by low regional I_d values.The constructed drought index I_d for winter wheat demonstrates both temporal and spatial validity,providing valuable support for the development of daily monitoring,early warning,and real-time dynamic evaluation technologies for crop drought.The winter wheat drought index I_d can effectively represent the dynamic process of winter wheat drought in 2022,not only at targeted stations,but also on regional scales.The research findings can support the development of technologies for daily monitoring,early warning,and real-time dynamic evaluation of crop drought.更多还原