江苏省小麦赤霉病综合影响指数构建及时空变化特征

Construction of the comprehensive impact index for wheat scab and its spatiotemporal variations in Jiangsu Province

基于2002—2017年江苏省13个市、南通市通州区、盐城市建湖县和阜宁县的小麦赤霉病病穗率资料与生育期观测资料及相应时段内的逐日气象数据,采用灰色关联、合成分析、相关普查、百分位法等统计方法,构建了小麦赤霉病综合影响指数和等级指标,并进行独立样本检验和历史回代检验,依据建立的赤霉病等级指标分析了江苏小麦赤霉病的时空变化特征。结果表明:累计雨日、平均相对湿度、平均气温是影响小麦赤霉病的关键气象因子,权重分别为0.348、0.340、0.312,由此构建的综合影响指数可以很好地反映江苏小麦赤霉病的发生情况;基于综合影响指数建立的等级指标能较好地反演出赤霉病不同发生程度的时空变化特征,近16年江苏小麦赤霉病维持着南重北轻的空间格局,但赤霉病发生最严重的区域有所变化,江淮之间东部沿海地区(主要集中在盐城)赤霉病大发生的次数明显高于其他地方,自2010年江苏各地小麦赤霉病发生严重的频次有所增加。本研究可用于赤霉病的预测和影响评估,对赤霉病的科学防控具有指导意义。

Based on the data of the spike rate of wheat scab,winter wheat phenology,and the daily weather data observed in 13 cities of Jiangsu Province,as well as in Tongzhou District(Nantong City)and Jianhu and Funing counties(Yancheng City),a comprehensive impact index and classification indicators for wheat scab were established by statistical methods,including grey correlation,synthetic analysis,census and percentile analysis.The proposed index and indicators were calibrated and validated using empirical data.Then,they were used to analyze the temporal and spatial patterns of wheat scab in Jiangsu Province.Cumulative rainy days,average relative humidity,and average temperature were key meteorological factors affecting wheat scab.Their weights were 0.348,0.340,and 0.312,respectively.The proposed comprehensive impact index on the basis of these meteorological variables could indicate the situation of wheat scab occurrence in Jiangsu.The classification indicators according to the comprehensive impact index could retrieve the spatiotemporal variations of wheat scab.In recent 16 years from 2002 to 2017,the occurrence of wheat scab in Jiangsu decreased from south to north.However,areas with the most serious wheat scab shifted.The occurrence probability of serious wheat scab in the eastern coastal areas between the Yangtze and Huaihe rivers(mainly in Yancheng City)was significantly higher than that in other areas.Since 2010,serious wheat scab broke out more frequently in Jiangsu,probably due to climate warming.Our results can be used for the prediction and impact assessment of wheat scab,providing guidance for the effective prevention and control of the disease.