江西省双季早稻灌浆乳熟期高温热害影响评估

依据江西省14个农业气象观测站2000-2013年农业气象观测资料、6月下旬-7月中旬逐日最高气温资料，探讨早稻高温热害的主要影响因子，建立江西省双季早稻灌浆乳熟期高温热害影响评估模型，并利用2000-2012年早稻产量、灾害调查资料和2012-2013年早稻分期播种试验资料进行验证。结果表明，过程最大升温幅度、过程极端最高气温和高温持续日数，为早稻高温热害的主要影响因子。在此基础上，结合主成分分析法构建灌浆乳熟期高温热害评估和指数计算模型，其历史回代和分期播种试验检验的准确率均比较高，可以用来定量评价江西省早稻灌浆乳熟期高温热害发生程度。据此确定的高温热害评价指标为：高温热害指数（HTDI）≥0.60时为重度高温热害，早稻减产率＞10%；HTDI在0.30～0.60时，发生中度高温热害，早稻减产5%～10%；HTDI在0.10～0.30时，发生轻度高温热害，早稻减产小于5%。

Impact Assessment on High Temperature Damage to Early Rice at Filling Milk Stage in Jiangxi Province

Based on observed data from 14 agricultural meteorological stations in Jiangxi province from 2000 to 2013，and daily maximum temperature data from last 10 days in June to early 10 days in July，the main influence factors and assessment model were established. The model was verified by rice yield and investigated disaster data from 2000 to 2012 and experiment data during 2012-2013. The results showed that the main influence factors of high temperature damage to rice were increasing extent of temperature，extreme maximum temperature and high temperature duration. Based on this，the assessment model of high temperature damage was established by using principal component analysis method，and tested through historic back and sowing rice by stage.The testing results indicated that the accurate rate of model was higher，which could be used to evaluate impact quantitatively of high temperature damage to rice.The assessment factors could be defined as severe damage when HTDI≥0.60，the yield reduction rate of early rice was more than 10%; moderate damage when 0.30≤HTDI<0.60，the yield reduction rate of early rice was between 5%-10%;slight damage when 0.10≤HTDI<0.30，the yield reduction rate of early rice was less than 5%.