江西省双季晚稻寒露风影响评估

为定量评价寒露风对江西省双季晚稻的影响,依据1981—2013年江西省81个常规气象观测站9月1日—10月10日逐日平均气温、最低气温资料和1991—2012年江西省14个农业气象观测站双季晚稻灾害调查资料,研究江西省双季晚稻寒露风影响评估模型和等级划分标准,并利用江西省农业气象试验站2010—2013年晚稻分期播种试验资料进行验证。结果表明,在晚稻寒露风发生期间,降温幅度、过程平均气温、极端最低温度和低温持续时间对水稻冷害具有同等重要的作用,4个因子同时出现或部分出现异常均可以造成不同程度的冷害。在综合考虑了上述4个因子的基础上,结合主成分分析法构建寒露风影响评估模型和等级划分标准,其分期播种试验检验评估等级与实际等级完全一致的占80%;运用模型对江西省2006、2011年2次明显寒露风天气过程进行评估,评估准确率较高,达87.5%;表明所建立的模型可以用来定量评价江西省各市(县)晚稻寒露风发生程度。据此确定的寒露风评价指标为:寒露风指数(CDWI)≥0.70时为重度寒露风,晚稻减产15%;CDWI在0.50~0.70时,发生中度寒露风,晚稻减产10%~15%;CDWI在0.30~0.50时,发生轻度寒露风,晚稻减产5%~10%。

Impact assessment of cold-dew wind on double-cropping late rice in Jiangxi Province

In order to quantify the impact of cold-dew wind on double-cropping late rice in Jiangxi Province,an impact assessment model and grading standards of cold-dew wind to late rice were studied based on 1981-2013 daily average and minimum temperature data from 81 stations,and 1991-2012 disaster investigation data of late rice from 14 agricultural meteorological observation stations.The model was verified through sowing by stage experiment data in agrometeorological experiment station of Jiangxi Province during 2010-2013.The results showed that the decreasing extent of temperature,averge temperature of the process,extreme minimum temperature,and low temperature duration had the same important role in the chilling injury of rice.Four factors appeared at the same time or part of four factors appeared could cause different degree of chilling injury.Considering the above four factors,the assessment model and grading standards of cold-dew wind to late rate were established by using principal component analysis method,and were tested through sowing rice by stage.The testing results proved the assessment and the actual grade were 80% identical,and the accurate rate of model used to assessment two obviously cold dew wind weather process in 2006 and 2011 reached 87.5% accuracy.The model established in this paper could be used to quantify the impact of cold-dew wind on late rice of each county (city).When the index of cold-dew wind was more than 0.70(severe damage cold-dew wind) the yield reduction rate of late rice was more than 15%;When the index was between 0.50-0.70(moderate damage cold-dew wind) the yield reduction rate of late rice was between 10%-15%;When the index was between 0.30-0.50(slight damage cold-dew wind) the yield reduction rate of late rice was between 5%-10%.