广东冬季寒害指标研究

Study on index for winter’s chilling damage in Guangdong Province

用广东省 22个分布较均匀的代表站 1957年 12月至 2001年 2月冬季逐日平均气温和最低气温资料,以该省南亚热带作物的生物学下限温度为依据,从这些作物受寒害的起点温度 (环境温度≤5. 0℃)出发,提出了寒害过程的概念和明确的定义,并用寒害过程低温的强度 (日最低气温 )X1、持续时间(天数)X2及其综合作用的物理量负积温X3这 3个指标来描述寒害的强度,研究了广东历年冬季寒害的变化。从 3个特征向量场中找出了一个物理意义清晰、方差贡献率大 (大于 75% )的主要分量,将其定义为综合寒害指标。分析表明:广东冬季综合寒害指标能较好反映农作物受灾程度。

By using data of daily mean and lowest temperatures from 22 meteorological stations in Guangdong Province from December through next February during 1957-2001 and based on biological lower limit temperature of tropical crops in southern Asia, the concept and definition of chilling damage process were presented clearly. Three eigen quantities including the daily lowest temperature, successive days of the low temperatur and their comprehensive effect——negative accumulative temperature were defined. A dominant component with clear physical sense and large variance contribution among these three eigenvector fields were searched and defined as a synthetic chilling damage index. Analysis shsws that the synthetic chilling damage index reflects seriousness of crop's chilling damage better.