1980～2009年长江下游地区油菜冻害时空特征研究

Temporal-Spatial Characteristics of Rape Freezing Injury in the Lower Reaches of the Yangtze River During 1980-2009

利用1980~2009年长江下游地区的气象数据和灾害资料,首先对油菜越冬期最低温度<-5℃天数和蕾花期最低气温<0℃天数进行了时空特征分析;然后对比了不同年代油菜关键生育期低温冻害的变化特点。结果表明:1980年以来,越冬期最低温度<-5℃的天数和蕾花期最低气温<0℃的天数均呈下降趋势;低温天数较大的地区是安徽和江苏省,低温天数较大的时期是1980s,1980~2009年油菜越冬期和蕾花期冻害出现的次数均有所减少,出现越冬期冻害的年份较少,发生蕾花期冻害的年份较多。安徽与江苏省是出现越冬期冻害的主要地区;除上海以外,其他省份均有半数以上的年份发生蕾花期冻害。长江下游地区可以采取育种、栽培和耕作等措施缓解关键生育期低温冻害对油菜产量的影响。

In this study,by using meteorological and disaster data in the lower reaches of the Yangtze River from 1980 to 2009,the days of minimum temperature less than〈-5℃ in overwintering period and the days of minimum temperature less than 0℃ during bud to flowering stage were analysed with temporal-spatial characteristics; the changes of freezing injury during rape key growth stages were compared in different ages. The results indicated that,the days of minimum temperature 〈-5℃ in overwintering period and the days of minimum temperature 〈0℃ during bud to flowering stage showed a decreasing trend since 1980. There were more days of low temperature in Anhui and Jiangsu provinces,and the age with a higher number of days of low temperatures was 1980 s. The numbers of rape freezing injury during overwintering period,bud and flowering stage had declined in the lower reaches of the Yangtze River during 1980 ~ 2009. There were more years of frost damage at bud and flowering stage and fewer years of freezing injury in overwintering period. Anhui and Jiangsu provinces were the main regions with freezing injury in overwintering period. Apart from Shanghai,freezing injury during bud to flowering stage was occurred more than half of the years in other provinces. It is suggested to take countermeasures in breeding,cultivation and farming to mitigate the impact of freezing injury during key growth stages on rape production in the lower reaches of the Yangtze River.