黔东南近40年水稻安全生长期的变化

利用贵州省黔东南16个观测站点1961~2000年的逐日平均气温记录,分析了黔东南1961~2000年水稻安全生长期的变化趋势。结果表明,在近40年中,黔东南水稻安全生长期缩短了7.0天,400m以下高度层缩短了10.6天,400~600m高度层缩短了6.4天,600~800m高度层增加了1.4天,800m以上高度层缩短了4.8天。20世纪80年代是黔东南水稻安全生长期缩短最明显的时期,1980年是黔东南1961~2000年中水稻安全生长期最短的年份。从水稻安全生长期变化趋势的不同高度层差异看,黔东南600~800m高度层上有不明显的延长趋势,600m以下和800m以上高度层上有明显的缩短趋势。

Variation of Safe Growth Period for Rice in Recent 40 Years in Southeastern Guizhou

The variation trend of the safe growth period for rice in recent 40 years over the southeastern Guizhou Province is analyzed on the basis of the daily mean air temperature data of 16 meteorological stations from 1961 to 2000.The results indicate that the rice safe growth period decreased by 7 days in recent 40 years over the southeastern Guizhou,by 10.6 days,6.4 days,and 4.8 days for altitudes below 400 m,400 to 600 m,over 800 m,respectively.On the contrary,at the altitudes between 600 m and 800 m,the growth period increased by 1.4 days.In the 1980s,the growth period decreased obviously with the minimum in 1980.In conclusion,the rice safe growth period took on an slight increasing trend at altitudes between 600 m and 800 m,and an obvious decreasing trend at altitudes below 600 m,as well as over 800 m.