关键词: 自然正交分解（EOF）方法, ≥10℃积温, 积温区划, 一阶偏差

Abstract: The active accumulated temperature（≥10℃）at the Heilongjiang province and its surrounding areas was calculated based on Berkeley Earths latitudinal/longitudinal gridded land surface daily average air temperature dataset from 1951 to 2012.The Empirical Orthogonal Function（EOF）method was used to examine spatial and temporal variations of the active accumulated temperature anomaly in the interdecadal and interannual time scales and their impact on the rice yield of Heilongjiang province.The results show that the long term trend of the accumulated temperature anomaly in the interdecadal variations can be divided into three main phases：stationary phase Ι（1951-1993），transition phase（1993-2000）and stationary phase Ⅱ（2000-2012）.The average accumulated temperatures of the three phases are increasing as the phases progress.The average accumulated temperature of stationary phase Ⅱ is generally more than 200℃·d higher than that of stationary phase Ι in most of the Heilongjiang areas.The largest accumulated temperature increases were about 240～320℃·d in the southwestern areas of the province.During the stationary phase Ⅱ period，the 2100℃·d line of the accumulated temperature had moved across the Heihe area to reach the Daxinganling mountain range，indicating the rice has been able to grow in the Heihe area where the accumulated temperature was normally not high enough to grow rice in the past.In addition，there is quasibiennial oscillation in the yearly accumulated temperature and in the rice yield per hectare.The correlation analysis shows the interannual variations in the yearly accumulated temperature have significant effects on the yearly rice yield in Harbin，Qiqihar，Daqing，Suihua，Yichun and Jiamusi areas，but have little effect on the rice yield in the southern part of the Heilongjiang province such as Shangzhi，Mudanjiang and Jixi areas．

Key words: Empirical orthogonal functions（EOF）method, Accumulated temperature≥10℃, Accumulated temperature division, First difference