东北地区水稻延迟型冷害时空特征及其与气候变暖的关系

利用水稻延迟型冷害分级指标和1951-2010 年东北地区101 个气象台站的逐日气温资料，采用累计距平、相关系数、气候倾向率、趋势系数等方法分析东北地区水稻延迟型冷害时空变化特征及其对气候变化的响应。结果表明：蒙东地区西部、吉林东部和黑龙江交界延迟型冷害出现的频率较大，辽宁中南部延迟型冷害出现的频率较小。东北地区严重冷害出现频率高于轻度冷害和中度冷害。轻度、中度、严重延迟型冷害都呈下降的趋势，特别在1994 年后延迟型冷害呈快速下降的趋势，东北地区水稻延迟型冷害与气候变暖有着较好的对应关系，5-9 月平均气温和延迟型冷害呈明显反相关，5-9 月平均气温升高1℃，水稻延迟型冷害减少约45次。

Spatial-temporal characteristics of prolong-type rice chilling damage and its relationship with climate change in Northeast China

Northeast China is one of the major rice producing areas in China, because of the lack of heat, and rice growth is more sensitive to temperature. Temperature becomes the major limitations to local rice growth. Analysis of spatial-temporal characteristics of rice chilling damage in Northeast China under the background of climate warming is of important significance for rice chilling damage defense and its response to climate change. Spatial-temporal characteristics of prolong-type rice chilling damage and its response to climate change in Northeast China were analyzed based on classification index of prolongtype rice chilling damage and daily temperature data from 101 stations during 1951-2010, and by using the accumulative anomaly, correlation coefficient, and climatic trend rate and tendency coefficient. The results show that the frequency for prolong-type rice chilling damage is larger to the west of eastern Inner Mongolia (Mengdong), the boundary between eastern Jilin Province and Heilongjiang Province, the frequency for this damage is smaller in the southern-central Liaoning Province. The frequency of severe prolong-type rice chilling damage is higher than that of light and medium damages during 1951-2010 in Northeast China. The light, medium and severe prolong-type rice chilling damages show a downward trend, prolong-type rice chilling damage presents a trend of rapid decline particular after 1994. The downward trend is more significant in the central Heilongjiang and the northwest of Mengdong region, and the downward trend of prolong-type rice chilling damage shows no significance in Liaoning, the south of Mengdong region, the south of Jilin and the north of Heilongjiang. Prolong-type rice chilling damage in Northeast China has a better relationship with climate warming. The average temperature from May to September and prolong-type rice chilling damage has obvious anticorrelation, the average temperature from May to September rises by 1℃, and prolong-type rice chilling damage in Northeast China reduces about 45 times. The periodic change of the average temperature from May to September and prolong-type rice chilling damage shows the obvious reverse phase.