1961—2010年南方双季稻区气候资源变化分析

中国南方双季稻播种面积占到全国水稻的85%以上, 研究该区域对气候变化的响应有助于科学地规划和管理双季稻生产。以江南、华南双季稻区为研究对象, 选取1961—2010年南方双季稻区275个数据完整性较好的气象观测站点, 对双季稻区平均气温、日照时数、降水量等气候资源演变规律及其可能变化的分析表明: 该研究区域正处于气温显著上升阶段, 气候倾向率为2℃/(10 a), 尤其是1997年气温突变之后升温幅度进一步增大, 气候倾向率增大为5℃/(10 a), 且秋冬季增温更为显著。研究区域降水年际波动较大, 无明显增减趋势; 从季节上看, 春秋降水有减少趋势, 而冬夏有增加趋势, 且使降水分布更为集中。从空间演变看, 双季稻区气候资源的演变趋势存在较大的差异, 其中华南稻区呈暖湿化, 对喜温好水的双季稻生产是利大于弊; 而江南稻区则呈暖干化趋势, 对水稻生产不利; 同时秋旱风险加大, 尤其是西部地区将面临水资源减少、水稻种植用水不足。另一方面, 随着双季稻区气候变暖, 早稻适宜播种期提前、早晚稻生长季延长, 热量资源增加以及薄膜育秧技术广泛应用等, 都将使双季稻种植格局调整。双季稻区高温日数增多, 早晚稻生长发育无效热量也随之增加, 整体上江南热量资源的有效性低于华南, 尤其是江西和湖南两省, 热量有效性均 < 85%;华南大部地区热量有效性均高于95%。因而, 各地可根据所处区域气候资源要素演变规律及热量有效性分布选取产量与品质更好的中晚熟品种种植, 提高水稻种植积极性, 促进早晚稻安全生产。 

CHANGES OF CLIMATE RESOURCES IN THE DOUBLE-CROPPING RICE REGION IN SOUTH CHINA AND THEIR EFFECT DURING 1961-2010

The double-cropping rice area in south China is China''s major rice-producing area, where the planting area of rice accounts for more than 85% of the national total. In this paper, the evolution of climate resources and its possible influence on double-cropping rice in the south of the Yangtze River and south China were studied. The results showed that the study areas experienced significant temperature rise, especially since the 1997 temperature mutations which resulted in a further increase of warming rate; at the same time, the autumn and winter temperature increase was also more significant. There was a trend of less precipitation in spring and autumn, while more in summer and winter, making precipitation distribution more concentrated. Noticeable differences in the evolution of climate resources were found in the study areas, among which south China would be warm and wet, which was favorable to double-cropping rice production. However, the south of the Yangtze River showed a trend of warming and drying, which was unfavorable to rice production. At the same time, the risk of autumn drought increased, so especially the western region would face a reduction of water resources and rice planting water shortage. On the other hand, with climate warming, the advance of the suitable sowing date of early rice, the extension of the growth season of early and late rice, and the wide application of the thin film seedling technology would induce adjustment of the double-rice planting pattern. As the number of high temperature days increased in the double-rice area, the invalid heat during growth periods and development of early and late rice also increased. The thermal efficiency in most areas of south China was higher than 95%. Therefore, according to the evolution pattern of climatic resources and heat availability distribution in the region, the middle and late ripening varieties with better yield and quality can be selected to plant to improve the enthusiasm of rice planting and ensure the safe production of early and late rice.