华南地区早晚稻生育期降水特征分析

【目的】研究华南地区早稻和晚稻不同生育期间降水的特点,为华南双季稻种植提供决策依据,同时对华南地区双季稻生产和防灾减灾也具有积极意义。【方法】利用华南地区1960—2008年49年间逐日降水资料,计算早稻和晚稻不同生育期的区域平均累计降水和暴雨日平均百分率,分析降水多年平均值和空间分布特点。【结果】华南地区早稻和晚稻生育期总累计降水量相差不大,均在600 mm以上(早稻673.5 mm、晚稻611.5 mm)。早稻和晚稻各生育期累计降水量和日均降水量、日均暴雨降水量差异较大;生育期累计降水量最大为晚稻秧苗期(256.6 mm),最小为晚稻抽穗期(26.9 mm);早稻生育期日均降水量最大为结实期(8.2 mm)、最小为秧苗期(4.1 mm),晚稻最大为秧苗期(8.3 mm)、最小为结实期;早稻日均暴雨降水量随着生育期的后推逐渐增加,晚稻则随生育期的后推逐渐减少。空间分布表明,早稻和晚稻生育期内累计降水量和暴雨概率大值中心分布与华南地区前后汛期降水系统密切相关,早稻主要受到季风系统的影响,而晚稻受台风系统影响为主,降水和暴雨高值中心主要分布在沿海地区。【结论】早稻和晚稻不同生育期降水特征差异较大,早稻防涝工作应着重在结实期,晚稻防涝工作应重点在分蘖期。

Rainfall characteristics of growth duration of early and late rice in South China

Objective Rainfall characteristics during each growth period of early and late rice in South China region were studied to provide a decision-making basis and have an active meaning for double cropping rice production and disaster prevention and reduction in South China. Method Using daily precipitation data of 47 meteorology observational stations from 1960 to 2008 in South China, regional average cumulative precipitation and daily average percentage of rainstorm in each growth period of early and late rice were calculated, and annual average value and spatial distribution characteristic of rainfall were analyzed. Result There was almost the same accumulated rainfall with above 600 mm in early rice (673.5 mm) and late rice (611.5 mm)periods. The maximum accumulated rainfall occurred in seedling stage of late rice (256.6 mm), and the minimum value occurred in heading stage of late rice (26.9 mm). The maximum daily average precipitation in growth periods of early and late rice occurred in filling stage (8.2 mm) and seedling stage (8.3 mm) respectively, and the minimum value occurred in seedling stage (4.1 mm) and filling stage respectively. The daily average rainstorm and precipitation gradually increased with the growth stage for early rice, but decreased for late rice. The results of spatial distribution showed that the accumulated rainfall and frequency of heavy rainfall were closely related with the precipitation system in South China during the flood season. Early rice was mainly affected by the monsoon system,and late rice was mainly affected by the typhoon system. The high values of precipitation and rainstorm were mainly located in coastal areas. Conclusion Rainfall characteristics in the growth periods of early and late rice are different. The most important stage for preventing flood is filling stage for early rice, but tillering stage for late rice.