Abstract: Three hypothesis involving increase in climate variability（CV) in future (no change, 10% increase and 20% increase) were made, with which and outputs of the three GCMs (GISS, GFDL and UKMO), combined with the local Baseline weather at 19 sites in the middle and lower valley of the Yangtze River, China, 9 doubled CO2 climate change scenarios with CV consideration were generated using the weather generator(WGEN) in the DecisionSupport System for Agriculture Transfer (DSSAT) at each site. The genetic parameters of the CERESRice were modified using the Try and Error method and then calibrated and validated to examine its suitability in the studied regions, adopting the local statistical yield data (1979-1998)，combined with the local rice ecological experiments or regional varietal trials, as well as the synchronous meteorological and soil data at each site. Finally, the CERESRice was run again under the 9 scenarios and the Baseline, combined with the computation of evapotranspiration ratio (β) and the fluctuation coefficient, the effects of both climate change and its variability (CC+ΔCV) on rice production were assessed. The main results of this study were as follows: when CO2 doubled, with increase of CV, the heat damage induced by high temperature would become increasingly acute for different patterns of rice cropping systems in the studied regions, meanwhile, the low temperature stress would be significantly weakened for both early and late rice; There might be no obvious change in moisture conditions during rice growing season, but the probabilities occurring seasonal drought and rainstorm would increase; Rice growth duration under different cropping systems or irrigation patterns in the studied regions would be significantly shortened, however, ΔCV exerted no effect on rice growth duration; The simulated yields of both single and doublecropping rice, including irrigated and rainfed rice would be obviously reduced under the CC+ΔCV scenarios, compared with that under the CC scenarios and the yield reduction in the middle valley would be greater than that in the lower valley of the Yangtze River, singlecropping and late rice would be more significant than early rice and decreasing yield under the UKMO and GISS scenarios would be more serious than that under the GFDL scenario; With increasing ΔCV, not only the simulated yields further decreased compared with the control (ΔCV=0%), but also the yield stability reduced, indicating that the yield fluctuation coefficient would increase, however, perfect irrigation conditions would mitigate the yield fluctuations differing in years.

Key words: rice production, climate change, climatic variability, air carbon dioxide enrichment, simulation model

摘要： 在长江中下游稻区选择19个样点，将每个样点近20年（1979-1998年）的水稻产量资料及同期气象资料分为两组，一组结合当地水稻生态试验或品种区域试验资料用于CERESRice模型中遗传参数的调试，另一组用于检验该模型在研究区域的适用性。通过对未来气候变率变化(ΔCV)的3种假设并利用WGEN(天气生成器)，将每个样点基于3种平衡GCM(大气环流模型)的CO2倍增气候变化情景文件改进为兼顾气候及其变率变化(CC+ΔCV)的9种情景文件。在上述各情景文件下分别运行CERESRice，并将模拟结果与本底气候 (Baseline)下的模拟值进行比较，再结合蒸散比（β）和产量波动系数等算法，评价了CO2有效倍增时CC+ΔCV对长江中下游稻区水稻生产的影响。结果表明，当CO2有效倍增时，随着ΔCV的增大，不同稻作制度下水稻高温热害将愈演愈烈，早稻和晚稻受低温威胁将显著减轻；水稻生长季内干湿状况较目前无明显差异，但季节性干旱和暴雨的发生频次呈增加之势；研究区域不同稻作制度下的水稻生育期均明显缩短，ΔCV增大对生育期无显著影响；不论是单、双季稻，还是灌溉或雨育水稻都显著减产，其中中游稻区的减产幅度大于下游稻区，单季稻和晚稻的减产幅度大于早稻，UKMO、GISS情景下的减产幅度大于GFDL情景；研究区域不同稻作制度下的水稻进一步减产，且稳产性变差，但良好的灌溉条件可以减缓水稻产量的年际波动。

关键词: 水稻生产, 气候变化, 气候变率变化, 大气二氧化碳浓度升高, 模拟模型