稻田CH4排放的农业气象数值模拟研究
NUMERICAL SIMULATION OF CH4 EMISSION FROM RICE PADDY FIELDS DURING RECENT 50 YEARS
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摘要: 在美国DNDC模式基础上, 综合气象学、农业气象学及生态学最新研究进展, 将作物生长、碳氮循环及CH4排放有机耦合, 建立了一个CH4排放数值模式, 模式通过了相关显著性检验。利用模式重点分析了气象因子对稻田CH4排放的影响状况, 数值分析表明, 当仅考虑气象条件影响时: (1) 不同地区不同生长季节的CH4排放量均与相应生长期的平均气温成正相关关系; (2) 功率谱分析表明稻田CH4排放存在4~5年周期变化, 与相应生长季节的平均温度年际变化规律相一致; (3) CH4排放量年际之间变化趋势与生长季平均气温变化趋势基本一致。利用数值计算结果, 给出了杭州及昌德地区早稻、晚稻CH4简易统计模式, 为应用模型监测并调控农田生态系统中的CH4排放奠定了基础。Abstract: Based on the DNDC model of American, a numerical model for simulating CH4 emission from rice paddy fields is established. Validation of the model with the observed data shows that the mean relative error is about 15%. The simulation analysis results show that the CH4 emission is interrelated well with average temperature during rice growth periods. Analysis of CH4 emission and meteorological factors by using power spectrum indicates that the change of CH4 emissions has 4-5 year cycles, which is the same as that of temperature. Simple statistical models are given based on the results of the numerical model, which can be applied conveniently to estimate and monitor CH4 emissions in the rice paddy fields.
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Key words:
- CH4 emissions;
- Rice paddy fields;
- Agrometeorological numerical model;
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表 1 稻田CH4排放量与相应生长期气象因子的相关系数
表 2 杭州地区早稻CH4排放与相应气象因子的功率谱分析
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