基于SVAT模型的冬小麦光合作用和蒸散过程研究

在已建立的土壤－植被－大气传输（SVAT）模型中，冠层光合作用／气孔导度耦合子模型可区分遮荫叶和受光叶光合作用强度的差异；作物生长模型考虑了生长呼吸和维持呼吸，模拟与实测结果对比发现，日总蒸散量实测和模拟的根均方差（RMSD）为0.65mm，平均绝对差（MAPD）为14％；对冠层上部净光合作用率日变化过程而言，实测和模拟结果具有较好的一致性。利用模型模拟了冬小麦全生育争光合作用率和蒸散的演变过程。最后，分析了冬小麦蒸散和水分利用效率对不同最大叶面积指数，大气CO2浓度和叶片N含量的响应。

Simulating photosynthesis and evapotranspiration of winter wheat with a SVAT model

Two submodels were added to the developed soil vegetation atmosphere transfer model. Of the two sub models, one was the canopy photosynthesis/stomatal coupled sub model distinguishing the sun light and shaded leaves, and the second was the simplified growth sub model considering growth respiration and maintenance respiration. The comparison of measured and simulated daily evapotranspiration showed that the RMSD (root mean standard deviation) of model prediction to observation was 0.65 mm, and MAPD (mean absolute percent difference) was 14%. The daily course of the simulated and measured photosynthesis rates at the top of canopy were in good consistency. With the high resolution meteorological data, the canopy net photosynthesis and evapotranspiration were simulated over the whole growing season.The sensitivities of maximum leaf area index, environmental CO 2 concentration and leaf nitrogen content to evapotranspiration and water use efficiency were also analyzed.