机构地区:[1]湖北省水电工程智能视觉监测重点实验室(三峡大学),湖北宜昌443002 [2]水电工程智能视觉监测宜昌市重点实验室(三峡大学),湖北宜昌443002 [3]三峡大学水利与环境学院,湖北宜昌443002 [4]三峡库区生态环境教育部工程研究中心,湖北宜昌443002 [5]中国科学院青藏高原研究所青藏高原地球系统与资源环境重点实验室,北京100101
出 处:《灌溉排水学报》2023年第12期15-21,共7页Journal of Irrigation and Drainage
基 金:水电工程智能视觉监测湖北省重点实验室建设(2019ZYYD007);2020年度水电工程智能视觉监测湖北省重点实验室(三峡大学)开放基金重点项目(2020SDSJ03);湖北省教育厅科学技术研究项目(Q20221209);第二次青藏高原科学考察与研究项目(2019QZKK0103)。
摘 要:【目的】利用修正Penman-Monteith(PM)模型对土壤水分胁迫条件下的柑橘树蒸腾速率进行模拟。【方法】基于2022年6—7月的气象数据、红外温度、叶片气孔导度及实测柑橘树蒸腾速率,对PM模型中的关键参数(冠层阻力和空气动力学阻力)进行模拟。采用Ortega-Farias模型模拟冠层阻力;采用Perrier对数法和仿叶法分别计算空气动力学阻力,将模拟的阻力参数应用于PM模型,模拟柑橘树在不同土壤水分胁迫条件下的蒸腾速率,评价不同阻力参数对PM模型输出精度的影响。【结果】柑橘树气孔导度和蒸腾速率随着土壤水分胁迫程度的增大呈下降趋势。Ortega-Farias模型模拟的冠层阻力与实测值具有较好的一致性,模拟值与实测值之间的决定系数(R2)为0.63,能够较好地反映柑橘树叶片冠层阻力在水分胁迫下的日变化情况。在模拟空气动力学阻力时,仿叶法的模拟值大于Perrier对数法的模拟值,且午时波动较大。在土壤水分充足、轻度土壤水分胁迫、中度土壤水分胁迫和重度土壤水分胁迫条件下,采用Perrier对数法计算空气动力学阻力时,PM模型的模拟值与实测值之间的R2分别为0.66、0.58、0.55、0.2;而采用仿叶法计算空气动力学阻力时,PM模型的模拟值与实测值之间的R2分别为0.71、0.64、0.62、0.24。【结论】当土壤含水率高于田间持水率的50%时,使用Ortega-Farias模型模拟冠层阻力并采用仿叶法模拟空气动力学阻力能够提升PM模型模拟柑橘树蒸腾速率的精度。【Objective】Transpiration is not only an important hydrological process but also a footprint of primary productivity of terrestrial systems under different environments.Its calculation at large scale is challenging.This paper proposes a method to fill this gap.【Method】The method is based on the modified Penman-Monteith(PM)model.The canopy resistance in the model is estimated using soil moisture based on the Ortega-Farias model,and the hydrodynamic resistance is calculated by two methods:one is based on wind speed and canopy temperatureenvironment relationship,and the other one is the Perrier logarithm method.The model was applied to simulate transpiration of citrus trees under water stress from June to July in 2022;its accuracy was evaluated against groundtrue data.【Result】Water stress significantly reduced stomatal conductance and transpiration of the citrus trees.The canopy resistance estimated by the Ortega-Farias model agreed with the measured data with R^(2)=0.63,accurately capturing the diurnal variation in canopy resistance under water stress.The aerodynamic resistance calculated by the leaf-based method was significantly greater than estimated by the Perrier logarithmic method.The accuracy of aerodynamic resistance calculated by the Perrier logarithmic method varied with soil water content,and the R^(2)between the measured and calculated transpiration from the PM model decreased from 0.66 when the plant was under slight water stress to 0.2 when the plant was under severe stress.In contrast,for the transpiration calculated using the aerodynamic resistances estimated by the leaf-simulation method,the R^(2)decreased from 0.71 to 0.24 with the increase in water stress.【Conclusion】When the soil moisture was greater than 50%of the field capacity,using the Ortega-Farias model to estimate canopy resistance and the leaf-based method to estimate aerodynamic resistance can improve the accuracy of the PM model for simulating transpiration of the citrus trees under water stress.
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