不同坐标旋转方法对玉米地水热通量校正的影响  

Improving the Accuracy of Water and Thermal Fluxes Calculated for Maize Field Using Coordinate Rotation Method

作　　者：杨丹妮 陈岩 秦淑静 李思恩[1] YANG Danni;CHEN Yan;QIN Shujing;LI Sien(China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学,北京100083

出　　处：《灌溉排水学报》2018年第10期1-8,共8页Journal of Irrigation and Drainage

基　　金：水利部公益性行业科研专项经费项目(201501016);国家自然科学基金优秀青年科学基金项目(51622907)

摘　　要：【目的】提高涡度相关通量数据的能量闭合率,比较不同的坐标旋转法对水热通量校正的影响。【方法】采用二次坐标旋转法、三次坐标旋转法和平面拟合法,分别对涡度相关法测得的2015―2016年甘肃武威凉州区石羊河试验站制种玉米地的显热和潜热通量数据进行了分析。【结果】二次坐标旋转法和三次坐标旋转法对能量闭合率的提升效果相差不大,但经三次坐标旋转法处理后,湍流通量和有效能量数据的相关性更好。平面拟合法更适用于下垫面均匀平整、湍流交换较为稳定、平流作用较弱的环境,复杂地形条件下可选用分时段独立旋转法处理数据。当地试验条件下,涡度相关法观测得到的覆膜畦灌制种玉米地的能量闭合率比膜下滴灌制种玉米地的高5%~8%,对应的湍流通量均值高2%~17%,对应的湍流通量与有效能量的均方根误差低12%~23%。【结论】当地试验条件下,灌溉方式为覆膜畦灌时,适合采用平面拟合法对涡度相关水热通量进行仪器倾斜校正,而膜下滴灌时则更适合采用三次坐标旋转法。【Objective】The energy closure rate plays an important role in calculating water and thermal fluxes of farmland in using the eddy covariance data, and this paper investigated the efficacy of using coordinate rotation method to improve the accuracy of the fluxes calculated for a maize field.【Method】Latent heat and sensible heat fluxes were measured by the eddy covariance method in the Shiyang River Experimental Station at Wuwei City of Gansu Province from 2015 to 2016; they were then analyzed using the Double Rotation and Triple Rotation methods, as well as the Planar Fit method.【Result】There was no noticeable difference between the energy closure rates calculated by the Double Rotation and Triple Rotation methods, yet the correlation between the turbulent flux and the effective energy after incorporating the Triple Rotation method was improved. The Planar Fit method was more suitable for places where the underlying surface is uniformly flat, the turbulent exchange was stable and the advection was weak. In contrast, the Double Rotation and Triple Rotation methods worked better for complex terrains. In our experiment, the calculated energy closure rate of water and thermal fluxes for mulched maize field with border irrigation was higher than for mulched maize field with drip irrigation by 5%-8% and the mean turbulent flux was 2%-17% higher, with the root mean square error for the turbulent flux and effective energy in the former being 12% -23% lower than that in the latter.【Conclusion】In our experimental field, the Planar Fit method is appropriate to calculate the eddy-covariance water and thermal flux in terms of tilt correction for mulched field with border irrigation, while the Triple Rotation method works better for mulched field with drip irrigation.

关 键 词：涡度相关 能量闭合率 二次坐标旋转法 三次坐标旋转法 平面拟合法 

分 类 号：S513[农业科学—作物学]