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| DOI：10.13522/j.cnki.ggps.2017.0733 |
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| Effects of Different Average Periods in Eddy Covariance on Calculation of Heat and Water Fluxes in Maize Field in Arid Region |
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LI Jia, CHEN Yan, QIN Shujing, LI Sien
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China Agricultural University, Beijing 100083, China
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| Abstract: |
| 【Objective】 The accuracy of the eddy covariance is affected by various factors and the objective of this paper is to study of the impact of average period on water and heat fluxes in a maize field in arid region. 【Method】 The Loggernet software was used to analyze the 10 Hz eddy covariance data measured from a seedling corn field at Hexi Corridor of Gansu Province in July 2015 with the average period set at 1, 2, 5, 10, 15, 30, 60, 120, 180, 360 and 720 min. The data obtained from the segmentation were used to calculate the energy flux in the corresponding period, and we then analyzed the effects of different average periods on the calculated energy flux from the field under different irrigation methods. 【Result】When the average period was less than 30 min, the change in average period only affected the value of daily flux data. The smaller the average period was, the smaller the energy flux was. When the average period was within 30~180 min, the change in the average cycle had a great impact on the calculated fluxes. During the rising period of the fluxes, the energy flux decreased as the average period increased. With flux declining, increasing the average period led to an increase in the fluxes. When the average period was 360 min and 720 min, there was noticeable error in the calculated energy flux. 【Conclusion】Average period in 15~60 min appeared to be most appropriate for calculating water and heat fluxes from the corn field in the arid region. |
| Key words: eddy covariance; average period; energy flux |
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