| 基于水碳通量耦合的长江中下游稻田蒸散发组分分解 |
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| 引用本文： | 刘博,汪文超,崔远来,徐涛.基于水碳通量耦合的长江中下游稻田蒸散发组分分解[J].农业工程学报,2021,37(24):94-101. |
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| 作者姓名： | 刘博 汪文超 崔远来 徐涛 |
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| 作者单位： | 1. 扬州大学水利科学与工程学院，扬州 225009；2. 武汉大学水资源与水电工程科学国家重点实验室，武汉 430072;3. 长江勘测规划设计研究有限责任公司，武汉 430010;4. 江西省灌溉试验中心站，南昌 330201 |
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| 基金项目： | 国家自然科学基金委员会-中华人民共和国水利部-中国长江三峡集团有限公司 长江水科学研究联合基金项目（U2040213）；江西省水利厅一般科技项目（202123YBKT09） |
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| 摘 要： | 探明稻田生态系统蒸散发（Evapotranspiration，ET）组分特征对于提高稻田水分利用效率、实现农业节水具有重要意义。该研究利用涡度相关（Eddy Covariance，EC）系统对长江中下游典型双季稻田水碳通量进行了连续2 a（2017 -2018年）的观测，使用潜在水分利用效率（Underlying Water Use Efficiency，uWUE）法将稻田ET分解为植株蒸腾（Transpiration，T）和棵间蒸发（Evaporation，E），揭示了稻田生态系统ET及其组分的季节变化特征，并使用小型蒸渗仪/涡度相关（Micro-lysimeter/Eddy Covariance, ML/EC）法观测结果对uWUE法进行了评估。结果表明：早晚稻植株蒸腾占蒸散发的比例（T/ET）均呈先增大后减少的趋势，水稻生育期T/ET在0.49～0.62之间，其中早稻季T/ET明显低于晚稻季。通过比较uWUE法和ML/EC法两种ET组分分解方法发现，uWUE法与ML/EC法估算T/ET差异主要在水稻生长前期和阴天；在其他时期，uWUE法和ML/EC法估算的T/ET显著线性相关（R2=0.852，P<0.01），表明uWUE法可以较好地模拟稻田ET组分。以上研究成果可为uWUE法在稻田生态系统的应用以及长江中下游稻田节水灌溉和水资源优化配置提供依据。
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| 关 键 词： | 蒸散发 蒸腾 蒸发 涡度相关技术 水碳通量耦合 稻田生态系统 潜在水分利用效率 |
| 收稿时间： | 2021/5/17 0:00:00 |
| 修稿时间： | 2021/10/10 0:00:00 |
Partitioning evapotranspiration using the water-carbon flux coupling in a paddy field in the Middle and Lower Reaches of the Yangtze River in China |
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| Liu Bo,Wang Wenchao,Cui Yuanlai,Xu Tao.Partitioning evapotranspiration using the water-carbon flux coupling in a paddy field in the Middle and Lower Reaches of the Yangtze River in China[J].Transactions of the Chinese Society of Agricultural Engineering,2021,37(24):94-101. |
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| Authors: | Liu Bo Wang Wenchao Cui Yuanlai Xu Tao |
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| Institution: | 1. College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou 225009, China; 2. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China;;3. Changjiang Survey, Planning, Design and Research Co., Ltd, Wuhan 430010, China; 4. Jiangxi Central Station of Irrigation Experiment, Nanchang 330201, China |
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| Abstract: | Abstract: Partitioning Evapotranspiration (ET) over an agricultural ecosystem has been one of the most important strategies to improve the water use efficiency of the rice-producing areas in the middle and lower reaches of the Yangtze River in China. However, the traditional ET partitioning presents labor intensive, scales mismatches, and low applicability. The new ET partitioning has been widely expected to consider the water-carbon fluxes coupling in recent years. In the present study, a two-year (2017-2018) water-carbon flux was evaluated using the eddy covariance measurement over a paddy field in the middle and lower reaches of the Yangtze River in China. An Underlying Water Use Efficiency (uWUE) model was also applied to partition the ET into the transpiration (T) and evaporation (E), in order to investigate the seasonal variation of ET and the E/T components. Moreover, the uWUE model was verified by the T/ET observation using the micro-lysimeter and eddy covariance measurement. The results showed that the ET were 318.4 and 335.6 mm for the early rice, and 451.9 and 469.0 mm for the late rice in 2017 and 2018, respectively. The seasonal variation of T/ET was also closely related to the plant phenology. Specifically, the E was the main component of ET with the T/ET ranging from 0.13-0.35 at the regreening stage after the early and late rice were transplanted. The T/ET gradually increased with the growth of the rice plant, when reaching the peak values of 0.62-0.79 at the jointing, booting-heading, and flowering stages. Then, the T/ET decreased with the senescence of the paddy rice. In season, the T/ET values of the early rice were 0.49 and 0.52, respectively, which were lower than those of the late rice (0.62 and 0.55) in 2017 and 2018, respectively, because the light and thermal conditions were much better during the late rice season. Furthermore, the T/ET variations over the paddy fields in the study area were close to those in the Sanjiang Plain, Philippines, Brazil, and Japan, but lower than the dryland ecosystems, such as wheat and maize. In addition, there were great differences in T/ET in the initial period and cloudy days using the uWUE and micro-lysimeter/eddy covariance measurements. The micro-lysimeter/eddy covariance measurement underestimated the T/ET in the early stage, whereas, the uWUE simulation overestimated in cloudy days. However, the daily T/ET presented a significant linear correlation (R2=0.852, P<0.01), indicating that the uWUE model can be used to partition ET over paddy fields. Future work needs to be done to investigate the water use efficiency over paddy fields in humid areas for better ET partitioning. The findings can also provide a strong reference for the application of uWUE model over rice ecosystems, as well as water-saving irrigation and allocation in the middle and lower reaches of the Yangtze River. |
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| Keywords: | evapotranspiration transpiration evaporation eddy covariance technology water-carbon fluxes coupling rice ecosystem underlying water use efficiency |
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