Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2021, Vol. 57 ›› Issue (1): 162-172.DOI: 10.13209/j.0479-8023.2020.119

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Impact of Model Structure and Parameterization Differences on Evapotranspiration Estimation

ZHAO Wenli1, XIONG Yujiu2, QIU Guoyu1,†, YAN Chunhua1, ZOU Zhendong1, QIN Longjun1   

  1. 1. School of Environment and Energy, Peking University Shenzhen Graduate School, Peking University, Shenzhen 518055 2. School of Civil Engineering, Sun Yat-Sen University, Guangzhou 510275
  • Received:2020-01-14 Revised:2020-03-15 Online:2021-01-20 Published:2021-01-20
  • Contact: QIU Guoyu, E-mail: qiugy(at)pkusz.edu.cn

模型结构与参数化差异对蒸散发估算的影响

赵文利1, 熊育久2, 邱国玉1,†, 鄢春华1, 邹振东1, 秦龙君1   

  1. 1. 北京大学深圳研究生院环境与能源学院, 深圳 518055 2. 土木工程学院, 中山大学, 广州 510275
  • 通讯作者: 邱国玉, E-mail: qiugy(at)pkusz.edu.cn
  • 基金资助:
    深圳市知识创新计划(JCYJ20180504165440088)和国家自然科学基金(41671416)资助

Abstract:

Based on the HiWATER high-density eddy covariance (EC) tower observations in Heihe Oasis in 2012, the impact of model structure differences (comparison between one-source Penman-Monteith / PM equation and two-source PM equation, or comparison between two-source PM equation and two-source three-temperature model) and parameterization differences on the evapotranspiration estimation were evaluated. The results show that, 1) compared with the two-source PM equation with a relatively complex model structure, the mean absolute percent error (MAPE) estimated by the one-source PM equation is 34%, which is more accurate than that by the two-source PM equation (40%); 2) for two kinds of two-source model with significant differences in model structure, the three-temperature model without resistance parameters has higher estimation accuracy than the PM-based equation with resistance parameters. The former has a MAPE of 18% (R2=0.85), while the PM-based equation has that of 40% (R2=0.34); 3) two one-source and one two-source resistance parameterization methods lead to different evapotranspiration estimation accuracy for the PM-based equation, with a MAPE difference of up to 6%; 4) using prior knowledge / dataset to calibrate resistance parameterization can significantly improve the estimation accuracy of one-source PM equation (MAPE can be reduced by 22%), but as model structure and parameterization complexity increase, two-source PM equation hasn’t been improved significantly after resistance parameterization calibration (MAPE is only reduced by 0.8%).

Key words: evapotranspiration, Penman-Monteith, resistance, three-temperature model, HiWATER, Heihe

摘要:

基于2012年黑河绿洲HiWATER高密度通量观测数据, 对比研究模型结构差异(单源Penman-Monteith/PM公式与双源PM公式、双源PM 公式与双源三温模型)以及PM公式中阻抗参数化差异对蒸散发估算的影响。结果表明: 1) 与模型结构相对复杂的双源PM公式相比, 单源PM公式计算的蒸散发平均相对误差(MAPE)为34%, 略优于双源PM公式的40%; 2) 对于两种模型结构差异显著的双源模型, 模型中不含阻抗参数的三温模型比模型中含阻抗参数的PM公式具有更高的估算精度, 前者的MAPE为18% (R2=0.85), 后者为40% (R2=0.34); 3) 两种单源和一种双源阻抗参数化方法导致PM公式计算的蒸散发出现不同程度的差异, MAPE可相差6%; 4) 使用先验知识/数据事前率定阻抗参数化方法, 可显著地提高单源PM公式的计算精度(MAPE可降低22%), 但随着模型结构与参数化复杂度增加, 事前率定双源PM公式的阻抗参数化方法难以提高计算精度(MAPE仅减小0.8%)。

关键词: 蒸散发, Penman-Monteith, 阻抗, 三温模型, HiWATER, 黑河