Improving estimation of evapotranspiration during soil freeze-thaw cycles by incorporating a freezing stress index and a coupled heat and water transfer model into the FAO Penman-Monteith model
Improving estimation of evapotranspiration during soil freeze-thaw cycles by incorporating a freezing stress index and a coupled heat and water transfer model into the FAO Penman-Monteith model
复制标题
通过将冻结应力指数和热水耦合传输模型纳入粮农组织 Penman-Monteith 模型，改进土壤冻融循环期间蒸散量的估算
DOI：
10.1016/j.agrformet.2019.107847
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发表时间：
2020-02
影响因子：
6.2
通讯作者：
Qiang Cheng
中科院分区：
文献类型：
--
作者：
Qiang Xu;Xiaofei Yan;David A. Grantz;Xu Zhang Xue;Yurui Sun;Peter Schulze Lammers;Zhongyi Wang;Qiang Cheng
蒸散量（ET）在地-气界面水分和能量平衡中起着重要作用。近地表土壤含水量（SWC）或土壤水势（SWP）是影响蒸散的重要参数，已被纳入FAO Penman-Monteith（FAO-PM）模型中用于作物生长季蒸散的预测。然而，在冬季土壤冻融循环过程中，SWC或SWP对ET预测的影响的信息很少。我们提出了一个实验，在一个示范农场与冬小麦作物，在两个冬天附近的北京，中国。利用配备有气象站的蒸渗仪系统测量了蒸散通量和气象数据。利用介质管传感器和数字温度传感器分别测量了未冻土壤含水量和土壤温度。SWP由实测的USWC和由土壤冻结特性（SFC）曲线和Clapeyron方程推导出的土壤水分特性（SMC）曲线确定。第1年的详细测量结果表明，FAO-PM模型表现出复杂的误差模式，低估了来自未冻土的ET，但高估了来自稳定冻土的ET。为了解决这些错误，我们定义了一个冻结应力指数（Ksf）作为SWP的函数。在FAO-PM模型中引入Ksfa作为标准作物系数的修正因子，改善了对ET的预测（第1年，RMSE从0.424下降到0.187 mm day−1）。这些数据揭示了土壤表层（<10 cm）SWP与冻融循环中测定的ET之间的相关性。在改进的FAO-PM模型中加入了一个耦合的热量和水分传输（CHWT）模型，以当前气象数据作为上边界条件，利用ET、USWC和Tsoilas初始条件的初始测量值以及第1年优化的Ksfand土壤水力学性质，预测第2年冬季的USWC、SWP和ET。结果表明，ET估计得到了显着改善，使用组合（FAOPM-Ksf-CHWT）模型，RMSE从0.323降至0.281 mm day− 1。模型误差主要来源于对土壤冻结过程SWP的低估。该组合模型将FAO-PM模型的实用性扩展到温带气候的非作物季节，包括冬季，并降低了间歇性冻土ET准确预测的数据要求。
Evapotranspiration (ET) plays an important role in water and energy balance at the surface-atmosphere interface. It is widely reported that near-surface soil water content (SWC) or soil water potential (SWP) significantly affects ET and this parameter has been incorporated into the FAO Penman-Monteith (FAO-PM) model for prediction of ET during crop growth seasons. However, there is little information on the effect of SWC or SWP on prediction of ET during soil freeze-thaw cycles in winter. We present an experiment conducted at a demonstration farm with a crop of winter wheat, over two winters near Beijing, China. A lysimeter system equipped with a weather station was used to measure the ET flux and meteorological data. Unfrozen soil water content (USWC) and soil temperature (Tsoil) were measured using dielectric tube sensors (DTS) and digital temperature sensors, respectively. SWP was determined by measured USWC and a soil moisture characteristic (SMC) curve derived from the soil freezing characteristic (SFC) curve and the Clapeyron equation in frozen soil. Detailed measurements in year 1 showed that the FAO-PM model exhibited a complex error pattern, underestimating ET from unfrozen soil but overestimating ET from stable frozen soil. To address these errors, we define a freezing stress index (Ksf) as a function of SWP. Incorporation ofKsfas a modifier of the standard crop coefficient in the FAO-PM model improved prediction of ET (RMSE declined from 0.424 to 0.187 mm day−1, in year 1). These data revealed a correlation between SWP near the soil surface (<10 cm) and measured ET over freezing and thawing cycles. We incorporated a coupled heat and water transfer (CHWT) model into the improved FAO-PM model to predict USWC, SWP and ET throughout the winter of year 2 from current meteorological data as upper boundary conditions, initial measurements of ET, USWC andTsoilas initial conditions, andKsfand soil hydraulic properties optimized in year 1. The results showed that ET estimation was significantly improved, with RMSE reduced from 0.323 to 0.281 mm day−1using the combined (FAOPM-Ksf-CHWT) model. Model error primarily derived from an underestimation of simulated SWP during soil freezing process. The combined model extends the utility of the FAO-PM model to non-cropping seasons including winter in temperate climates and reduces the data requirements for accurate prediction of ET from intermittently frozen soil.
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影响因子：
6.7
作者：
V. Phogat;J. Šimůnek;M. Skewes;J. Cox;M. Mccarthy
通讯作者：
V. Phogat;J. Šimůnek;M. Skewes;J. Cox;M. Mccarthy
影响因子：
6.7
作者：
M. Tomás-Burguera;S. Vicente‐Serrano;M. Grimalt;S. Beguerı́a
通讯作者：
M. Tomás-Burguera;S. Vicente‐Serrano;M. Grimalt;S. Beguerı́a
DOI：
10.1016/j.agwat.2010.10.012
发表时间：
2011-02
期刊：
Fuel and Energy Abstracts
影响因子：
--
作者：
A. Torres;W. Walker;M. McKee
通讯作者：
A. Torres;W. Walker;M. McKee
DOI：
10.2136/sssaj1998.03615995006200040007x
发表时间：
1998-07
影响因子：
2.9
作者：
J. Šimůnek;M. Genuchten;O. Wendroth
通讯作者：
J. Šimůnek;M. Genuchten;O. Wendroth
DOI：
10.13031/2013.31040
发表时间：
1989-03-01
期刊：
TRANSACTIONS OF THE ASAE
影响因子：
--
作者：
FLERCHINGER, GN;SAXTON, KE
通讯作者：
SAXTON, KE