Scholarlink

<p>Straw mulching significantly alters surface energy and water distribution, posing challenges for accurate evapotranspiration (<i>ET</i>) simulation. The original Shuttleworth-Wallace (SW) model often yields inaccurate <i>ET</i> estimates because it neglects the physical vapor barrier created by mulch. To address this limitation, we introduced a straw resistance term (<i>r</i><sub>straw</sub>) into the SW model framework and developed an improved model (SW<sub>straw</sub>) for straw-mulched farmland. Utilizing field measured data from summer maize fields in Northwest China during 2023−2024, with a straw mulch rate of 6000&#xa0;kg&#xa0;ha<sup>−1</sup>, we determined the <i>r</i><sub>straw</sub> to modify the soil surface evaporation resistance of the original SW model. Results demonstrated that while both models slightly overestimated water fluxes, SW<sub>straw</sub> significantly improved simulation accuracy. Compared to the original SW model, SW<sub>straw</sub> reduced total <i>ET</i> bias from 16.08−19.04 to 6.39−9.38%. The improvement was most pronounced during the seedling-to-tasseling stages, during which the normalized root mean square error (nRMSE) for soil evaporation (<i>E</i>) decreased by 22.22−61.54%. Specifically, SWstraw corrected the severe overestimation of <i>E</i> by accounting for the additional surface resistance provided by the straw layer, enhancing <i>E</i> simulation accuracy by 61.54% during the seedling stage. Path analysis revealed shifting regulatory mechanisms: under dense canopy conditions (<i>LAI</i> &gt; 2), net radiation (<i>R</i><sub><i>n</i></sub>) dominated <i>ET</i> partitioning by regulating both E and transpiration (<i>T</i>). Conversely, in sparse canopy stages (<i>LAI</i> &lt; 2), <i>E</i> was the primary determinant of the <i>E/ET</i> ratio, with <i>LAI</i> and Rn exerting indirect influence through their impacts on <i>E</i>. The present study advances the theoretical framework for <i>ET</i> modeling in straw-mulched farmland by developing an improved Shuttleworth-Wallace model that explicitly accounts for straw mulching effects. By quantifying the impact of straw mulching on surface resistance and evaporation processes, this research provides both a practical tool for precision agriculture and theoretical support for sustainable water-saving strategies in arid and semi-arid farmlands.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

An improved Shuttleworth-Wallace model for simulation of evapotranspiration and its components in straw-mulched maize fields

  • 期刊论文

  • 发表日期：

    2026年6月19日

查看全文
  • Yuyu Tian,
  • Xiaobo Gu,
  • Wenlong Li,
  • Yuanling Zhang,
  • Yunhui Niu,
  • Yadan Du,
  • Huanjie Cai,
  • Shikun Sun

摘要

Straw mulching significantly alters surface energy and water distribution, posing challenges for accurate evapotranspiration (ET) simulation. The original Shuttleworth-Wallace (SW) model often yields inaccurate ET estimates because it neglects the physical vapor barrier created by mulch. To address this limitation, we introduced a straw resistance term (rstraw) into the SW model framework and developed an improved model (SWstraw) for straw-mulched farmland. Utilizing field measured data from summer maize fields in Northwest China during 2023−2024, with a straw mulch rate of 6000 kg ha−1, we determined the rstraw to modify the soil surface evaporation resistance of the original SW model. Results demonstrated that while both models slightly overestimated water fluxes, SWstraw significantly improved simulation accuracy. Compared to the original SW model, SWstraw reduced total ET bias from 16.08−19.04 to 6.39−9.38%. The improvement was most pronounced during the seedling-to-tasseling stages, during which the normalized root mean square error (nRMSE) for soil evaporation (E) decreased by 22.22−61.54%. Specifically, SWstraw corrected the severe overestimation of E by accounting for the additional surface resistance provided by the straw layer, enhancing E simulation accuracy by 61.54% during the seedling stage. Path analysis revealed shifting regulatory mechanisms: under dense canopy conditions (LAI > 2), net radiation (Rn) dominated ET partitioning by regulating both E and transpiration (T). Conversely, in sparse canopy stages (LAI < 2), E was the primary determinant of the E/ET ratio, with LAI and Rn exerting indirect influence through their impacts on E. The present study advances the theoretical framework for ET modeling in straw-mulched farmland by developing an improved Shuttleworth-Wallace model that explicitly accounts for straw mulching effects. By quantifying the impact of straw mulching on surface resistance and evaporation processes, this research provides both a practical tool for precision agriculture and theoretical support for sustainable water-saving strategies in arid and semi-arid farmlands.