Improvement of evapotranspiration simulation in a physically based ecohydrological model for the groundwater–soil–plant–atmosphere continuum
Improvement of evapotranspiration simulation in a physically based ecohydrological model for the groundwater–soil–plant–atmosphere continuum
复制标题
地下水-土壤-植物-大气连续体物理生态水文学模型中蒸散模拟的改进
DOI：
10.1016/j.jhydrol.2022.128440
复制
发表时间：
2022
影响因子：
6.4
通讯作者：
Shang Shasha
中科院分区：
文献类型：
--
作者：
Zhang Kun;Zhu Gaofeng;Ma Ning;Chen Huiling;Shang Shasha
陆地蒸散量的准确定量对于理解陆-气相互作用以及植被动态的反馈响应至关重要。在我们以前的工作中，一个基于物理的生态水文模型称为简单的陆地水圈（SiTH）模型估计ET和其他ET相关变量的基础上地下水-土壤-植物-大气连续体（GSPAC）。然而，SiTH模型（SiTHv 1）在模型结构和参数方面仍存在一些缺陷，这可能会导致陆地ET估计的潜在不确定性。在这项研究中，我们旨在通过开发一个新版本的SiTH模型（SiTHv 2）来解决这些限制。对SiTHv 2模式的主要改进包括：（1）利用植被光学厚度观测值更新植被水分约束模块;（2）利用通量观测值约束与根系分布相关的关键模型参数;（3）将土壤模块扩展为总深度为5 m的三层模块;（4）在农田区域采用灌溉输入水策略;（5）将土壤模型扩展为土壤模型。（5）采用最新的ERA 5-Land再分析资料作为气象强迫资料，并具有较好的空间分辨率。SiTHv 2模型的估计ET在多个尺度下进行验证/比较（即，站点/地块、流域和全球），分别与通量数据、流域水平衡数据和其他主流全球ET产品进行比较。结果表明，SiTHv 2模型的性能优于SiTHv 1模型，整体模型的均方根误差分别为0.66 mm day−1（地块尺度）和98.58 mm year−1（流域尺度），在相同情况下分别比SiTHv 1模型提高了27%和22%。此外，与现有的地面ET模型和产品相比，SiTHv 2模型的性能排名良好。SiTH模型的改进，应允许改进估计的陆地ET和提供支持，在GSPAC内的水转移的潜在研究。
Accurate quantification of terrestrial evapotranspiration (ET) is essential to understanding the interaction between land and atmosphere, as well as the feedback response of vegetation dynamics. In our previous work, a physically based ecohydrological model called the simple terrestrial hydrosphere (SiTH) model was developed to estimate ET and the other ET-related variables based on the groundwater–soil–plant–atmosphere continuum (GSPAC). However, the SiTH model (SiTHv1) still has some deficiencies in the model structure and parameters, which can result in potential uncertainty in the estimation of terrestrial ET. In this study, we aimed to address these limitations by developing a new version of the SiTH model (SiTHv2). The main modifications of the SiTHv2 model include: (1) the vegetation moisture constraint module is updated with vegetation optical depth observations; (2) the critical model parameters associated with root distribution are constrained using flux observations; (3) the soil module is extended to a three-layer module with 5 m of total depth; (4) an irrigation input water strategy is applied in the cropland areas; and (5) the latest ERA5-Land reanalysis data with a finer spatial resolution are used as the meteorological forcing data. The estimated ET of the SiTHv2 model was validated/compared at multiple scales (i.e., site/plot, basin, and global) with flux data, basin water balance data, and other mainstream global ET products, respectively. The results demonstrate that the SiTHv2 model performs better than the SiTHv1 model, with an improvement in the overall model root-mean-square error of 0.66 mm day−1 (plot scale) and 98.58 mm year−1 (basin scale), representing 27% and 22% improvements over the SiTHv1 model in the same circumstances, respectively. In addition, the performance of the SiTHv2 model ranks well when compared to the existing terrestrial ET models and products. The improvements to the SiTH model should allow improved estimation of terrestrial ET and provide support to potential studies in water transfer within the GSPAC.