Comparing three models to estimate transpiration of desert shrubs
Comparing three models to estimate transpiration of desert shrubs
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比较估计沙漠灌木蒸腾作用的三种模型
DOI：
10.1016/j.jhydrol.2017.05.027
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发表时间：
2017
影响因子：
6.4
通讯作者：
Sudicky Edward A.
中科院分区：
文献类型：
--
作者：
Xu Shiqin;Yu Zhongbo;Ji Xibin;Sudicky Edward A.
环境变量在控制蒸腾作用(EC)中的作用是干旱荒漠地区蒸腾作用模型的一个重要方面，但还没有得到很好的理解。以3种优势荒漠灌木梭梭、白刺和沙拐枣为例，研究了3种蒸腾模型：改进的Jarvis-Stewart模型(MJS)、基于过程的简化模型(BTA)和人工神经网络模型(ANN)在不同时间尺度上的适用性。在2014年和2015年的主要生长季，使用树干热平衡方法监测了每个物种的树干液流。同时使用自动气象站测量了同时存在的环境变量。与MJS和BTA模型相比，ANN模型在小时尺度和日尺度上对生态系统的模拟效果都要好，这表明它在解决蒸腾速率与环境驱动力之间复杂的非线性问题方面具有优势。太阳辐射和水汽压差是为这三个物种建立生态模型的关键变量。通过引入根区土壤水分，MJS和ANN模型的性能得到了显著改善。我们还发现，对于MJS和BTA模型，每小时和每天拟合的参数值之间的差异是相当大的。因此，当这些模型应用于不同的时间尺度时，需要重新校准。这项研究对现有蒸腾模型在干旱荒漠地区的应用和性能提供了见解，从而加深了对研究地点生态水文过程和可持续生态系统管理的理解。
The role of environmental variables in controlling transpiration (Ec) is an important, but not well-understood, aspect of transpiration modeling in arid desert regions. Taking three dominant desert shrubs,Haloxylon ammodendron,Nitraria tangutorum, andCalligonum mongolicum, as examples, we aim to evaluate the applicability of three transpiration models, i.e. the modified Jarvis-Stewart model (MJS), the simplified process-based model (BTA), and the artificial neural network model (ANN) at different temporal scales. The stem sap flow of each species was monitored using the stem heat balance approach over both the 2014 and 2015 main growing seasons. Concurrent environmental variables were also measured with an automatic weather station. The ANN model generally produced better simulations ofEcthan the MJS and BTA models at both hourly and daily scales, indicating its advantage in solving complicated, nonlinear problems between transpiration rate and environmental driving forces. The solar radiation and vapor pressure deficit were crucial variables in modelingEcfor all three species. The performance of the MJS and ANN models was significantly improved by incorporating root-zone soil moisture. We also found that the difference between hourly and daily fitted parameter values was considerable for the MJS and BTA models. Therefore, these models need to be recalibrated when applied at different temporal scales. This study provides insights regarding the application and performance of current transpiration models in arid desert regions, and thus provides a deeper understanding of eco-hydrological processes and sustainable ecosystem management at the study site.