Evaluation of evapotranspiration methods for model validation in a semi-arid watershed in northern China
Evaluation of evapotranspiration methods for model validation in a semi-arid watershed in northern China
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DOI：
10.5194/adgeo-11-37-2007
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发表时间：
2007-05
影响因子：
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通讯作者：
K. Schneider;B. Ketzer;L. Breuer;K. Vaché;C. Bernhofer;H. Frede
中科院分区：
文献类型：
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作者：
K. Schneider;B. Ketzer;L. Breuer;K. Vaché;C. Bernhofer;H. Frede
抽象的。本研究评价了四种不同复杂性的蒸散方法(Priestley-Taylor、Penman-Monteith、Hargreaves和Makkink)在中国北部半干旱环境中的应用效果。将结果与由涡流通量测量得到的观测水汽通量进行了比较。在使用土壤和水评估工具(SWAT)的自动校准版本的流量模拟未能再现径流测量结果后，这一分析变得必要。尽管研究区的大部分年降雨量都在植被时期，但高温会导致缺水。我们研究了哪种蒸散方法最适合这种环境，以及是否可以用最合适的蒸散方法来改善SWAT的模型性能。连续两年在不同降雨量下对蒸散量模型进行检验。总体而言，简单的Hargreaves和Makkink方程优于复杂的Priestley-Taylor和Penman-Monteith方法，尽管它们的性能取决于水的可用性。然而，对SWAT径流模拟质量的影响仍然很小。尽管蒸散是草原环境水文学中的一个重要过程，但我们的分析表明，仍需要确定其他驱动因素来改进SWAT模拟。
Abstract. This study evaluates the performance of four evapotranspiration methods (Priestley-Taylor, Penman-Monteith, Hargreaves and Makkink) of differing complexity in a semi-arid environment in north China. The results are compared to observed water vapour fluxes derived from eddy flux measurements. The analysis became necessary after discharge simulations using an automatically calibrated version of the Soil and Water Assessment Tool (SWAT) failed to reproduce runoff measurements. Although the study area receives most of the annual rainfall during the vegetation period, high temperatures can cause water scarcity. We investigate which evapotranspiration method is most suitable for this environment and whether the model performance of SWAT can be improved with the most adequate evapotranspiration method. The evapotranspiration models were tested in two consecutive years with different rainfall amounts. In general, the simple Hargreaves and Makkink equations outmatch the more complex Priestley-Taylor and Penman-Monteith methods, although their performance depended on water availability. Effects on the quality of SWAT runoff simulations, however, remained minor. Although evapotranspiration is an important process in the hydrology of this steppe environment, our analysis indicates that other driving factors still need to be identified to improve SWAT simulations.