Evaluating three evapotranspiration methods in the SLURP macroscale hydrological model

• Published in: Hydrological processes 1997-10, Vol.11 (13), p.1685-1705
• Main Authors: Barr, Alan G., Kite, G. W., Granger, R., Smith, C.
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; evaluation; evapotranspiration models; Exact sciences and technology; Freshwater; hydrological model; Hydrology; Hydrology. Hydrogeology
• ISSN: 0885-6087; 1099-1085
• DOI: 10.1002/(SICI)1099-1085(19971030)11:13<1685::AID-HYP599>3.0.CO;2-T

Hydrological models simulate the land phase component of the global water cycle and provide a mechanism for evaluating the effects of climatic variation and change on water resources. Evapotranspiration (ET) is a critical process within such models. This study evaluates three different methods for estimating ET in the simple lumped reservoir parametric model (SLURP), over a five‐year period in the Kootenay Basin of eastern British Columbia. The three ET methods were the Morton implementation of the Bouchet complementary relationship, the Granger modification of Penman's method and the Spittlehouse energy‐limited versus soil moisture‐limited method. We evaluated the three ET methods indirectly, based on the ability of the SLURP hydrological model to simulate daily stream flow over several annual cycles. Although the ET methods affected simulated stream flow differently, the Spittlehouse method had more physical significance and gave better agreement between simulated and recorded stream flows. The results showed that using an ET method that included a soil moisture limitation to ET produced a worthwhile improvement in hydrological performance. © 1997 John Wiley & Sons, Ltd.