气候变化领域集成服务门户(CCPortal): Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model

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DOI	10.5194/tc-8-257-2014
	Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model
	Wever N.; Fierz C.; Mitterer C.; Hirashima H.; Lehning M.
发表日期	2014
ISSN	19940416
卷号	8 期号:1
英文摘要	The runoff from a snow cover during spring snowmelt or rain-on-snow events is an important factor in the hydrological cycle. In this study, three water balance schemes for the 1 dimensional physically-based snowpack model SNOWPACK are compared to lysimeter measurements at two alpine sites with a seasonal snow cover, but with different climatological conditions: Weissfluhjoch (WFJ) and Col de Porte (CDP). The studied period consists of 14 and 17 yr, respectively. The schemes include a simple bucket-type approach, an approximation of Richards Equation (RE), and the full RE. The results show that daily sums of snowpack runoff are strongly related to a positive energy balance of the snow cover and therefore, all water balance schemes show very similar performance in terms of Nash-Sutcliffe efficiency (NSE) coefficients (around 0.63 and 0.72 for WFJ and CDP, respectively) and 2 values (around 0.83 and 0.72 for WFJ and CDP, respectively). An analysis of the runoff dynamics over the season showed that the bucket-type and approximated RE scheme release meltwater slower than in the measurements, whereas RE provides a better agreement. Overall, solving RE for the snow cover yields the best agreement between modelled and measured snowpack runoff, but differences between the schemes are small. On sub-daily time scales, the water balance schemes behave very differently. In that case, solving RE provides the highest agreement between modelled and measured snowpack runoff in terms of NSE coefficient (around 0.48 at both sites). At WFJ, the other water balance schemes loose most predictive power, whereas at CDP, the bucket-type scheme has an NSE coefficient of 0.39. The shallower and less stratified snowpack at CDP likely reduces the differences between the water balance schemes. Accordingly, it can be concluded that solving RE for the snow cover improves several aspects of modelling snow cover runoff, especially for deep, sub-freezing snow covers and in particular on the sub-daily time scales. The additional computational cost was found to be in the order of a factor of 1.5-2.
学科领域	alpine environment; energy balance; hydrological cycle; meltwater; Richards equation; runoff; snow cover; snowpack; water budget
语种	英语
scopus关键词	alpine environment; energy balance; hydrological cycle; meltwater; Richards equation; runoff; snow cover; snowpack; water budget
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120154
作者单位	WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260 Davos Dorf, Switzerland; Snow and Ice Research Center, NIED, Japan; CRYOS, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
推荐引用方式 GB/T 7714	Wever N.,Fierz C.,Mitterer C.,et al. Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model[J],2014,8(1).
APA	Wever N.,Fierz C.,Mitterer C.,Hirashima H.,&Lehning M..(2014).Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model.Cryosphere,8(1).
MLA	Wever N.,et al."Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model".Cryosphere 8.1(2014).