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DOI	10.5194/hess-24-2895-2020
	On the shape of forward transit time distributions in low-order catchments
	Heidbüchel I.; Yang J.; Musolff A.; Troch P.; Ferré T.; Fleckenstein J.H.
发表日期	2020
ISSN	1027-5606
起始页码	2895
结束页码	2920
卷号	24 期号:6
英文摘要	Transit time distributions (TTDs) integrate information on timing, amount, storage, mixing and flow paths of water and thus characterize hydrologic and hydrochemical catchment response unlike any other descriptor. Here, we simulate the shape of TTDs in an idealized low-order catchment and investigate whether it changes systematically with certain catchment and climate properties. To this end, we used a physically based, spatially explicit 3-D model, injected tracer with a precipitation event and recorded the resulting forward TTDs at the outlet of a small (ĝˆ1/46000 m2) catchment for different scenarios. We found that the TTDs can be subdivided into four parts: (1) early part - controlled by soil hydraulic conductivity and antecedent soil moisture content, (2) middle part - a transition zone with no clear pattern or control, (3) later part - influenced by soil hydraulic conductivity and subsequent precipitation amount, and (4) very late tail of the breakthrough curve - governed by bedrock hydraulic conductivity. The modeled TTD shapes can be predicted using a dimensionless number: higher initial peaks are observed if the inflow of water to a catchment is not equal to its capacity to discharge water via subsurface flow paths, and lower initial peaks are connected to increasing available storage. In most cases the modeled TTDs were humped with nonzero initial values and varying weights of the tails. Therefore, none of the best-fit theoretical probability functions could describe the entire TTD shape exactly. Still, we found that generally gamma and log-normal distributions work better for scenarios of low and high soil hydraulic conductivity, respectively. © 2020 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	Hydraulic conductivity; Normal distribution; Runoff; Soil moisture; Antecedent soil moisture; Dimensionless number; Forward transit time; Log-normal distribution; Precipitation events; Probability functions; Soil hydraulic conductivity; Transit-time distributions; Catchments; bedrock; breakthrough curve; catchment; hydraulic conductivity; precipitation (climatology); soil moisture; subsurface flow; tracer; transition zone
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159384
作者单位	Heidbüchel, I., Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, 04318, Germany; Yang, J., Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, 04318, Germany; Musolff, A., Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, 04318, Germany; Troch, P., Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, 85721, United States; Ferré, T., Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, 85721, United States; Fleckenstein, J.H., Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, 04318, Germany
推荐引用方式 GB/T 7714	Heidbüchel I.,Yang J.,Musolff A.,et al. On the shape of forward transit time distributions in low-order catchments[J],2020,24(6).
APA	Heidbüchel I.,Yang J.,Musolff A.,Troch P.,Ferré T.,&Fleckenstein J.H..(2020).On the shape of forward transit time distributions in low-order catchments.Hydrology and Earth System Sciences,24(6).
MLA	Heidbüchel I.,et al."On the shape of forward transit time distributions in low-order catchments".Hydrology and Earth System Sciences 24.6(2020).