Details
| Original language | English |
|---|---|
| Pages (from-to) | 334-340 |
| Number of pages | 7 |
| Journal | Hydrological processes |
| Volume | 30 |
| Issue number | 2 |
| Publication status | Published - 15 Jan 2016 |
Abstract
Although the importance to account for microrelief in the calculation of specific yields for shallow groundwater systems is well recognized, the microrelief influence is often treated very simplified, which can cause considerable errors. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total specific yield that is composed of the soil and surface specific yield. The one-dimensional expression can be applied for different soil hydraulic parameterizations and soil surface elevation frequency distributions. Applying different van Genuchten parameters and a simple linear microrelief model, we demonstrate that the specific yield is influenced by the microrelief not only when surface storage directly contributes to specific yield by (partial) inundation but also when water levels are lower than the minimum surface elevation. Compared with a simplified representation of the soil specific yield, in which a mean soil surface is assumed for the calculation of soil specific yield, the correct representation can lead to lower as well as higher soil specific yields depending on the specific interaction of the soil water retention characteristics and the microrelief. The new equation can be used to obtain more accurate evapotranspiration estimates from water level fluctuations and to account for the effect of microtopographic subgrid variability on simulated water levels of spatially distributed hydrological models.
Keywords
- Microrelief, Specific yield, Surface storage, Van genuchten, Water table fluctuation
ASJC Scopus subject areas
- Environmental Science(all)
- Water Science and Technology
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Hydrological processes, Vol. 30, No. 2, 15.01.2016, p. 334-340.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - One-dimensional expression to calculate specific yield for shallow groundwater systems with microrelief
AU - Dettmann, Ullrich
AU - Bechtold, Michel
N1 - Publisher Copyright: © 2016 John Wiley & Sons, Ltd. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2016/1/15
Y1 - 2016/1/15
N2 - Although the importance to account for microrelief in the calculation of specific yields for shallow groundwater systems is well recognized, the microrelief influence is often treated very simplified, which can cause considerable errors. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total specific yield that is composed of the soil and surface specific yield. The one-dimensional expression can be applied for different soil hydraulic parameterizations and soil surface elevation frequency distributions. Applying different van Genuchten parameters and a simple linear microrelief model, we demonstrate that the specific yield is influenced by the microrelief not only when surface storage directly contributes to specific yield by (partial) inundation but also when water levels are lower than the minimum surface elevation. Compared with a simplified representation of the soil specific yield, in which a mean soil surface is assumed for the calculation of soil specific yield, the correct representation can lead to lower as well as higher soil specific yields depending on the specific interaction of the soil water retention characteristics and the microrelief. The new equation can be used to obtain more accurate evapotranspiration estimates from water level fluctuations and to account for the effect of microtopographic subgrid variability on simulated water levels of spatially distributed hydrological models.
AB - Although the importance to account for microrelief in the calculation of specific yields for shallow groundwater systems is well recognized, the microrelief influence is often treated very simplified, which can cause considerable errors. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total specific yield that is composed of the soil and surface specific yield. The one-dimensional expression can be applied for different soil hydraulic parameterizations and soil surface elevation frequency distributions. Applying different van Genuchten parameters and a simple linear microrelief model, we demonstrate that the specific yield is influenced by the microrelief not only when surface storage directly contributes to specific yield by (partial) inundation but also when water levels are lower than the minimum surface elevation. Compared with a simplified representation of the soil specific yield, in which a mean soil surface is assumed for the calculation of soil specific yield, the correct representation can lead to lower as well as higher soil specific yields depending on the specific interaction of the soil water retention characteristics and the microrelief. The new equation can be used to obtain more accurate evapotranspiration estimates from water level fluctuations and to account for the effect of microtopographic subgrid variability on simulated water levels of spatially distributed hydrological models.
KW - Microrelief
KW - Specific yield
KW - Surface storage
KW - Van genuchten
KW - Water table fluctuation
UR - http://www.scopus.com/inward/record.url?scp=84955209814&partnerID=8YFLogxK
U2 - 10.1002/hyp.10637
DO - 10.1002/hyp.10637
M3 - Article
AN - SCOPUS:84955209814
VL - 30
SP - 334
EP - 340
JO - Hydrological processes
JF - Hydrological processes
SN - 0885-6087
IS - 2
ER -