Back to Search
Start Over
A Linking Test to reduce the number of hydraulic parameters necessary to simulate groundwater recharge in unsaturated soils
- Source :
- Advances in Water Resources, Advances in Water Resources, Elsevier, 2008, 31 (2), pp.355 à 369. ⟨10.1016/j.advwatres.2007.09.002⟩
- Publication Year :
- 2008
- Publisher :
- HAL CCSD, 2008.
-
Abstract
- International audience; In environmental studies, numerical simulation models are valuable tools for testing hypothesis about systems functioning and to perform sensitivity studies under scenarios of land use or climate changes. The simulations depend upon parameters which are not always measurable quantities and must be calibrated against observations, using for instance inverse modelling. Due to the scarcity of these observations, it has been found that parameter sets allowing a good matching between simulated and measured quantities are often non-unique, leading to the problem of equifinality. This can lead to non-physical values, erroneous fluxes and misleading sensitivity analysis. Therefore, a simple but robust inverse method coined the Linking Test is presented to determine if the parameters are linked. Linked parameters are then sub-divided into classes according to their impact on water fluxes. The Linking Test establishes the causes of non-uniqueness of parameter sets and the feasibility of the inverse modelling. The Linking Test is applied to a one-dimensional soil-vegetation water flow model to predict groundwater recharge from the Richards' equation. Under the tested climates and by assuming the vegetation parameters constant, the Linking Test showed that only 2 parameters out of 6 Mualem-van Genuchten parameters are required to determine an accurate recharge for soils not reaching saturation. For a reference soil, the Linking Test enables to determine, all the different combinations of the parameters that give similar recharge. The parameter sets are obtained by optimising the parameters against time series of soil moisture profiles. The Linking Equations established for the reference soil have important implications for sensitivity analysis, upscaling and infiltration tests.
- Subjects :
- 010504 meteorology & atmospheric sciences
Water flow
[SDE.MCG]Environmental Sciences/Global Changes
Hydraulic parameters
0207 environmental engineering
Soil science
02 engineering and technology
Equifinality
01 natural sciences
Groundwater recharge
Inverse modelling
Geotechnical engineering
[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology
020701 environmental engineering
Water content
0105 earth and related environmental sciences
Water Science and Technology
Computer simulation
15. Life on land
6. Clean water
Linking Test
Infiltration (hydrology)
Richards' equation
13. Climate action
Unsaturated flow
Soil water
Environmental science
Richards equation
van Genuchten
Subjects
Details
- Language :
- English
- ISSN :
- 03091708
- Database :
- OpenAIRE
- Journal :
- Advances in Water Resources, Advances in Water Resources, Elsevier, 2008, 31 (2), pp.355 à 369. ⟨10.1016/j.advwatres.2007.09.002⟩
- Accession number :
- edsair.doi.dedup.....27439e3af1fb53b2c3376c2d69d46859