Climate Change Data Portal
DOI | 10.5194/hess-22-3561-2018 |
Sensitivity and identifiability of hydraulic and geophysical parameters from streaming potential signals in unsaturated porous media | |
Younes A.; Zaouali J.; Lehmann F.; Fahs M. | |
发表日期 | 2018 |
ISSN | 1027-5606 |
起始页码 | 3561 |
结束页码 | 3574 |
卷号 | 22期号:7 |
英文摘要 | Fluid flow in a charged porous medium generates electric potentials called streaming potential (SP). The SP signal is related to both hydraulic and electrical properties of the soil. In this work, global sensitivity analysis (GSA) and parameter estimation procedures are performed to assess the influence of hydraulic and geophysical parameters on the SP signals and to investigate the identifiability of these parameters from SP measurements. Both procedures are applied to a synthetic column experiment involving a falling head infiltration phase followed by a drainage phase. GSA is used through variance-based sensitivity indices, calculated using sparse polynomial chaos expansion (PCE). To allow high PCE orders, we use an efficient sparse PCE algorithm which selects the best sparse PCE from a given data set using the Kashyap information criterion (KIC). Parameter identifiability is performed using two approaches: the Bayesian approach based on the Markov chain Monte Carlo (MCMC) method and the first-order approximation (FOA) approach based on the Levenberg-Marquardt algorithm. The comparison between both approaches allows us to check whether FOA can provide a reliable estimation of parameters and associated uncertainties for the highly nonlinear hydrogeophysical problem investigated. GSA results show that in short time periods, the saturated hydraulic conductivity (Ks) and the voltage coupling coefficient at saturation (Csat) are the most influential parameters, whereas in long time periods, the residual water content (θs), the Mualem-van Genuchten parameter (n) and the Archie saturation exponent (na) become influential, with strong interactions between them. The Mualem-van Genuchten parameter (α) has a very weak influence on the SP signals during the whole experiment. Results of parameter estimation show that although the studied problem is highly nonlinear, when several SP data collected at different altitudes inside the column are used to calibrate the model, all hydraulic (Ks, θs,α,n) and geophysical parameters (na,Csat) can be reasonably estimated from the SP measurements. Further, in this case, the FOA approach provides accurate estimations of both mean parameter values and uncertainty regions. Conversely, when the number of SP measurements used for the calibration is strongly reduced, the FOA approach yields accurate mean parameter values (in agreement with MCMC results) but inaccurate and even unphysical confidence intervals for parameters with large uncertainty regions. © 2018 Author(s). |
语种 | 英语 |
scopus关键词 | Approximation algorithms; Bayesian networks; Electric potential; Flow of fluids; Geophysics; Hydraulic conductivity; Markov processes; Media streaming; Monte Carlo methods; Porous materials; Sensitivity analysis; Uncertainty analysis; Estimation of parameters; First-order approximations; Global sensitivity analysis; Levenberg-Marquardt algorithm; Markov chain Monte Carlo method; Parameter identifiability; Saturated hydraulic conductivity; Variance-based sensitivity indices; Parameter estimation; Bayesian analysis; fluid flow; geophysical method; hydraulic conductivity; hydraulic head; identification method; infiltration; Monte Carlo analysis; nonlinearity; parameter estimation; porous medium; saturation; sensitivity analysis; unsaturated medium; variance analysis; water content |
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/159986 |
作者单位 | Younes, A., LHyGES, Université de Strasbourg/EOST/ENGEES, CNRS, 1 rue Blessig, Strasbourg, 67084, France, LISAH, Univ. Montpellier, INRA, IRD, SupAgro, Montpellier, France, LMHE, ENIT, Tunis, Tunisia; Zaouali, J., LHyGES, Université de Strasbourg/EOST/ENGEES, CNRS, 1 rue Blessig, Strasbourg, 67084, France; Lehmann, F., LHyGES, Université de Strasbourg/EOST/ENGEES, CNRS, 1 rue Blessig, Strasbourg, 67084, France; Fahs, M., LHyGES, Université de Strasbourg/EOST/ENGEES, CNRS, 1 rue Blessig, Strasbourg, 67084, France |
推荐引用方式 GB/T 7714 | Younes A.,Zaouali J.,Lehmann F.,et al. Sensitivity and identifiability of hydraulic and geophysical parameters from streaming potential signals in unsaturated porous media[J],2018,22(7). |
APA | Younes A.,Zaouali J.,Lehmann F.,&Fahs M..(2018).Sensitivity and identifiability of hydraulic and geophysical parameters from streaming potential signals in unsaturated porous media.Hydrology and Earth System Sciences,22(7). |
MLA | Younes A.,et al."Sensitivity and identifiability of hydraulic and geophysical parameters from streaming potential signals in unsaturated porous media".Hydrology and Earth System Sciences 22.7(2018). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。