TY  - JOUR
AU  - Li, L.
AU  - Zhou, H.
AU  - Hendricks-Franssen, H.J.
AU  - Gomez-Hernandez, J.
TI  - Modeling transient groundwater flow by coupling ensemble Kalman filtering and upscaling
JO  - Water resources research
VL  - 48
SN  - 0043-1397
CY  - Washington, DC
PB  - AGU
M1  - PreJuSER-20302
SP  - W01537
PY  - 2012
N1  - The authors acknowledge Wolfgang Nowak and three anonymous reviewers for their comments on the previous versions of the manuscript, which helped substantially to improve it. The authors gratefully acknowledge the financial support by the Spanish Ministry of Science and Innovation through project CGL2011-23295. Extra travel grants awarded to the first and second authors by the Ministry of Education (Spain) are also acknowledged. The second author also acknowledges financial support from the China Scholarship Council.
AB  - The ensemble Kalman filter (EnKF) is coupled with upscaling to build an aquifer model at a coarser scale than the scale at which the conditioning data (conductivity and piezometric head) had been taken for the purpose of inverse modeling. Building an aquifer model at the support scale of observations is most often impractical since this would imply numerical models with many millions of cells. If, in addition, an uncertainty analysis is required involving some kind of Monte Carlo approach, the task becomes impossible. For this reason, a methodology has been developed that will use the conductivity data at the scale at which they were collected to build a model at a (much) coarser scale suitable for the inverse modeling of groundwater flow and mass transport. It proceeds as follows: (1) Generate an ensemble of realizations of conductivities conditioned to the conductivity data at the same scale at which conductivities were collected. (2) Upscale each realization onto a coarse discretization; on these coarse realizations, conductivities will become tensorial in nature with arbitrary orientations of their principal components. (3) Apply the EnKF to the ensemble of coarse conductivity upscaled realizations in order to condition the realizations to the measured piezometric head data. The proposed approach addresses the problem of how to deal with tensorial parameters, at a coarse scale, in ensemble Kalman filtering while maintaining the conditioning to the fine-scale hydraulic conductivity measurements. We demonstrate our approach in the framework of a synthetic worth-of-data exercise, in which the relevance of conditioning to conductivities, piezometric heads, or both is analyzed.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000299702100001
DO  - DOI:10.1029/2010WR010214
UR  - https://juser.fz-juelich.de/record/20302
ER  -