Abstract
A simulator for 2D stochastic continuum simulation and inverse modelling of groundwater flow has been developed. The simulator is well suited for method evaluation and what-if simulation and written in MATLAB. Conductivity fields are generated by unconditional simulation, conditional simulation on measured conductivities and calibration on both steady-state head measurements and transient head histories. The fields can also include fracture zones and zones with different mean conductivities. Statistics of conductivity fields and particle travel times are recorded in Monte-Carlo simulations. The calibration uses the pilot point technique, an inverse technique proposed by RamaRao and LaVenue. Several Kriging procedures are implemented, among others Kriging neighborhoods. In cases where the expectation of the log-conductivity in the truth field is known the nonbias conditions can be omitted, which will make the variance in the conditionally simulated conductivity fields smaller. A simulation experiment, resembling the initial stages of a site investigation and devised in collaboration with SKB, is performed and interpreted. The results obtained in the present study show less uncertainty than in our preceding study. This is mainly due to the modification of the Kriging procedure but also to the use of more data. Still the large uncertainty in cases of sparse data
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Citation Formats
Eriksson, L O, and Oppelstrup, J.
Calibration with respect to hydraulic head measurements in stochastic simulation of groundwater flow - a numerical experiment using MATLAB.
Sweden: N. p.,
1994.
Web.
Eriksson, L O, & Oppelstrup, J.
Calibration with respect to hydraulic head measurements in stochastic simulation of groundwater flow - a numerical experiment using MATLAB.
Sweden.
Eriksson, L O, and Oppelstrup, J.
1994.
"Calibration with respect to hydraulic head measurements in stochastic simulation of groundwater flow - a numerical experiment using MATLAB."
Sweden.
@misc{etde_50355,
title = {Calibration with respect to hydraulic head measurements in stochastic simulation of groundwater flow - a numerical experiment using MATLAB}
author = {Eriksson, L O, and Oppelstrup, J}
abstractNote = {A simulator for 2D stochastic continuum simulation and inverse modelling of groundwater flow has been developed. The simulator is well suited for method evaluation and what-if simulation and written in MATLAB. Conductivity fields are generated by unconditional simulation, conditional simulation on measured conductivities and calibration on both steady-state head measurements and transient head histories. The fields can also include fracture zones and zones with different mean conductivities. Statistics of conductivity fields and particle travel times are recorded in Monte-Carlo simulations. The calibration uses the pilot point technique, an inverse technique proposed by RamaRao and LaVenue. Several Kriging procedures are implemented, among others Kriging neighborhoods. In cases where the expectation of the log-conductivity in the truth field is known the nonbias conditions can be omitted, which will make the variance in the conditionally simulated conductivity fields smaller. A simulation experiment, resembling the initial stages of a site investigation and devised in collaboration with SKB, is performed and interpreted. The results obtained in the present study show less uncertainty than in our preceding study. This is mainly due to the modification of the Kriging procedure but also to the use of more data. Still the large uncertainty in cases of sparse data is apparent. The variogram represents essential characteristics of the conductivity field. Thus, even unconditional simulations take account of important information. Significant improvements in variance by further conditioning will be obtained only as the number of data becomes much larger. 16 refs, 26 figs.}
place = {Sweden}
year = {1994}
month = {Dec}
}
title = {Calibration with respect to hydraulic head measurements in stochastic simulation of groundwater flow - a numerical experiment using MATLAB}
author = {Eriksson, L O, and Oppelstrup, J}
abstractNote = {A simulator for 2D stochastic continuum simulation and inverse modelling of groundwater flow has been developed. The simulator is well suited for method evaluation and what-if simulation and written in MATLAB. Conductivity fields are generated by unconditional simulation, conditional simulation on measured conductivities and calibration on both steady-state head measurements and transient head histories. The fields can also include fracture zones and zones with different mean conductivities. Statistics of conductivity fields and particle travel times are recorded in Monte-Carlo simulations. The calibration uses the pilot point technique, an inverse technique proposed by RamaRao and LaVenue. Several Kriging procedures are implemented, among others Kriging neighborhoods. In cases where the expectation of the log-conductivity in the truth field is known the nonbias conditions can be omitted, which will make the variance in the conditionally simulated conductivity fields smaller. A simulation experiment, resembling the initial stages of a site investigation and devised in collaboration with SKB, is performed and interpreted. The results obtained in the present study show less uncertainty than in our preceding study. This is mainly due to the modification of the Kriging procedure but also to the use of more data. Still the large uncertainty in cases of sparse data is apparent. The variogram represents essential characteristics of the conductivity field. Thus, even unconditional simulations take account of important information. Significant improvements in variance by further conditioning will be obtained only as the number of data becomes much larger. 16 refs, 26 figs.}
place = {Sweden}
year = {1994}
month = {Dec}
}