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You are here : eLibrary : IAHR World Congress Proceedings : 32nd Congress - Venice (2007) : THEME B: Data Acquisition and Processing For Scientific Knowledge and Public Awareness. : Concentration statistics for non-ergodic transport with finite peclet values in porous heterogeneous...
Concentration statistics for non-ergodic transport with finite peclet values in porous heterogeneous ¶ formations
Author : MATTEO NICOLINI , VIRGILIO FIOROTTO , ELPIDIO CARONI
Natural porous formations are inherently heterogeneous, and solute plumes transportedby large-scale advection and pore-scale dispersion are characterized by very irregularshapes. Most of environmental regulations define water quality standards and acceptability in terms of concentration thresholds, thus the prediction in natural aquifers shouldbe performed with reference to the concentration probability of excess relative to therelevant threshold value. Moreover, ergodicity for a solute plume is satis¯ed if its initialsize is much larger than the characteristic size of the heterogeneity, which is rarely truein practice. In this work, an analytical procedure for the calculation of concentrationpdf is presented, assuming small values of the log-conductivity variance, ¾2Y. Under nonergodic transport, the uncertainty in the prediction of the barycenter of the plume maybe described by a multi-normal random variate, as con¯rmed by a series of Monte Carloanalyses: this allows an estimate of the overall concentration pdf, which may be obtainedby the analytical convolution between the two distributions, in which the covariances ofthe trajectory of the center of mass of a given plume are calculated starting from the elements of the two-particle displacement covariance matrix.
File Size : 214,884 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 32nd Congress - Venice (2007)
Article : THEME B: Data Acquisition and Processing For Scientific Knowledge and Public Awareness.
Date Published : 01/07/2007
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