IAHR, founded in 1935, is a worldwide independent memberbased organisation of engineers and water specialists working in fields related to the hydroenvironmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and ecohydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.





Concentration statistics for nonergodic 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 largescale advection and porescale 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 logconductivity variance, ¾2Y. Under nonergodic transport, the uncertainty in the prediction of the barycenter of the plume maybe described by a multinormal 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 twoparticle 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 







