נגישות
menu      
Advanced Search
Syntax
Search...
Volcani treasures
About
Terms of use
Manage
Community:
אסיף מאגר המחקר החקלאי
Powered by ClearMash Solutions Ltd -
Stochastic analysis of solute mass flux in gravity-dominated flow through bimodal heterogeneous unsaturated formations
Year:
2005
Source of publication :
Vadose Zone Journal
Authors :
Russo, David
;
.
Volume :
4
Co-Authors:
Russo, D., Dep. of Environmental Physics, Irrigation Institute of Soils, Water and Environmental Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Facilitators :
From page:
939
To page:
953
(
Total pages:
15
)
Abstract:
First-order analysis, based on a stochastic continuum presentation of flow and a general Lagrangian description of transport, was used to investigate the effects of several characteristics of a bimodal, spatially heterogeneous, variably saturated formation, on solute breakthrough curves, under steady-state, gravity-dominated unsaturated flow conditions. The bimodal formation was viewed as a mixture of two populations (background soil and embedded soil) of differing hydraulic properties and differing spatial structures. Results of the present analysis, restricted to relatively small inclusions' volume fraction, suggest that as in saturated flow, for a formation of given statistics and mean water saturation, both the spreading of the mean solute breakthrough curve and the uncertainty in its prediction may be appreciable, especially in bimodal formations in which: (i) the contrast between the mean properties of the two subdomains is relatively large, (ii) the inclusions' volume fraction is relatively large, and (iii) the characteristic length scales of the inclusions are relatively large as compared with those of the heterogeneity of the background soil. Results of this study, unique to unsaturated flow conditions, stem from the inherent concave nature of the log-conductivity variance-mean pressure head relationships in bimodal, variably saturated formations. Consequently, under unsaturated flow conditions, both the spreading of the mean solute discharge and the uncertainty in its prediction are concave functions of mean saturation. Starting with saturated formation, they initially decrease with decreasing mean saturation, reach their minima, and then increase as mean saturation further decreases, exceeding their counterparts in saturated flow conditions. Implications of the results with respect to the problem of groundwater contamination where risk assessment is required, are briefly discussed. © Soil Science Society of America.
Note:
Related Files :
groundwater
Groundwater contamination
Risk assessment
Soils
Sub-domains
Water saturations
Show More
Related Content
More details
DOI :
10.2136/vzj2004.0183
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
26656
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:24
You may also be interested in
Scientific Publication
Stochastic analysis of solute mass flux in gravity-dominated flow through bimodal heterogeneous unsaturated formations
4
Russo, D., Dep. of Environmental Physics, Irrigation Institute of Soils, Water and Environmental Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Stochastic analysis of solute mass flux in gravity-dominated flow through bimodal heterogeneous unsaturated formations
First-order analysis, based on a stochastic continuum presentation of flow and a general Lagrangian description of transport, was used to investigate the effects of several characteristics of a bimodal, spatially heterogeneous, variably saturated formation, on solute breakthrough curves, under steady-state, gravity-dominated unsaturated flow conditions. The bimodal formation was viewed as a mixture of two populations (background soil and embedded soil) of differing hydraulic properties and differing spatial structures. Results of the present analysis, restricted to relatively small inclusions' volume fraction, suggest that as in saturated flow, for a formation of given statistics and mean water saturation, both the spreading of the mean solute breakthrough curve and the uncertainty in its prediction may be appreciable, especially in bimodal formations in which: (i) the contrast between the mean properties of the two subdomains is relatively large, (ii) the inclusions' volume fraction is relatively large, and (iii) the characteristic length scales of the inclusions are relatively large as compared with those of the heterogeneity of the background soil. Results of this study, unique to unsaturated flow conditions, stem from the inherent concave nature of the log-conductivity variance-mean pressure head relationships in bimodal, variably saturated formations. Consequently, under unsaturated flow conditions, both the spreading of the mean solute discharge and the uncertainty in its prediction are concave functions of mean saturation. Starting with saturated formation, they initially decrease with decreasing mean saturation, reach their minima, and then increase as mean saturation further decreases, exceeding their counterparts in saturated flow conditions. Implications of the results with respect to the problem of groundwater contamination where risk assessment is required, are briefly discussed. © Soil Science Society of America.
Scientific Publication
You may also be interested in