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פותח על ידי קלירמאש פתרונות בע"מ -
Stochastic analysis of macrodispersion in heterogeneous bimodal variably saturated formations: The effect of water saturation
Year:
2004
Source of publication :
Water Resources Research
Authors :
רוסו, דוד
;
.
Volume :
40
Co-Authors:
Russo, D., Dept. of Environ. Phys. and Irrigat., Inst. Soils, Water and Environ. Sci., Volcani Center, Bet Dagan, Israel, Dept. of Environ. Phys. and Irrigat., Inst. Soils, Water and Environ. Sci., Volcani Center, Bet Dagan 50250, Israel
Facilitators :
From page:
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Total pages:
1
)
Abstract:
The effect of water saturation on macrodispersion in bimodal, heterogeneous, variably saturated formations under steady state, gravity-dominated flow conditions was analyzed here. The present study was motivated by the inconsistency between the results of the first-order analysis of Russo [2002] and those of the simulations of Russo et al. [2001]. The latter results suggested that near saturation, increasing mean pressure head H (i.e., decreasing water saturation) may decrease log conductivity variance, σy2, and concurrently, may decrease macrodispersion, while the former results suggested the opposite. Results of the present first-order analysis suggest that this inconsistency stems from the fact that σy2 derived by Russo [2002] is valid only for H = 0. The σy2 derived in the present study, valid for H ≥ 0, is a concave function of H, which exhibits a minimum at H = H m, (Hm > 0), and may exceed its counterpart in saturated flow when H > Hc (Hc > Hm). The latter σy2 leads to a time-dependent macrodispersion tensor whose principal components decrease with increasing H when 0 < H < Hm′ (Hm′ < H m) and increase with increasing H when H > Hm′ and may exceed their counterparts in saturated flow when H > H c′, (Hc′ < Hc), consistent with the results of the simulations of Russo et al. [2001]. Results of the present analysis suggest that for a formation of given statistics and for relatively small inclusions volume fraction P* when the formation is relatively wet, i.e., when 0 < H < Hc′, the macrodispersion is larger in formations in which the texture of the embedded soil is finer than that of the background soil, while the converse is true when the formation becomes less saturated, i.e., when H > Hc′. When P* is relatively large, however, the reverse situation occurs.
Note:
Related Files :
computer simulation
Gravity-dominated flow
heterogeneous medium
Macrodispersion
Spatial heterogeneity
stochasticity
Tensors
water
עוד תגיות
תוכן קשור
More details
DOI :
10.1029/2004WR003045
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
21959
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:48
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Scientific Publication
Stochastic analysis of macrodispersion in heterogeneous bimodal variably saturated formations: The effect of water saturation
40
Russo, D., Dept. of Environ. Phys. and Irrigat., Inst. Soils, Water and Environ. Sci., Volcani Center, Bet Dagan, Israel, Dept. of Environ. Phys. and Irrigat., Inst. Soils, Water and Environ. Sci., Volcani Center, Bet Dagan 50250, Israel
Stochastic analysis of macrodispersion in heterogeneous bimodal variably saturated formations: The effect of water saturation
The effect of water saturation on macrodispersion in bimodal, heterogeneous, variably saturated formations under steady state, gravity-dominated flow conditions was analyzed here. The present study was motivated by the inconsistency between the results of the first-order analysis of Russo [2002] and those of the simulations of Russo et al. [2001]. The latter results suggested that near saturation, increasing mean pressure head H (i.e., decreasing water saturation) may decrease log conductivity variance, σy2, and concurrently, may decrease macrodispersion, while the former results suggested the opposite. Results of the present first-order analysis suggest that this inconsistency stems from the fact that σy2 derived by Russo [2002] is valid only for H = 0. The σy2 derived in the present study, valid for H ≥ 0, is a concave function of H, which exhibits a minimum at H = H m, (Hm > 0), and may exceed its counterpart in saturated flow when H > Hc (Hc > Hm). The latter σy2 leads to a time-dependent macrodispersion tensor whose principal components decrease with increasing H when 0 < H < Hm′ (Hm′ < H m) and increase with increasing H when H > Hm′ and may exceed their counterparts in saturated flow when H > H c′, (Hc′ < Hc), consistent with the results of the simulations of Russo et al. [2001]. Results of the present analysis suggest that for a formation of given statistics and for relatively small inclusions volume fraction P* when the formation is relatively wet, i.e., when 0 < H < Hc′, the macrodispersion is larger in formations in which the texture of the embedded soil is finer than that of the background soil, while the converse is true when the formation becomes less saturated, i.e., when H > Hc′. When P* is relatively large, however, the reverse situation occurs.
Scientific Publication
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