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פותח על ידי קלירמאש פתרונות בע"מ -
On the spatial variability of parameters of the unsaturated hydraulic conductivity
Year:
1997
Source of publication :
Water Resources Research
Authors :
לאופר, אשר
;
.
רוסו, איתי
;
.
רוסו, דוד
;
.
Volume :
33
Co-Authors:
Russo, D., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
Russo, I., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
Laufer, A., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
Facilitators :
From page:
947
To page:
956
(
Total pages:
10
)
Abstract:
In situ measurements of discharge-head (steady state rate of water discharge and water head (Q, H)) pairs were used to estimate the saturated conductivity K(s) and the parameter α of the Gardner [1958] model of local unsaturated hydraulic conductivity at N = 152 observation points in a field plot (40 m long, 6 m wide, and 2 m deep) by means of the Geulph permeameter method. Twenty-two of these (Q, H) pairs yielded negative K(s) and were excluded from the subsequent analyses. Estimates of ln K(s) and ln α from N = 130 observation points were used to estimate parameters of the spatial covariance and the drift functions of the two soil properties, using the restricted maximum likelihood estimation procedure and the weighted least squares procedure, respectively. For both soil properties a deterministic drift was identified, suggesting that in the site under investigation, approximately 59% and 37% of the total variability of f = ln K(s) and a = ln α, respectively, may stem from large-scale variations. Results of the analyses of the uncorrelated residuals of ln K(s) and ln α suggest that both follow an approximately normal distribution and are moderately cross-correlated (ρ(fa) = 0.68). The fitted covariance models of both soil properties exhibited slight statistical anisutropy in the horizontal plane and a significant anisotropy in the vertical planes. Components of the range of ln K(s) were 2.5 m and 0.6 m in the horizontal and the vertical directions, respectively, while those of ln α were 1.4 m and 0.4 m, respectively. Estimates of the correlation scales of both properties in the horizontal plane were associated with relatively large uncertainty, which probably stemmed from the less than optimum selection of the number and locations of the observation points in this plane. The results of the model validation test, however, indicated that the fitted covariance and drift models were theoretically consistent with the observations of both soil properties.
Note:
Related Files :
Anisotropy
In-situ measurement
Soils
Soil testing
vadose zone
Vertical direction
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
27483
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:31
Scientific Publication
On the spatial variability of parameters of the unsaturated hydraulic conductivity
33
Russo, D., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
Russo, I., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
Laufer, A., Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan, Israel, Department of Soil Physics, Institute of Soils and Water, Agricultural Research Organization, Bet Dagan 50250, Israel
On the spatial variability of parameters of the unsaturated hydraulic conductivity
In situ measurements of discharge-head (steady state rate of water discharge and water head (Q, H)) pairs were used to estimate the saturated conductivity K(s) and the parameter α of the Gardner [1958] model of local unsaturated hydraulic conductivity at N = 152 observation points in a field plot (40 m long, 6 m wide, and 2 m deep) by means of the Geulph permeameter method. Twenty-two of these (Q, H) pairs yielded negative K(s) and were excluded from the subsequent analyses. Estimates of ln K(s) and ln α from N = 130 observation points were used to estimate parameters of the spatial covariance and the drift functions of the two soil properties, using the restricted maximum likelihood estimation procedure and the weighted least squares procedure, respectively. For both soil properties a deterministic drift was identified, suggesting that in the site under investigation, approximately 59% and 37% of the total variability of f = ln K(s) and a = ln α, respectively, may stem from large-scale variations. Results of the analyses of the uncorrelated residuals of ln K(s) and ln α suggest that both follow an approximately normal distribution and are moderately cross-correlated (ρ(fa) = 0.68). The fitted covariance models of both soil properties exhibited slight statistical anisutropy in the horizontal plane and a significant anisotropy in the vertical planes. Components of the range of ln K(s) were 2.5 m and 0.6 m in the horizontal and the vertical directions, respectively, while those of ln α were 1.4 m and 0.4 m, respectively. Estimates of the correlation scales of both properties in the horizontal plane were associated with relatively large uncertainty, which probably stemmed from the less than optimum selection of the number and locations of the observation points in this plane. The results of the model validation test, however, indicated that the fitted covariance and drift models were theoretically consistent with the observations of both soil properties.
Scientific Publication
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