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 Author:
 Dagan, G., et al. ; Fiori, A.; Zarlenga, A.; Jankovic, I.; Show all 4 Authors
 Source:
 Advances in water resources 2017 v.110 pp. 349359
 ISSN:
 03091708
 Subject:
 advection; aquifers; autocorrelation; equations; field experimentation; least squares; mathematical models; prediction; solutes; steady flow; uncertainty; variance
 Abstract:
 ... Natural gradient steady flow of mean velocity U takes place in heterogeneous aquifers of random logconductivity Y=lnK, characterized by the normal univariate PDF f(Y) and autocorrelation ρY, of variance σY2 and horizontal integral scale I. Solute transport is quantified by the Breakthrough Curve (BTC) M at planes at distance x from the injection plane. The study builds on the extensive 3D numerica ...
 DOI:
 10.1016/j.advwatres.2017.10.025

http://dx.doi.org/10.1016/j.advwatres.2017.10.025
 Author:
 Dagan, G., et al. ; Jankovic, I.; Maghrebi, M.; Fiori, A.; Show all 4 Authors
 Source:
 Advances in water resources 2017 v.100 pp. 199211
 ISSN:
 03091708
 Subject:
 aquifers; autocorrelation; geometry; permeability; prediction; solutes; statistical models; steady flow; variance
 Abstract:
 ... Natural gradient steady flow of mean velocity U takes place in heterogeneous aquifers of random logconductivity Y=lnK, characterized by the univariate PDF f(Y) and autocorrelation ρY. Solute transport is analyzed through the Breakthrough Curve (BTC) at planes at distance x from the injection plane. The study examines the impact of permeability structures sharing same f(Y) and ρY, but differing in ...
 DOI:
 10.1016/j.advwatres.2016.10.024

http://dx.doi.org/10.1016/j.advwatres.2016.10.024
 Author:
 Dagan, G., et al. ; Cvetkovic, V.; Fiori, A.; Show all 3 Authors
 Source:
 Journal of hydrology 2016 v.543 pp. 101108
 ISSN:
 00221694
 Subject:
 aquifers; groundwater flow; hydraulic conductivity; hydrodynamics; mass transfer; statistical analysis; travel
 Abstract:
 ... The driving mechanism of tracer transport in aquifers is groundwater flow which is controlled by the heterogeneity of hydraulic properties. We show how hydrodynamics and mass transfer are coupled in a general analytical manner to derive a physicallybased (or processbased) residence time distribution for a given integral scale of the hydraulic conductivity; the result can be applied for a broad c ...
 DOI:
 10.1016/j.jhydrol.2016.04.072

https://dx.doi.org/10.1016/j.jhydrol.2016.04.072
 Author:
 Dagan, G., et al. ; Rabinovich, A.; Miloh, T.; Show all 3 Authors
 Source:
 Advances in water resources 2013 v.62 pp. 317326
 ISSN:
 03091708
 Subject:
 aquifers; hydraulic conductivity; transient flow; variance
 Abstract:
 ... We consider transient flow in 3D and 2D (regional) confined aquifers with spatially variable random hydraulic conductivity K(x) (replaced by the transmissivity T(x) for regional flow). The latter is considered a function of lognormal univariate distribution, characterized by KG (the geometric mean) and σY2, the variance of Y=lnK. The aquifer is modeled as a layer/plane composed of densely distribu ...
 DOI:
 10.1016/j.advwatres.2013.09.002

http://dx.doi.org/10.1016/j.advwatres.2013.09.002
 Author:
 Dagan, G., et al. ; Fiori, A.; Jankovic, I.; Show all 3 Authors
 Source:
 Advances in water resources 2013 v.51 pp. 6785
 ISSN:
 03091708
 Subject:
 aquifers; engineering; hydraulic conductivity; models; physics
 Abstract:
 ... We consider heterogeneous media whose properties vary in space and particularly aquifers whose hydraulic conductivity K may change by orders of magnitude in the same formation. Upscaling of conductivity in models of aquifer flow is needed in order to reduce the numerical burden, especially when modeling flow in heterogeneous aquifers of 3D random structure. Also, in many applications the interest ...
 DOI:
 10.1016/j.advwatres.2011.12.017

http://dx.doi.org/10.1016/j.advwatres.2011.12.017
 Author:
 Dagan, G., et al. ; Fiori, A.; Jankovic, I.; Show all 3 Authors
 Source:
 Advances in water resources 2011 v.34 no.12 pp. 15631573
 ISSN:
 03091708
 Subject:
 aquifers; autocorrelation; hydraulic conductivity; models; solutes; variance
 Abstract:
 ... Fluid flow and solute transport take place in a porous formation. The spatial variability of the hydraulic conductivity K has a large impact on the velocity field and advective spreading of solute. The logconductivity Y=lnK is modeled as a stationary random space function, of normal distribution of mean 〈Y〉=lnKG and variance σY ², and of isotropic autocorrelation of finite integral scale I. The st ...
 DOI:
 10.1016/j.advwatres.2011.08.010

http://dx.doi.org/10.1016/j.advwatres.2011.08.010
 Author:
 Dagan, G., et al. ; Lessoff, S.C.; Show all 2 Author
 Source:
 Water resources research 2007 v.43 no.5 pp. W05431 (12 p
 ISSN:
 00431397
 Subject:
 aquifers; steady flow; wells; hydrologic models; statistical analysis
 Abstract:
 ... Numerical solution of regionalscale aquifer flow requires discretizing the transmissivity T. Typically, the numerical element scale R and the transmissivity integral scale I are both of the order of hundreds of meters. Then the upscaled block transmissivity is random, and its statistical moments depend on those of T, on flow conditions, and on R/I. Modeling Y = ln T as a twodimensional normally ...
 DOI:
 10.1029/2006WR005235

http://dx.doi.org/10.1029/2006WR005235
 Author:
 Dagan, G., et al. ; Paster, A.; Guttman, J.; Show all 3 Authors
 Source:
 Journal of hydrology 2006 v.323 no.14 pp. 154167
 ISSN:
 00221694
 Subject:
 freshwater; mathematical models; water salinization; groundwater flow; aquifers; saline water; saltwater intrusion; groundwater; hydrologic models; Israel
 Abstract:
 ... The salinization processes of the YarkonTaninim aquifer (Israel) were investigated for many years, and so far little was known about the saline water body prevailing in the NorthWestern margin of the aquifer. The salinity of the water in this water body is close to that of seawater. Recently, in drilled wells in the Northern part of the aquifer, it was found that the freshwater and the saltwater ...
 DOI:
 10.1016/j.jhydrol.2005.08.018

http://dx.doi.org/10.1016/j.jhydrol.2005.08.018
 Author:
 Dagan, G., et al. ; Jankovic, I.; Fiori, A.; Suribhatla, R.; Show all 4 Authors
 Source:
 Ground water 2006 v.44 no.1 pp. 6271
 ISSN:
 0017467X
 Subject:
 mathematical models; groundwater flow; aquifers; hydrologic models; Nevada
 Abstract:
 ... Determination of hydraulic head, H, as a function of spatial coordinates and time, in ground water flow is the basis for aquifer management and for prediction of contaminant transport. Several computer codes are available for this purpose. Spatial distribution of the transmissivity, T(x,y), is a required input to these codes. In most aquifers, T varies in an erratic manner, and it can be character ...
 DOI:
 10.1111/j.17456584.2005.00083.x
 PubMed:
 16405467

http://dx.doi.org/10.1111/j.17456584.2005.00083.x
 Author:
 Dagan, G., et al. ; Indelman, P.; Moltyaner, G.; Show all 3 Authors
 Source:
 Ground water 1999 v.37 no.2 pp. 223227
 ISSN:
 0017467X
 Subject:
 aquifers; saturated hydraulic conductivity; spatial variation; particle size distribution; sandy soils; spatial distribution; statistical analysis; Ontario
 Abstract:
 ... Concentrations of a radiotracer were measured continuously in observation wells in a field test conducted in the sandy aquifer at the Chalk River site. These measurements were used recently (Dagan et al. 1997) to assess the values of the parameters characterizing the spatial distribution of logconductivity (mean, variance, and horizontal and vertical integral scales). Soil samples were taken indep ...
 DOI:
 10.1111/j.17456584.1999.tb00977.x

http://dx.doi.org/10.1111/j.17456584.1999.tb00977.x
 Author:
 Dagan, G., et al. ; Mualem, Y.; Show all 2 Author
 Source:
 Soil Science Society of America journal 1978 v.42 no.3 pp. 392395
 ISSN:
 03615995
 Subject:
 empirical research; equations; porous media; soil types; statistical models; unsaturated hydraulic conductivity
 Abstract:
 ... Conceptual theory of the hydraulic conductivity of unsaturated porous media is presented. This analysis permits us to derive systematically the models of R. C. Childs and N. Collis George (1950), M. R. J. Wyllie and G. H. F. Gardner (1958) and Y. Mualem (1976) as well as other existing and new versions, from some common statistical principles. The resulting formulas of unsaturated hydraulic conduc ...
 DOI:
 10.2136/sssaj1978.03615995004200030003x

https://dx.doi.org/10.2136/sssaj1978.03615995004200030003x
 Author:
 Dagan, G., et al. ; Bresler, E.; Hanks, R. J.; Show all 3 Authors
 Source:
 Soil Science Society of America journal 1982 v.46 no.4 pp. 841847
 ISSN:
 03615995
 Subject:
 crop yield; field experimentation; irrigation rates; soil heterogeneity; sprinkler irrigation; statistical inference; variance
 Abstract:
 ... The linesource sprinkler irrigation system produces a water application pattern which is uniform along the length of the plot and variable across the plot. This ensures a high degree of uniformity of deterministic water application along strips parallel to the sprinkler line and minimizes effect of irrigation variability upon yield in such strips. Statistical techniques are applied to analyze yie ...
 DOI:
 10.2136/sssaj1982.03615995004600040035x

https://dx.doi.org/10.2136/sssaj1982.03615995004600040035x
 Author:
 Dagan, G., et al. ; Bresler, Eshel; Wagenet, R. J.; Laufer, A.; Show all 4 Authors
 Source:
 Soil Science Society of America journal 1984 v.48 no.1 pp. 1625
 ISSN:
 03615995
 Subject:
 covariance; electrical conductivity; hydraulic conductivity; linear models; salinity; sand; soil salinity; soil texture; texture
 Abstract:
 ... A statistical analysis that identifies the dominant factors responsible for the spatial variability of the saturated conductivity (Kₛ) in a selected field is presented. The variables are considered random functions of the space coordinates. Two types of stationarity are investigated: constant mean and stationary variogram (stationarity of order 2) and trend of the means (nonstationarity of the mat ...
 DOI:
 10.2136/sssaj1984.03615995004800010004x

https://dx.doi.org/10.2136/sssaj1984.03615995004800010004x
 Author:
 Dagan, G., et al. ; Bresler, Eshel; Dasberg, S.; Russo, D.; Show all 4 Authors
 Source:
 Soil Science Society of America journal 1981 v.45 no.3 pp. 600605
 ISSN:
 03615995
 Subject:
 Arachis hypogaea; autocorrelation; dry matter accumulation; hay; irrigation; peanuts; pods; soil water; soil water content; yield components
 Abstract:
 ... In a heterogeneous field in which the soil water properties vary, the yield of a crop may also differ from point to point. Using actual field variability data of irrigated peanut (Arachis hypogaea L.) yield, of soil water properties, and stochastic approaches, effects of spatial variability of soil water on the crop yield distribution and on the spatial correlation structures are evaluated. Values ...
 DOI:
 10.2136/sssaj1981.03615995004500030032x

https://dx.doi.org/10.2136/sssaj1981.03615995004500030032x