A large fraction of the fresh water available for human use is stored in groundwater aquifers. Si... more A large fraction of the fresh water available for human use is stored in groundwater aquifers. Since human activities such as mining, agriculture, industry and urbanisation often result in incursion of various pollutants to groundwater, routine monitoring of water quality is an indispensable component of judicious aquifer management. Unfortunately, groundwater pollution monitoring is expensive and usually cannot cover an aquifer with the spatial resolution necessary for making adequate management decisions. Interpolation of monitoring data is thus an important tool for supplementing monitoring observations. However, interpolating routine groundwater pollution data poses a special problem due to the nature of the observations. The data from a producing aquifer usually includes many zero pollution concentration values from the clean parts of the aquifer but may span a wide range of values (up to a few orders of magnitude) in the polluted areas. This manuscript presents a methodology that can cope with such datasets and use them to produce maps that present the pollution plumes but also delineates the clean areas that are fit for production. A method for assessing the quality of mapping in a way which is suitable to the data's dynamic range of values is also presented. A local variant of inverse distance weighting is employed to interpolate the data. Inclusion zones around the interpolation points ensure that only relevant observations contribute to each interpolated concentration. Using inclusion zones improves the accuracy of the mapping but results in interpolation grid points which are not assigned a value. The inherent trade-off between the interpolation accuracy and coverage is demonstrated using both circular and elliptical inclusion zones. A leave-one-out cross testing is used to assess and compare the performance of the interpolations. The methodology is demonstrated using groundwater pollution monitoring data from the coastal aquifer along the Israeli shoreline. The implications for aquifer management are discussed.
Water repellency has a significant impact on water flow patterns in the soil profile. Flow tends ... more Water repellency has a significant impact on water flow patterns in the soil profile. Flow tends to become unstable in such soils, which affects the water availability to plants and subsurface hydrology. In this paper, water flow in repellent soils was experimentally studied using the light reflection method. The transient 2D moisture profiles were monitored by CCD camera for tested soils packed in a transparent flow chamber. Water infiltration experiments and subsequent redistribution from on-surface and subsurface point sources with different flow rates were conducted for two soils of different repellency degrees as well as for wettable soil. We used spatio-statistical analysis (moments) to characterize the flow patterns. The zeroth moment is related to the total volume of water inside the moisture plume, and the first and second moments are affinitive to the center of mass and spatial variances of the moisture plume, respectively. The experimental results demonstrate that both th...
... to a self-organizing nonlinear output model for cloud patched-based rainfall estimation and .... more ... to a self-organizing nonlinear output model for cloud patched-based rainfall estimation and ... data dimensionality is far from being uniform (note that we consider 61 time steps, but ... for modeling water dynamics in complex systems, where mechanistic-model based prediction is not ...
Egu General Assembly Conference Abstracts, May 1, 2010
Geophysical investigation is a powerful tool that allows non-invasive and non-destructive mapping... more Geophysical investigation is a powerful tool that allows non-invasive and non-destructive mapping of subsurface states and properties. However, non-uniqueness associated with the inversion process halts these methods from becoming of more quantitative use. One major direction researchers are going is constraining the inverse problem by hydrological observations and models. An alternative to the commonly used direct inversion methods are global optimization schemes (such as genetic algorithms and Monte Carlo Markov Chain methods). However, the major limitation here is the desired high resolution of the tomographic image, which leads to a large number of parameters and an unreasonably high computational effort when using global optimization schemes. One way to overcome these problems is to combine the advantages of both direct and global inversion methods through hierarchical inversion. That is, starting the inversion with relatively coarse resolution of parameters, achieving good inversion using one of the two inversion schemes (global or direct), and then refining the resolution and applying a combination of global and direct inversion schemes for the whole domain or locally. In this work we explore through synthetic case studies the option of using a global optimization scheme for inversion of electrical resistivity tomography data through hierarchical refinement of the model resolution.
ABSTRACT Biofilm effects on water flow in unsaturated environments have largely been ignored in t... more ABSTRACT Biofilm effects on water flow in unsaturated environments have largely been ignored in the past. However, intensive engineered systems that involve elevated organic loads such as wastewater irrigation, effluent recharge and bioremediation processes make understanding how biofilms affect flow highly important. In the current work we present a channel-network model that incorporates water flow, substrate transport and biofilm dynamics to simulate the alteration of soil hydraulic properties, namely water retention and conductivity. The change in hydraulic properties due to biofilm growth is not trivial and depends highly on the spatial distribution of the biofilm development. Our results indicate that the substrate mass transfer coefficient across the water-biofilm interface dominates the spatio-temporal distribution of biofilm. High mass transfer coefficients lead to uncontrolled biofilm growth close to the substrate source, resulting in preferential clogging of the soil. Low mass transfer coefficients, on the other hand, lead to a more uniform biofilm distribution. The first scenario leads to a dramatic reduction of the hydraulic conductivity with almost no change in water retention, whereas the second scenario has a smaller effect on conductivity but a larger influence on retention. The current modeling approach identifies key factors that still need to be studied and opens the way for simulation and optimization of processes involving significant biological activity in unsaturated soils.
Although often composing a non-negligible fraction of soil cation exchange capacity (CEC), the im... more Although often composing a non-negligible fraction of soil cation exchange capacity (CEC), the impact of soil organic matter (OM) on the electrical properties of soil has not been thoroughly investigated. In this research the impact of soil OM on the spectral induced polarization (SIP) signature of soil was investigated. Electrical and chemical measurements for two experiments using the same soil, one with calcium as the dominant cation and the other with sodium, with different concentration of OM were performed. Our results show that despite the high CEC of OM, a decrease in polarization and an increase in relaxation time with increasing concentration of OM is observed. For the soil with calcium as the dominant cation, the decreases in polarization and the increase in relaxation time were stronger. We explain these non-trivial results by accounting for the interactions between the OM and the soil minerals. We suggest that the formation of organo-mineral complexes reduce ionic mobil...
1] In this study, the influence of a free phase nonaqueous phase liquid (NAPL), decane, on the so... more 1] In this study, the influence of a free phase nonaqueous phase liquid (NAPL), decane, on the soil's SIP signature was experimentally investigated. The complex electrical conductivity was determined using the SIP measurement system and compared between two main treatment types: clean and decane contaminated. Complementary chemical and temporal measurements were conducted. The results show a clear decrease in the imaginary part of the complex conductivity for the decane contaminated soil. Moreover, a shift of the relaxation frequency was observed for the contaminated soil. Our chemical analysis suggests that there was no change in the chemical composition of the Stern layer, and clearly, the grain size distribution did not change as well. Therefore, these results are attributed to membrane polarization. The decane addition to the unsaturated porous media changes the pore-scale liquid phase distribution, thus affecting membrane polarization. Further, the electrical signature is a time-related process associated with liquid phase arrangement time. The findings of this study can enable a better understanding of the SIP response for soils contaminated with free-phase organic compounds. Citation: Shefer, I., N. Schwartz, and A. Furman (2013), The effect of free-phase NAPL on the spectral induced polarization signature of variably saturated soil, Water Resour. Res., 49, 6229-6237,
Global water resources quan es and quali es are declining, but at the same me, a strong demand fo... more Global water resources quan es and quali es are declining, but at the same me, a strong demand for higher agricultural produc vity con nues to emerge due to popula on growth. This calls for a signifi cant increase of irriga on and fer liza on effi ciencies and requires improving our understanding of the interac ons between plants and their physical environment. The main objec ve of this study is to analyze the combined eff ect of varying drip irriga on management techniques and growing condi ons (media proper es and container volumes) on soil-plant interac ons. In a series of experiments, irriga on fl ow rates and intervals ranging from 2 d to 10 min were applied to the vegeta ve stage of a test crop (bell pepper [Capsicum annuum L. 'Selika']) cul vated under diff erent growing condi onssand and perlite in buckets, perlite in containers, and loamy sand under fi eld condi ons. Data on soil water regime, plant water uptake, and plant development were monitored in each setup. Large diff erences were observed both in terms of root and canopy development in response to the diff erent applica on rates and frequencies. The prevailing irriga on management refl ects on the soil water content dynamics, and consequently, on the plant water uptake and growth. Sap fl ow rates measurements indicated that higher irriga on frequency or lower water applica on rates increased plant water uptake rates. However, in most of the cases (except for the sand) it also led to a lower root mass and a smaller root mass/leaf area ra o. Interes ngly, in the single plant per bucket experiments, a larger leaf area seemed condi oned on a larger root mass, while the opposite was the case in those two experiments where plants were grown in rows (perlite in containers and loamy sand fi eld), where most prolifi c canopy development was supported by the smallest root mass. Integra ng fi ndings across the diff erent experiments, we introduce the concept of mean daily available water volume per plant as the product of container/bucket volume and mean daily water content in the medium to express the joint eff ect of constraints imposed by the physical volume of growing medium and their specifi c hydraulic proper es. Mean daily available water volume per plant was found to be posi vely correlated with the dry root mass to leaf area ra o.
available for completion of a survey isbasedon thephysi- cal process to be monitored. That is, al... more available for completion of a survey isbasedon thephysi- cal process to be monitored. That is, all measurements Asimpleyetpowerfulalgorithmispresentedfortheoptimalalloca- comprising a survey must bemade rapidly compared with tion ofelectrical resistivitytomography (ERT)electrodes tomaximize measurement quality. The algorithm makes use of a definition of the the rate at which the electrical conductivity changes in sensitivity of an ERT array to a series of
electrode arrays allows for the interpretation of the twodimensional distribution of electrical c... more electrode arrays allows for the interpretation of the twodimensional distribution of electrical conductivity in the The analytic element method is used to investigate the spatial subsurface. The electrical conductivity distribution can sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we then be related to the volumetric water content, concenwere able to generate maps showing the distribution of the sensitivity tration of electrolytic solutes in the pore water, and the throughout the subsurface. This allows us to define regions of the surface conductivity of the subsurface materials.
electrode arrays allows for the interpretation of the twodimensional distribution of electrical c... more electrode arrays allows for the interpretation of the twodimensional distribution of electrical conductivity in the The analytic element method is used to investigate the spatial subsurface. The electrical conductivity distribution can sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we then be related to the volumetric water content, concenwere able to generate maps showing the distribution of the sensitivity tration of electrolytic solutes in the pore water, and the throughout the subsurface. This allows us to define regions of the surface conductivity of the subsurface materials.
Journal of Irrigation and Drainage Engineering, 2007
This study addresses infiltration from furrows or narrow channels. The basic approach is to devel... more This study addresses infiltration from furrows or narrow channels. The basic approach is to develop the two-dimensional infiltration as a combination of the corresponding one-dimensional vertical and an edge effect. The idea is borrowed from previous applications for infiltration from disc and strip sources. The assumption is tested directly with numerical experiments using four representative soils and three furrow shapes ͑triangular, rectangular, and parabolic͒. The edge effect is the difference between the cumulative infiltration per unit of adjusted wetting perimeter and the corresponding one-dimensional infiltration. A general conclusion is that the edge effect is linearly related to time. In addition, it was observed that the two empirical parameters in the function used to relate the edge effect with time have narrow ranges and are related to soil hydraulic parameters, furrow shape, the boundary and initial conditions and additional geometric factors. The approach leads to a physically based infiltration function for irrigation furrows ͑or narrow channels͒ without the need to perform a fully two-dimensional simulation. Also, a simplified expression was found for the limiting steady-state case, which is analogous to Wooding's equation for infiltration from a shallow pond.
... under the active aquifer. Historical deep drills in nearby regions indicate that such a subaq... more ... under the active aquifer. Historical deep drills in nearby regions indicate that such a subaquifer exists and its chemical characteristics may be similar to that of the Be'er Tuvia plume ( Vengosh and Ben-Zvi, 1994). The objective of ...
An artificial neural network (ANN) technology is presented as an alternative to physical-based mo... more An artificial neural network (ANN) technology is presented as an alternative to physical-based modeling of subsurface water distribution from trickle emitters. Three options are explored to prepare inputoutput functional relations from a database created using a numerical model (HYDRUS-2D). From the database the feasibility and advantages of the three alternative options are evaluated: water-content at defined coordinates, moment analysis describing the shape of the plume, and coordinates of individual water-content contours. The best option is determined in a way by the application objectives, but results suggest that prediction using moment analyses is probably the most versatile and robust and gives an adequate picture of the subsurface distribution. Of the other two options, the direct determination of the individual water contours was subjectively judged to be more successful than predicting the water content at given coordinates, at least in terms of describing the subsurface distribution. The results can be used to estimate subsurface water distribution for essentially any soil properties, initial conditions or flow rates for trickle sources.
A large fraction of the fresh water available for human use is stored in groundwater aquifers. Si... more A large fraction of the fresh water available for human use is stored in groundwater aquifers. Since human activities such as mining, agriculture, industry and urbanisation often result in incursion of various pollutants to groundwater, routine monitoring of water quality is an indispensable component of judicious aquifer management. Unfortunately, groundwater pollution monitoring is expensive and usually cannot cover an aquifer with the spatial resolution necessary for making adequate management decisions. Interpolation of monitoring data is thus an important tool for supplementing monitoring observations. However, interpolating routine groundwater pollution data poses a special problem due to the nature of the observations. The data from a producing aquifer usually includes many zero pollution concentration values from the clean parts of the aquifer but may span a wide range of values (up to a few orders of magnitude) in the polluted areas. This manuscript presents a methodology that can cope with such datasets and use them to produce maps that present the pollution plumes but also delineates the clean areas that are fit for production. A method for assessing the quality of mapping in a way which is suitable to the data's dynamic range of values is also presented. A local variant of inverse distance weighting is employed to interpolate the data. Inclusion zones around the interpolation points ensure that only relevant observations contribute to each interpolated concentration. Using inclusion zones improves the accuracy of the mapping but results in interpolation grid points which are not assigned a value. The inherent trade-off between the interpolation accuracy and coverage is demonstrated using both circular and elliptical inclusion zones. A leave-one-out cross testing is used to assess and compare the performance of the interpolations. The methodology is demonstrated using groundwater pollution monitoring data from the coastal aquifer along the Israeli shoreline. The implications for aquifer management are discussed.
Water repellency has a significant impact on water flow patterns in the soil profile. Flow tends ... more Water repellency has a significant impact on water flow patterns in the soil profile. Flow tends to become unstable in such soils, which affects the water availability to plants and subsurface hydrology. In this paper, water flow in repellent soils was experimentally studied using the light reflection method. The transient 2D moisture profiles were monitored by CCD camera for tested soils packed in a transparent flow chamber. Water infiltration experiments and subsequent redistribution from on-surface and subsurface point sources with different flow rates were conducted for two soils of different repellency degrees as well as for wettable soil. We used spatio-statistical analysis (moments) to characterize the flow patterns. The zeroth moment is related to the total volume of water inside the moisture plume, and the first and second moments are affinitive to the center of mass and spatial variances of the moisture plume, respectively. The experimental results demonstrate that both th...
... to a self-organizing nonlinear output model for cloud patched-based rainfall estimation and .... more ... to a self-organizing nonlinear output model for cloud patched-based rainfall estimation and ... data dimensionality is far from being uniform (note that we consider 61 time steps, but ... for modeling water dynamics in complex systems, where mechanistic-model based prediction is not ...
Egu General Assembly Conference Abstracts, May 1, 2010
Geophysical investigation is a powerful tool that allows non-invasive and non-destructive mapping... more Geophysical investigation is a powerful tool that allows non-invasive and non-destructive mapping of subsurface states and properties. However, non-uniqueness associated with the inversion process halts these methods from becoming of more quantitative use. One major direction researchers are going is constraining the inverse problem by hydrological observations and models. An alternative to the commonly used direct inversion methods are global optimization schemes (such as genetic algorithms and Monte Carlo Markov Chain methods). However, the major limitation here is the desired high resolution of the tomographic image, which leads to a large number of parameters and an unreasonably high computational effort when using global optimization schemes. One way to overcome these problems is to combine the advantages of both direct and global inversion methods through hierarchical inversion. That is, starting the inversion with relatively coarse resolution of parameters, achieving good inversion using one of the two inversion schemes (global or direct), and then refining the resolution and applying a combination of global and direct inversion schemes for the whole domain or locally. In this work we explore through synthetic case studies the option of using a global optimization scheme for inversion of electrical resistivity tomography data through hierarchical refinement of the model resolution.
ABSTRACT Biofilm effects on water flow in unsaturated environments have largely been ignored in t... more ABSTRACT Biofilm effects on water flow in unsaturated environments have largely been ignored in the past. However, intensive engineered systems that involve elevated organic loads such as wastewater irrigation, effluent recharge and bioremediation processes make understanding how biofilms affect flow highly important. In the current work we present a channel-network model that incorporates water flow, substrate transport and biofilm dynamics to simulate the alteration of soil hydraulic properties, namely water retention and conductivity. The change in hydraulic properties due to biofilm growth is not trivial and depends highly on the spatial distribution of the biofilm development. Our results indicate that the substrate mass transfer coefficient across the water-biofilm interface dominates the spatio-temporal distribution of biofilm. High mass transfer coefficients lead to uncontrolled biofilm growth close to the substrate source, resulting in preferential clogging of the soil. Low mass transfer coefficients, on the other hand, lead to a more uniform biofilm distribution. The first scenario leads to a dramatic reduction of the hydraulic conductivity with almost no change in water retention, whereas the second scenario has a smaller effect on conductivity but a larger influence on retention. The current modeling approach identifies key factors that still need to be studied and opens the way for simulation and optimization of processes involving significant biological activity in unsaturated soils.
Although often composing a non-negligible fraction of soil cation exchange capacity (CEC), the im... more Although often composing a non-negligible fraction of soil cation exchange capacity (CEC), the impact of soil organic matter (OM) on the electrical properties of soil has not been thoroughly investigated. In this research the impact of soil OM on the spectral induced polarization (SIP) signature of soil was investigated. Electrical and chemical measurements for two experiments using the same soil, one with calcium as the dominant cation and the other with sodium, with different concentration of OM were performed. Our results show that despite the high CEC of OM, a decrease in polarization and an increase in relaxation time with increasing concentration of OM is observed. For the soil with calcium as the dominant cation, the decreases in polarization and the increase in relaxation time were stronger. We explain these non-trivial results by accounting for the interactions between the OM and the soil minerals. We suggest that the formation of organo-mineral complexes reduce ionic mobil...
1] In this study, the influence of a free phase nonaqueous phase liquid (NAPL), decane, on the so... more 1] In this study, the influence of a free phase nonaqueous phase liquid (NAPL), decane, on the soil's SIP signature was experimentally investigated. The complex electrical conductivity was determined using the SIP measurement system and compared between two main treatment types: clean and decane contaminated. Complementary chemical and temporal measurements were conducted. The results show a clear decrease in the imaginary part of the complex conductivity for the decane contaminated soil. Moreover, a shift of the relaxation frequency was observed for the contaminated soil. Our chemical analysis suggests that there was no change in the chemical composition of the Stern layer, and clearly, the grain size distribution did not change as well. Therefore, these results are attributed to membrane polarization. The decane addition to the unsaturated porous media changes the pore-scale liquid phase distribution, thus affecting membrane polarization. Further, the electrical signature is a time-related process associated with liquid phase arrangement time. The findings of this study can enable a better understanding of the SIP response for soils contaminated with free-phase organic compounds. Citation: Shefer, I., N. Schwartz, and A. Furman (2013), The effect of free-phase NAPL on the spectral induced polarization signature of variably saturated soil, Water Resour. Res., 49, 6229-6237,
Global water resources quan es and quali es are declining, but at the same me, a strong demand fo... more Global water resources quan es and quali es are declining, but at the same me, a strong demand for higher agricultural produc vity con nues to emerge due to popula on growth. This calls for a signifi cant increase of irriga on and fer liza on effi ciencies and requires improving our understanding of the interac ons between plants and their physical environment. The main objec ve of this study is to analyze the combined eff ect of varying drip irriga on management techniques and growing condi ons (media proper es and container volumes) on soil-plant interac ons. In a series of experiments, irriga on fl ow rates and intervals ranging from 2 d to 10 min were applied to the vegeta ve stage of a test crop (bell pepper [Capsicum annuum L. 'Selika']) cul vated under diff erent growing condi onssand and perlite in buckets, perlite in containers, and loamy sand under fi eld condi ons. Data on soil water regime, plant water uptake, and plant development were monitored in each setup. Large diff erences were observed both in terms of root and canopy development in response to the diff erent applica on rates and frequencies. The prevailing irriga on management refl ects on the soil water content dynamics, and consequently, on the plant water uptake and growth. Sap fl ow rates measurements indicated that higher irriga on frequency or lower water applica on rates increased plant water uptake rates. However, in most of the cases (except for the sand) it also led to a lower root mass and a smaller root mass/leaf area ra o. Interes ngly, in the single plant per bucket experiments, a larger leaf area seemed condi oned on a larger root mass, while the opposite was the case in those two experiments where plants were grown in rows (perlite in containers and loamy sand fi eld), where most prolifi c canopy development was supported by the smallest root mass. Integra ng fi ndings across the diff erent experiments, we introduce the concept of mean daily available water volume per plant as the product of container/bucket volume and mean daily water content in the medium to express the joint eff ect of constraints imposed by the physical volume of growing medium and their specifi c hydraulic proper es. Mean daily available water volume per plant was found to be posi vely correlated with the dry root mass to leaf area ra o.
available for completion of a survey isbasedon thephysi- cal process to be monitored. That is, al... more available for completion of a survey isbasedon thephysi- cal process to be monitored. That is, all measurements Asimpleyetpowerfulalgorithmispresentedfortheoptimalalloca- comprising a survey must bemade rapidly compared with tion ofelectrical resistivitytomography (ERT)electrodes tomaximize measurement quality. The algorithm makes use of a definition of the the rate at which the electrical conductivity changes in sensitivity of an ERT array to a series of
electrode arrays allows for the interpretation of the twodimensional distribution of electrical c... more electrode arrays allows for the interpretation of the twodimensional distribution of electrical conductivity in the The analytic element method is used to investigate the spatial subsurface. The electrical conductivity distribution can sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we then be related to the volumetric water content, concenwere able to generate maps showing the distribution of the sensitivity tration of electrolytic solutes in the pore water, and the throughout the subsurface. This allows us to define regions of the surface conductivity of the subsurface materials.
electrode arrays allows for the interpretation of the twodimensional distribution of electrical c... more electrode arrays allows for the interpretation of the twodimensional distribution of electrical conductivity in the The analytic element method is used to investigate the spatial subsurface. The electrical conductivity distribution can sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we then be related to the volumetric water content, concenwere able to generate maps showing the distribution of the sensitivity tration of electrolytic solutes in the pore water, and the throughout the subsurface. This allows us to define regions of the surface conductivity of the subsurface materials.
Journal of Irrigation and Drainage Engineering, 2007
This study addresses infiltration from furrows or narrow channels. The basic approach is to devel... more This study addresses infiltration from furrows or narrow channels. The basic approach is to develop the two-dimensional infiltration as a combination of the corresponding one-dimensional vertical and an edge effect. The idea is borrowed from previous applications for infiltration from disc and strip sources. The assumption is tested directly with numerical experiments using four representative soils and three furrow shapes ͑triangular, rectangular, and parabolic͒. The edge effect is the difference between the cumulative infiltration per unit of adjusted wetting perimeter and the corresponding one-dimensional infiltration. A general conclusion is that the edge effect is linearly related to time. In addition, it was observed that the two empirical parameters in the function used to relate the edge effect with time have narrow ranges and are related to soil hydraulic parameters, furrow shape, the boundary and initial conditions and additional geometric factors. The approach leads to a physically based infiltration function for irrigation furrows ͑or narrow channels͒ without the need to perform a fully two-dimensional simulation. Also, a simplified expression was found for the limiting steady-state case, which is analogous to Wooding's equation for infiltration from a shallow pond.
... under the active aquifer. Historical deep drills in nearby regions indicate that such a subaq... more ... under the active aquifer. Historical deep drills in nearby regions indicate that such a subaquifer exists and its chemical characteristics may be similar to that of the Be'er Tuvia plume ( Vengosh and Ben-Zvi, 1994). The objective of ...
An artificial neural network (ANN) technology is presented as an alternative to physical-based mo... more An artificial neural network (ANN) technology is presented as an alternative to physical-based modeling of subsurface water distribution from trickle emitters. Three options are explored to prepare inputoutput functional relations from a database created using a numerical model (HYDRUS-2D). From the database the feasibility and advantages of the three alternative options are evaluated: water-content at defined coordinates, moment analysis describing the shape of the plume, and coordinates of individual water-content contours. The best option is determined in a way by the application objectives, but results suggest that prediction using moment analyses is probably the most versatile and robust and gives an adequate picture of the subsurface distribution. Of the other two options, the direct determination of the individual water contours was subjectively judged to be more successful than predicting the water content at given coordinates, at least in terms of describing the subsurface distribution. The results can be used to estimate subsurface water distribution for essentially any soil properties, initial conditions or flow rates for trickle sources.
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Papers by Alex Furman