The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into ... more The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into the wastes accommodated in near surface waste disposal facility (NSDF). It is important to assess the hydraulic performance of MLCS before deploying it in the field. For this purpose, an instrumented three-layered soil column representing MLCS was subjected to 1.5 m constant ponding head for 400 days. The variation of volumetric water content and soil water potential was monitored as a function of depth and time. The objective of the study is to understand the long-term hydraulic performance and rate of saturation of different layers of MLCS. Under constant water ponding, the time to saturation for 0.3 m in surface layer, 0.6 m in drainage layer and 1.0 m in hydraulic barrier layer was observed as 24, 223 and 262 days, respectively. The numerical analysis of the MLCS predicted comparable time duration of 25, 234 and 272 days, respectively. It was noted that the numerical simulation perfo...
The relationship of shoot parameters, which play a major role in transpiration, with the cracking... more The relationship of shoot parameters, which play a major role in transpiration, with the cracking of soil has rarely been investigated. Such relation helps to analyse water use efficiency accurately. This study investigated the effect of vegetation (cowpea) age on crack formation and explored any correlation between age and cracking. The age of vegetation was expressed in the form of shoot parameters (shoot length (SL) and leaf area index (LAI)). Crack formation was expressed in the form of crack intensity factor (CIF). Ten experimental test pots were used to observe crack formation on vegetated and bare soil in a greenhouse. Image analysis in the experimental pots revealed that under drying–wetting cycles, the CIF of vegetated soil increased compared with that of bare soil. There was an evident increase in CIF with SL growth, up to a threshold length (400 mm), where lateral branch growth starts forming. There was no observable increase in CIF, with further SL growth (with negligibl...
Sand-Bentonite mixtures are used in landfill liner application in appropriate proportions. Howeve... more Sand-Bentonite mixtures are used in landfill liner application in appropriate proportions. However, effort has been made to replace the sand by some waste materials like fly ash without compromising the required properties for liner construction. In recent years, many studies were carried out to determine the suitability of different fly ashes for using with bentonite based on different geotechnical parameters. On the other hand, limited studies were found in determining the unsaturated characteristics i.e. Water Retention Characteristics Curve (WRCC) of fly ash-bentonite mixes. The determination of WRCC in case of bentonite is very complexed compared to other types of clay soil due to its high shrinkage and swelling characteristics upon drying and wetting. In this study, a combined shrinkage and suction measurement was carried out in fly ash-bentonite mixes to accurately represent the WRCC under drying condition only. The shrinkage measurement was carried out using balloon method and suction measurement was carried out with the help of WP4 dew point potentiameter device. Both the shrinkage and suction results were finally used to obtain the WRCC for the different mixes. Further, the study on the variability of WRCCs for the different mixes indicates that WRCC can be represented by a generalized plot with 20% variation.
Accurate measurement of soil surface water content is vital for analyzing evaporation, partition ... more Accurate measurement of soil surface water content is vital for analyzing evaporation, partition of solar radiation, infiltration, and runoff. Color analysis of soil has already been found to be a nonintrusive, economical, and feasible approach for the measurement of surface water content. However, color contrast within the soil domain was rarely considered in color analysis approaches demonstrated by previous researchers. This color contrast occurs because of the spatial heterogeneity of light intensity in the soil domain. This study aims to demonstrate and validate a new color analysis technique for overcoming the shortcomings of previous approaches. Six series of tests were conducted to analyze the color of red soil at various surface water contents. In addition, six measured dry densities on the compaction curve were selected for validation of the proposed color analysis technique. Soil has been compacted by hand to the desired state of compaction in a small mold. Images of soil samples were captured using a commercially available camera model (NIKON COOLPIX L29, Nikon, Tokyo, Japan). The brightness variation of soil samples was quantified using the change in mean gray value of the images. A white paper was placed below the mold to consider color contrast within the soil samples. Mean gray values of all test samples were obtained using a public domain image processing program called ImageJ. Color contrast within the soil samples was equalized with respect to reference locations considered on the white paper. Mean gray value was found to decrease with the increase in surface water content. Decrement in mean gray value was found to be more significant (i.e., 14–27 %) in saturation and desaturation zones of soil water characteristic curves (SWCCs) as compared to that in the residual zone (i.e., 3–9 %) with a 3–4 % increase in surface water content. A correlation between mean gray value and surface water content was established for the red soil.
A multilayered cover (MLC) system is provided over a non-operational landfill for isolating the w... more A multilayered cover (MLC) system is provided over a non-operational landfill for isolating the waste from the atmosphere. The integrity of the MLC is dependent on the stability of the surface layer. The surface layer in the MLC is a typical case of soil–atmosphere interaction due to its exposure to variations in temperature and rainfall with time. Surface erosion is identified as one of the factors that lead to the failure of the MLC. There are no guidelines available in the literature for assessing the suitability of material and its compaction state for constructing the surface layer based on erosion resistance. Even after following the strength and hydraulic conductivity recommendations of US Environmental Protection Agency, there are cases of cover failures which are mostly attributed to rainfall runoff-induced erosion of surface layers. Therefore, the present study demonstrates the usefulness of the soil erosion index determined by well-established pinhole test for qualifying ...
The concept of sustainability has gained momentum in geotechnical and geoenvironmental projects t... more The concept of sustainability has gained momentum in geotechnical and geoenvironmental projects that has direct or indirect influence on ecological balance and environmental management. Utilizing sustainable materials, preferably biomaterials, and improving its durability by minimizing degradation with time needs systematic interdisciplinary research. This paper discuss about bio-geotechnical interface where biomaterials are used as amendment for robust and self-sustaining green infrastructure. The need for bio-geotechnological advancement for catering to the research questions related to the use of appropriate biomaterials as soil amendment, green infrastructure, and bioengineering, vegetation for soil and water conservation, local flora for mitigating climate change is highlighted. The need to integrate the realms of geotechnical and biotechnical discipline for this purpose has been brought forth. The paper further summarizes the future direction of research for planning and executing bio-geotechnical interventions for sustainable geotechnics.
Rainfall forecasting is a high-priority research problem due to the complex interplay of multiple... more Rainfall forecasting is a high-priority research problem due to the complex interplay of multiple factors. Despite extensive studies, a systematic quantitative review of recent developments in rainfall forecasting is lacking in the literature. This study conducted a systematic quantitative review of statistical, numerical weather prediction (NWP) and machine learning (ML) techniques for rainfall forecasting. The review adopted the preferred reporting items for systematic reviews and meta-analyses (PRISMA) technique for screening keywords and abstracts, leading to 110 qualified papers from multiple databases. The impact of rainfall threshold, meteorological parameters, topography, algorithm techniques, geographic location, the horizontal resolution of the model, and lead time on rainfall forecast was examined. The review shows the importance of precipitable water vapor (PWV) along with other meteorological parameters for accurate nowcasting in coastal and mountainous regions. An incr...
AbstractLand-use change has been identified as one of the major factors responsible for change in... more AbstractLand-use change has been identified as one of the major factors responsible for change in runoff and therefore flood risk in urban areas. The present study quantifies the flood risk imposed...
Rainfall-induced progressive soil erosion of compacted surface layer (SL) impedes the functioning... more Rainfall-induced progressive soil erosion of compacted surface layer (SL) impedes the functioning of cover system (CS) of landfills with high expected design life (≈ 100 years). The existing soil erosion models are not tested extensively for compacted soil with cracks and vegetation. This study evaluated the efficacy of three popular soil erosion models for estimating the soil loss of compacted SL of CS, which is useful for annual maintenance. The interactive effect of rainfall, vegetation and desiccation cracks on erosion of compacted surface layer was investigated under the influence of both natural and simulated rainfall events for one year. Among all, the Morgan, Morgan and Finney (MMF) model was found to be effective in predicting soil erosion of compacted SL. However, the MMF model overestimated soil erosion when the vegetation cover exceeded 60%. The soil loss estimated from Revised Universal Soil Loss Equation (RUSLE) and Water Erosion Prediction Project (WEPP) models was poor for high rainfall intensity (100 mm/h). The RUSLE and WEPP model overestimated the soil erosion for low vegetation cover (≤ 3%) and underestimated for vegetation area > 3%. The mechanism of root reinforcement, strength due to root water uptake-induced soil suction and its effect on soil loss mitigation could not be adequately captured by the existing models for compacted SL. Further studies are needed to improve the existing erosion models for incorporating the effects of desiccation and vegetation on soil loss from the compacted SL.
Soil hydraulic conductivity is a mandatory input for determining water and solute transport throu... more Soil hydraulic conductivity is a mandatory input for determining water and solute transport through soils. There are several well-established infiltrometers and permeameters for measuring in situ hydraulic conductivity. Infiltrometers measure hydraulic conductivity based on water entry into an unsaturated soil at the soil-atmosphere boundary, whereas permeameters measure the flow of water from one point to another within the soil mass. This difference in measurement philosophy, along with the methods of analysis involved in the measurement, may result in varying estimates of in situ hydraulic conductivity. This study performs an evaluation among three infiltrometers (double ring infiltrometer [DRI] and two disc infiltrometers) and two permeameters (Guelph permeameter [GP] and laboratory permeameter) for measuring hydraulic conductivity. The primary objective of this study is to appraise the variability in the measurement of in situ hydraulic conductivity for identical field conditions using different infiltrometers and permeameters. The study indicated that all the permeameters and infiltrometers exhibited reasonably good repeatability in measurements. Unlike infiltrometers, the hydraulic conductivity determined from permeameters was found to exhibit similar values for two different seasons. Infiltrometers were found to be highly sensitive to alteration in the surface pore structure due to the soil-atmosphere interaction. The statistical evaluation indicated a negative bias of disc infiltrometers when compared with DRI, whereas the comparison of disc infiltrometers has shown a bias close to zero. The results of the GP closely compared with laboratory permeameter. Both the disc infiltrometers exhibited a negative bias and weak correlation with GP measurements. In the absence of parity between infiltrometer and permeameter, the former may be a better choice for including the effect of soil surface alteration on hydrological modeling, whereas the latter can be handy for modeling water redistribution within the soil mass.
Determination of erosion characteristics is of great significance to assess the stability of geot... more Determination of erosion characteristics is of great significance to assess the stability of geotechnical infrastructures that are subjected to seepage. Hole erosion tests (HETs) are the popular and simple laboratory measurements that have been used to determine erosion characteristics. These tests are indicative of the quantity of soil loss in term of internal erosion that can occur during seepage. It is noted that there are not many studies that focus on the development of theoretical model describing the erosion process (i.e. sediment detachment and transport) in HETs. The aim of this study is to propose a theoretical model based on Bernoulli’s principle to interpret the erosion measurements from HETs and employ the results for estimating erosion characteristics of soils. An analytical equation was deduced from a physically based model incorporating Bernoulli’s principle and erosion constitutive law for internal erosion within a soil pipe driven by pressure gradient. The analytical equation could be applied to determine the temporal development of eroded soil loss, radial erosion propagation, erosion rate, hydraulic shear stress, and pressure drop. The utility of proposed analytical solution was validated using a series of HETs performed in this study. Based on the novel analytical solution, erosion characteristics could be derived from the known realistic propagation of radial erosion.
Infiltration measurements are mandatory input for hydrological modelling. Disc infiltrometer is u... more Infiltration measurements are mandatory input for hydrological modelling. Disc infiltrometer is used for determining infiltration in the field by allowing three-dimensional flow of water under the negative head at the surface. There are steady-state and transient mathematical equations for obtaining hydraulic characteristics based on disc infiltrometer measurements. Different assumptions and formulations adopted by these equations may induce analysis-dependent variability in hydraulic parameter determination from the disc infiltrometer measurements. In this study, a critical evaluation of nine mathematical equations used for determining near-surface saturated hydraulic conductivity based on mini-disc infiltrometer (MDI) measurements in the field for two different seasons is carried out. The saturated hydraulic conductivity determined by Guelph permeameter was used as the reference for evaluating the appropriateness of equations considered in this study. Considering different statistical procedures, Wooding–Gardner, Weir’s Refinement, van Genuchten Zhang, Ankeny, and Haverkamp equations identified by Bland–Altman plot are recommended as the most reliable mathematical equations that can be used for analysing MDI measurements. The appropriateness of the mathematical equation for MDI analysis with respect to soil type needs to be investigated further.
Soil hydraulic conductivity is a mandatory input for determining water and solute transport throu... more Soil hydraulic conductivity is a mandatory input for determining water and solute transport through soils. There are several well-established infiltrometers and permeameters for measuring in situ hydraulic conductivity. Infiltrometers measure hydraulic conductivity based on water entry into an unsaturated soil at the soil-atmosphere boundary, whereas permeameters measure the flow of water from one point to another within the soil mass. This difference in measurement philosophy, along with the methods of analysis involved in the measurement, may result in varying estimates of in situ hydraulic conductivity. This study performs an evaluation among three infiltrometers (double ring infiltrometer [DRI] and two disc infiltrometers) and two permeameters (Guelph permeameter [GP] and laboratory permeameter) for measuring hydraulic conductivity. The primary objective of this study is to appraise the variability in the measurement of in situ hydraulic conductivity for identical field conditio...
The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into ... more The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into the wastes accommodated in near surface waste disposal facility (NSDF). It is important to assess the hydraulic performance of MLCS before deploying it in the field. For this purpose, an instrumented three-layered soil column representing MLCS was subjected to 1.5 m constant ponding head for 400 days. The variation of volumetric water content and soil water potential was monitored as a function of depth and time. The objective of the study is to understand the long-term hydraulic performance and rate of saturation of different layers of MLCS. Under constant water ponding, the time to saturation for 0.3 m in surface layer, 0.6 m in drainage layer and 1.0 m in hydraulic barrier layer was observed as 24, 223 and 262 days, respectively. The numerical analysis of the MLCS predicted comparable time duration of 25, 234 and 272 days, respectively. It was noted that the numerical simulation perfo...
The relationship of shoot parameters, which play a major role in transpiration, with the cracking... more The relationship of shoot parameters, which play a major role in transpiration, with the cracking of soil has rarely been investigated. Such relation helps to analyse water use efficiency accurately. This study investigated the effect of vegetation (cowpea) age on crack formation and explored any correlation between age and cracking. The age of vegetation was expressed in the form of shoot parameters (shoot length (SL) and leaf area index (LAI)). Crack formation was expressed in the form of crack intensity factor (CIF). Ten experimental test pots were used to observe crack formation on vegetated and bare soil in a greenhouse. Image analysis in the experimental pots revealed that under drying–wetting cycles, the CIF of vegetated soil increased compared with that of bare soil. There was an evident increase in CIF with SL growth, up to a threshold length (400 mm), where lateral branch growth starts forming. There was no observable increase in CIF, with further SL growth (with negligibl...
Sand-Bentonite mixtures are used in landfill liner application in appropriate proportions. Howeve... more Sand-Bentonite mixtures are used in landfill liner application in appropriate proportions. However, effort has been made to replace the sand by some waste materials like fly ash without compromising the required properties for liner construction. In recent years, many studies were carried out to determine the suitability of different fly ashes for using with bentonite based on different geotechnical parameters. On the other hand, limited studies were found in determining the unsaturated characteristics i.e. Water Retention Characteristics Curve (WRCC) of fly ash-bentonite mixes. The determination of WRCC in case of bentonite is very complexed compared to other types of clay soil due to its high shrinkage and swelling characteristics upon drying and wetting. In this study, a combined shrinkage and suction measurement was carried out in fly ash-bentonite mixes to accurately represent the WRCC under drying condition only. The shrinkage measurement was carried out using balloon method and suction measurement was carried out with the help of WP4 dew point potentiameter device. Both the shrinkage and suction results were finally used to obtain the WRCC for the different mixes. Further, the study on the variability of WRCCs for the different mixes indicates that WRCC can be represented by a generalized plot with 20% variation.
Accurate measurement of soil surface water content is vital for analyzing evaporation, partition ... more Accurate measurement of soil surface water content is vital for analyzing evaporation, partition of solar radiation, infiltration, and runoff. Color analysis of soil has already been found to be a nonintrusive, economical, and feasible approach for the measurement of surface water content. However, color contrast within the soil domain was rarely considered in color analysis approaches demonstrated by previous researchers. This color contrast occurs because of the spatial heterogeneity of light intensity in the soil domain. This study aims to demonstrate and validate a new color analysis technique for overcoming the shortcomings of previous approaches. Six series of tests were conducted to analyze the color of red soil at various surface water contents. In addition, six measured dry densities on the compaction curve were selected for validation of the proposed color analysis technique. Soil has been compacted by hand to the desired state of compaction in a small mold. Images of soil samples were captured using a commercially available camera model (NIKON COOLPIX L29, Nikon, Tokyo, Japan). The brightness variation of soil samples was quantified using the change in mean gray value of the images. A white paper was placed below the mold to consider color contrast within the soil samples. Mean gray values of all test samples were obtained using a public domain image processing program called ImageJ. Color contrast within the soil samples was equalized with respect to reference locations considered on the white paper. Mean gray value was found to decrease with the increase in surface water content. Decrement in mean gray value was found to be more significant (i.e., 14–27 %) in saturation and desaturation zones of soil water characteristic curves (SWCCs) as compared to that in the residual zone (i.e., 3–9 %) with a 3–4 % increase in surface water content. A correlation between mean gray value and surface water content was established for the red soil.
A multilayered cover (MLC) system is provided over a non-operational landfill for isolating the w... more A multilayered cover (MLC) system is provided over a non-operational landfill for isolating the waste from the atmosphere. The integrity of the MLC is dependent on the stability of the surface layer. The surface layer in the MLC is a typical case of soil–atmosphere interaction due to its exposure to variations in temperature and rainfall with time. Surface erosion is identified as one of the factors that lead to the failure of the MLC. There are no guidelines available in the literature for assessing the suitability of material and its compaction state for constructing the surface layer based on erosion resistance. Even after following the strength and hydraulic conductivity recommendations of US Environmental Protection Agency, there are cases of cover failures which are mostly attributed to rainfall runoff-induced erosion of surface layers. Therefore, the present study demonstrates the usefulness of the soil erosion index determined by well-established pinhole test for qualifying ...
The concept of sustainability has gained momentum in geotechnical and geoenvironmental projects t... more The concept of sustainability has gained momentum in geotechnical and geoenvironmental projects that has direct or indirect influence on ecological balance and environmental management. Utilizing sustainable materials, preferably biomaterials, and improving its durability by minimizing degradation with time needs systematic interdisciplinary research. This paper discuss about bio-geotechnical interface where biomaterials are used as amendment for robust and self-sustaining green infrastructure. The need for bio-geotechnological advancement for catering to the research questions related to the use of appropriate biomaterials as soil amendment, green infrastructure, and bioengineering, vegetation for soil and water conservation, local flora for mitigating climate change is highlighted. The need to integrate the realms of geotechnical and biotechnical discipline for this purpose has been brought forth. The paper further summarizes the future direction of research for planning and executing bio-geotechnical interventions for sustainable geotechnics.
Rainfall forecasting is a high-priority research problem due to the complex interplay of multiple... more Rainfall forecasting is a high-priority research problem due to the complex interplay of multiple factors. Despite extensive studies, a systematic quantitative review of recent developments in rainfall forecasting is lacking in the literature. This study conducted a systematic quantitative review of statistical, numerical weather prediction (NWP) and machine learning (ML) techniques for rainfall forecasting. The review adopted the preferred reporting items for systematic reviews and meta-analyses (PRISMA) technique for screening keywords and abstracts, leading to 110 qualified papers from multiple databases. The impact of rainfall threshold, meteorological parameters, topography, algorithm techniques, geographic location, the horizontal resolution of the model, and lead time on rainfall forecast was examined. The review shows the importance of precipitable water vapor (PWV) along with other meteorological parameters for accurate nowcasting in coastal and mountainous regions. An incr...
AbstractLand-use change has been identified as one of the major factors responsible for change in... more AbstractLand-use change has been identified as one of the major factors responsible for change in runoff and therefore flood risk in urban areas. The present study quantifies the flood risk imposed...
Rainfall-induced progressive soil erosion of compacted surface layer (SL) impedes the functioning... more Rainfall-induced progressive soil erosion of compacted surface layer (SL) impedes the functioning of cover system (CS) of landfills with high expected design life (≈ 100 years). The existing soil erosion models are not tested extensively for compacted soil with cracks and vegetation. This study evaluated the efficacy of three popular soil erosion models for estimating the soil loss of compacted SL of CS, which is useful for annual maintenance. The interactive effect of rainfall, vegetation and desiccation cracks on erosion of compacted surface layer was investigated under the influence of both natural and simulated rainfall events for one year. Among all, the Morgan, Morgan and Finney (MMF) model was found to be effective in predicting soil erosion of compacted SL. However, the MMF model overestimated soil erosion when the vegetation cover exceeded 60%. The soil loss estimated from Revised Universal Soil Loss Equation (RUSLE) and Water Erosion Prediction Project (WEPP) models was poor for high rainfall intensity (100 mm/h). The RUSLE and WEPP model overestimated the soil erosion for low vegetation cover (≤ 3%) and underestimated for vegetation area > 3%. The mechanism of root reinforcement, strength due to root water uptake-induced soil suction and its effect on soil loss mitigation could not be adequately captured by the existing models for compacted SL. Further studies are needed to improve the existing erosion models for incorporating the effects of desiccation and vegetation on soil loss from the compacted SL.
Soil hydraulic conductivity is a mandatory input for determining water and solute transport throu... more Soil hydraulic conductivity is a mandatory input for determining water and solute transport through soils. There are several well-established infiltrometers and permeameters for measuring in situ hydraulic conductivity. Infiltrometers measure hydraulic conductivity based on water entry into an unsaturated soil at the soil-atmosphere boundary, whereas permeameters measure the flow of water from one point to another within the soil mass. This difference in measurement philosophy, along with the methods of analysis involved in the measurement, may result in varying estimates of in situ hydraulic conductivity. This study performs an evaluation among three infiltrometers (double ring infiltrometer [DRI] and two disc infiltrometers) and two permeameters (Guelph permeameter [GP] and laboratory permeameter) for measuring hydraulic conductivity. The primary objective of this study is to appraise the variability in the measurement of in situ hydraulic conductivity for identical field conditions using different infiltrometers and permeameters. The study indicated that all the permeameters and infiltrometers exhibited reasonably good repeatability in measurements. Unlike infiltrometers, the hydraulic conductivity determined from permeameters was found to exhibit similar values for two different seasons. Infiltrometers were found to be highly sensitive to alteration in the surface pore structure due to the soil-atmosphere interaction. The statistical evaluation indicated a negative bias of disc infiltrometers when compared with DRI, whereas the comparison of disc infiltrometers has shown a bias close to zero. The results of the GP closely compared with laboratory permeameter. Both the disc infiltrometers exhibited a negative bias and weak correlation with GP measurements. In the absence of parity between infiltrometer and permeameter, the former may be a better choice for including the effect of soil surface alteration on hydrological modeling, whereas the latter can be handy for modeling water redistribution within the soil mass.
Determination of erosion characteristics is of great significance to assess the stability of geot... more Determination of erosion characteristics is of great significance to assess the stability of geotechnical infrastructures that are subjected to seepage. Hole erosion tests (HETs) are the popular and simple laboratory measurements that have been used to determine erosion characteristics. These tests are indicative of the quantity of soil loss in term of internal erosion that can occur during seepage. It is noted that there are not many studies that focus on the development of theoretical model describing the erosion process (i.e. sediment detachment and transport) in HETs. The aim of this study is to propose a theoretical model based on Bernoulli’s principle to interpret the erosion measurements from HETs and employ the results for estimating erosion characteristics of soils. An analytical equation was deduced from a physically based model incorporating Bernoulli’s principle and erosion constitutive law for internal erosion within a soil pipe driven by pressure gradient. The analytical equation could be applied to determine the temporal development of eroded soil loss, radial erosion propagation, erosion rate, hydraulic shear stress, and pressure drop. The utility of proposed analytical solution was validated using a series of HETs performed in this study. Based on the novel analytical solution, erosion characteristics could be derived from the known realistic propagation of radial erosion.
Infiltration measurements are mandatory input for hydrological modelling. Disc infiltrometer is u... more Infiltration measurements are mandatory input for hydrological modelling. Disc infiltrometer is used for determining infiltration in the field by allowing three-dimensional flow of water under the negative head at the surface. There are steady-state and transient mathematical equations for obtaining hydraulic characteristics based on disc infiltrometer measurements. Different assumptions and formulations adopted by these equations may induce analysis-dependent variability in hydraulic parameter determination from the disc infiltrometer measurements. In this study, a critical evaluation of nine mathematical equations used for determining near-surface saturated hydraulic conductivity based on mini-disc infiltrometer (MDI) measurements in the field for two different seasons is carried out. The saturated hydraulic conductivity determined by Guelph permeameter was used as the reference for evaluating the appropriateness of equations considered in this study. Considering different statistical procedures, Wooding–Gardner, Weir’s Refinement, van Genuchten Zhang, Ankeny, and Haverkamp equations identified by Bland–Altman plot are recommended as the most reliable mathematical equations that can be used for analysing MDI measurements. The appropriateness of the mathematical equation for MDI analysis with respect to soil type needs to be investigated further.
Soil hydraulic conductivity is a mandatory input for determining water and solute transport throu... more Soil hydraulic conductivity is a mandatory input for determining water and solute transport through soils. There are several well-established infiltrometers and permeameters for measuring in situ hydraulic conductivity. Infiltrometers measure hydraulic conductivity based on water entry into an unsaturated soil at the soil-atmosphere boundary, whereas permeameters measure the flow of water from one point to another within the soil mass. This difference in measurement philosophy, along with the methods of analysis involved in the measurement, may result in varying estimates of in situ hydraulic conductivity. This study performs an evaluation among three infiltrometers (double ring infiltrometer [DRI] and two disc infiltrometers) and two permeameters (Guelph permeameter [GP] and laboratory permeameter) for measuring hydraulic conductivity. The primary objective of this study is to appraise the variability in the measurement of in situ hydraulic conductivity for identical field conditio...
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