Pedotransfer functions for predicting the hydraulic properties of Indian soils

Soil Research ◽  
2008 ◽  
Vol 46 (5) ◽  
pp. 476 ◽  
Author(s):  
Partha Pratim Adhikary ◽  
Debashis Chakraborty ◽  
Naveen Kalra ◽  
C. B. Sachdev ◽  
A. K. Patra ◽  
...  
Keyword(s):  
Soil Water ◽  
Characteristic Curve ◽  
Clay Content ◽  
Infiltration Rate ◽  
Pedotransfer Functions ◽  
Regression Equations ◽  
Hydraulic Characteristics ◽  
Indian Soils ◽  
Wide Range ◽  
Function Relationship

Most of the data pertaining to Indian soils are limited to the major soil separates, sand, silt, and clay. We examined the possibilities of using these parameters to describe the hydraulic characteristics of the soils of India. The final or steady-state infiltration rate, which is mainly profile-controlled, showed a power function relationship with the maximum and the average clay content in the soil profile. The saturated hydraulic conductivity also showed a similar relationship with the silt + clay content. The soil water content at a given suction could be satisfactorily predicted using the percentage of major soil separates, sand, silt, and clay. The coefficients in the soil water function ψ(θ) were linearly related to the sand content. Non-linear regression equations were developed to predict these coefficients using the percentages of sand and clay in soils. The equations proved to be quite satisfactory for a wide range of textures and provided reasonably accurate estimates of the soil water characteristic curve from a minimum of readily available data.

Measurement of Soil Suction and Soil-Water Characteristics of Bentonite-Sand Mixtures

2010 ◽  
Author(s):  
Pan Hu ◽  
Qing Yang ◽  
Maotian Luan
Keyword(s):  
Soil Water ◽  
Vapor Phase ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Phase Method ◽  
Soil Suction ◽  
Compacted Bentonite ◽  
Water Characteristics ◽  
Wide Range ◽  
High Level

The soil-water characteristic curve (SWCC) is a widely used experimental means for assessing fundamental properties of unsaturated soils for a wide range of soil suction values. The study of SWCC is helpful because some properties of unsaturated soils can be predicted from it. Nowadays, much attention has been paid to the behaviours of highly compacted bentonite-sand mixtures used in engineering barriers for high level radioactive nuclear waste disposal. It is very important to study the various performances of bentonite-sand mixtures in order to insure the safety of high-level radioactive waste (HLW) repository. After an introduction to vapor phase method and osmotic technique, a laboratory study has been carried out on compacted bentonite-sand mixtures. The SWCC of bentonite-sand mixtures has been obtained and analyzed. The results show that the vapor phase method and osmotic technique is suitable to the unsaturated soils with high and low suction.

scholarly journals Performance Evaluation of Four-Parameter Models of the Soil-Water Characteristic Curve

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Siti Jahara Matlan ◽  
Muhammad Mukhlisin ◽  
Mohd Raihan Taha
Keyword(s):  
Soil Water ◽  
Characteristic Curve ◽  
Data Sets ◽  
Modified Model ◽  
Soil Water Characteristic Curve ◽  
Geoenvironmental Engineering ◽  
Wide Range ◽  
Soil Water Characteristic Curves ◽  
Model Equations ◽  
Exponential Variable

Soil-water characteristic curves (SWCCs) are important in terms of groundwater recharge, agriculture, and soil chemistry. These relationships are also of considerable value in geotechnical and geoenvironmental engineering. Their measurement, however, is difficult, expensive, and time-consuming. Many empirical models have been developed to describe the SWCC. Statistical assessment of soil-water characteristic curve models found that exponential-based model equations were the most difficult to fit and generally provided the poorest fit to the soil-water characteristic data. In this paper, an exponential-based model is devised to describe the SWCC. The modified equation is similar to those previously reported by Gardner (1956) but includes exponential variable. Verification was performed with 24 independent data sets for a wide range of soil textures. Prediction results were compared with the most widely used models to assess the model’s performance. It was proven that the exponential-based equation of the modified model provided greater flexibility and a better fit to data on various types of soil.

scholarly journals New approach to improve soil-water characteristic curve to reduce variation in estimation of unsaturated permeability function

2016 ◽  
Vol 53 (4) ◽  
pp. 717-725 ◽  
Author(s):  
Arezoo Rahimi ◽  
Harianto Rahardjo
Keyword(s):  
Soil Water ◽  
Distribution Curve ◽  
Characteristic Curve ◽  
New Approach ◽  
Soil Water Characteristic Curve ◽  
Permeability Function ◽  
Wide Range ◽  
Unsaturated Permeability ◽  
Complete Measurement ◽  
Data Points

The unsaturated permeability function is often estimated from the soil-water characteristic curve (SWCC) of a soil. A complete SWCC measurement can improve the estimation of the unsaturated permeability function. In most laboratories, the SWCC can be measured up to a suction of 100 kPa using a Tempe cell. However, complete measurement of the SWCC is an expensive and time-consuming task. Therefore, this paper presents a new approach to estimate SWCC data points beyond 100 kPa suction to complement the SWCC measured up to a suction of 100 kPa. The new SWCC is then used to estimate the unsaturated permeability function. The proposed approach uses knowledge of the grain-size distribution curve and measured SWCC data at 100 kPa suction to estimate the SWCC data points beyond 100 kPa suction. To verify the proposed procedure, SWCC tests were conducted over a wide range of suctions for coarse kaolin and a triaxial permeameter system was used to directly measure unsaturated permeability of the coarse kaolin. The proposed procedure is found to reduce the variation between unsaturated permeability functions estimated by various estimation models.

scholarly journals Formation of runoff at the hillslope scale during intense precipitation

2006 ◽  
Vol 3 (4) ◽  
pp. 2523-2558 ◽  
Author(s):  
S. Scherrer ◽  
F. Naef ◽  
A. O. Faeh ◽  
I. Cordery
Keyword(s):  
Soil Water ◽  
Overland Flow ◽  
Subsurface Flow ◽  
Clay Content ◽  
Infiltration Rate ◽  
Soil Water Storage ◽  
Antecedent Soil Moisture ◽  
Near Surface ◽  
Soil Clay Content ◽  
A Site

Abstract. On 60 m2 hillslope plots at 18 mainly grassland locations in Switzerland rain was applied at rates of 50–100 mm/h for between 3 and 6 h. The generated flows were measured, overland flow near surface and subsurface flow in 0.5–1.3 m below surface. At some locations less than 2% of the rain flowed down the slope either on or below the surface, whereas at some others more than 90% of the rain ran off. At the majority of sites most runoff was overland flow, though at a few sites subsurface flow, usually via macropores was dominant. Data collected during each of 48 high intensity sprinkling experiments were used to distinguish which processes were dominant in each experiment. Which dominant and subsidiary processes occurred depended on interactions between infiltration rate, change in soil water storage and drainage of the soil water. These attributes were often not directly linked to parameters usually considered important like vegetation, slope, soil clay content and antecedent soil moisture. In many cases, process determination was fairly straightforward, indicating the possibility to reliably predict runoff processes at a site. However, at some sites, effects occurred that were not easily recognizable and led to surprising results.

A quick fix for modeling infiltration in water-repellent soils

2021 ◽  
Author(s):  
Ryan Stewart ◽  
Majdi R. Abou Najm ◽  
Simone Di Prima ◽  
Laurent Lassabatere
Keyword(s):  
Soil Water ◽  
Wide Spectrum ◽  
Correction Term ◽  
Water Repellency ◽  
Infiltration Rate ◽  
Water Repellent ◽  
Soil Water Repellency ◽  
Simple Method ◽  
Wide Range ◽  
Infiltration Models

<p>Water repellency occurs in soils under a wide spectrum of conditions. Soil water repellency can originate from the deposition of resinous materials and exudates from vegetation, vaporization and condensation of organic compounds during fires, or the presence of anthropogenic-derived chemicals like petroleum products, wastewater or other urban contaminants. Its effects on soils range from mild to severe, and it often leads to hydrophobic conditions that can significantly impact the infiltration response with effects extending to the watershed-scale. Those effects are often time-dependent, making it a challenge to simulate infiltration behaviors of water-repellent soils using standard infiltration models. Here, we introduce a single rate-constant parameter (α<sub>WR</sub>) and propose a simple correction term (1-e<sup>-αWRt</sup>) to modify models for infiltration rate. This term starts with a value of zero at the beginning of the infiltration experiment (t = 0) and asymptotically approaches 1 as time increases, thus simulating a decreasing effect of soil water repellency through time. The correction term can be added to any infiltration model (one- two- or three-dimensional) and will account for the water repellency effect. Results from 165 infiltration experiments from different ecosystems and wide range of water repellency effects validated the effectiveness of this simple method to characterize water repellency in infiltration models. Tested with the simple two-term infiltration equation developed by Philip, we obtained consistent and substantial error reductions, particularly for more repellent soils. Furthermore, results revealed that soils that were burned during a wildfire had smaller α<sub>WR</sub> values compared to unburned controls, thus indicating that the magnitude of α<sub>WR</sub> may have a physical basis.</p>

scholarly journals Soil-Water Characteristic Curve of Residual Soil from a Flysch Rock Mass

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Josip Peranić ◽  
Željko Arbanas ◽  
Sabatino Cuomo ◽  
Matej Maček
Keyword(s):  
Rock Mass ◽  
Soil Water ◽  
Characteristic Curve ◽  
Detailed Examination ◽  
Residual Soil ◽  
Residual Soils ◽  
Infiltration Process ◽  
Soil Water Characteristic Curve ◽  
Wide Range ◽  
Flysch Rock Mass

Depending on the nature of the material and suction range, laboratory measurements of the soil-water characteristic curve (SWCC) can be time-consuming and expensive, especially for residual soils, in which a wide range of particle sizes and soil structures typically results in SWCCs that cover a wide range of suction. Investigations of the SWCCs of residual soil from flysch rock masses are rare, and so far, no results were presented in the literature which were obtained by performing measurements on undisturbed specimens. In this paper, a detailed examination of water retention characteristics is performed for a specific type of residual soil (CL) formed by the weathering of a flysch rock mass. Measurements performed by using different techniques and devices on intact specimens were successfully combined to obtain the SWCC during both drying and wetting processes, under different stress conditions, and from saturated to air-dried conditions. Used procedures are suitable for the determination of SWCCs of soils that undergo volume changes during the drying or the wetting process, since instantaneous volumetric water content can be determined. Results presented in this paper can be used to assess the influence of desaturation of the residual soil covering flysch slopes during dry summer periods by providing key-in material properties required to analyze the transient rainfall infiltration process.

The relations between soil water retention characteristics, particle size distributions, bulk densities and calcium carbonate contents for Danish soils

2005 ◽  
Vol 36 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Niels Henrik Jensen ◽  
Thomas Balstrøm ◽  
Henrik Breuning-Madsen
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Pressure Head ◽  
Pedotransfer Functions ◽  
Regression Equations

A database containing about 800 soil profiles located in a 7-km grid covering Denmark has been used to develop a set of regression equations of soil water content at pressure heads −1, −10, −100 and −1500 kPa versus particle size distribution, organic matter, CaCO3 and bulk density. One purpose was to elaborate equations based on soil parameters available in the Danish Soil Classification's texture database of particle size distribution and organic matter. It was also tested to see if inclusion of bulk density or CaCO3 content (in CaCO3-containing samples) as predictors or grouping in surface and subsurface horizons or textural classes improved the regression equations. Compared to existing Danish equations based on much fewer observations the accuracies of the new equations were better. The equations also predicted the soil water content at the measured pressure heads more accurately than the pedotransfer functions developed in HYPRES (Hydraulic Properties of European Soils). Introducing bulk density as a predictor improved the equation for the pressure head of −1 kPa but not for the lower ones. The grouping of data sets in surface and subsurface horizons or in textural classes did not improve the equations. Based on the equations a set of van Genuchten parameters for soil types in the Danish Soil Classification was elaborated. The prediction of soil water content, especially at pressure head −1 kPa, is more accurate using these van Genuchten parameters than using the pedotransfer functions developed in relation to the HYPRES database from a broad range of European soils.

scholarly journals Effect of hysteresis of soil-water characteristic curves on infiltration under different climatic conditions

2016 ◽  
Vol 53 (2) ◽  
pp. 273-284 ◽  
Author(s):  
Rashid Bashir ◽  
Jitendra Sharma ◽  
Halina Stefaniak
Keyword(s):  
Soil Water ◽  
Unsaturated Soils ◽  
Unsaturated Flow ◽  
Expansive Soils ◽  
Characteristic Curve ◽  
Ground Surface ◽  
Temporal Distribution ◽  
Climatic Conditions ◽  
Wide Range ◽  
And Storage

This paper presents results of a numerical modelling exercise that investigates the effects of hysteresis of the soil-water characteristic curve (SWCC) on the infiltration characteristics of soils subjected to four different climatic conditions — from very dry to wet — within the Canadian province of Alberta. Multi-year climate datasets from four different natural regions and subregions of Alberta are compiled, classified, and applied as the soil–atmosphere boundary condition in one-dimensional finite element unsaturated flow models using Hydrus-1D software. Multi-year simulations are carried out with and without consideration of the SWCC hysteresis. Simulation results are analyzed in terms of water balance at the ground surface and temporal distribution and storage of water within the soil domain. It is demonstrated that hysteresis of the SWCC can significantly affect the prediction of flow, redistribution, and storage of water in the unsaturated zone. It is found that for soils that exhibit hysteretic SWCC, consideration of hysteresis in unsaturated flow modelling results in the prediction of lower infiltration and less movement of water through the soil. It is also found that the use of wetting parameters results in the prediction of increased infiltration and movement of water compared with the predictions using drying or hysteretic parameters. It is concluded that, for soils that exhibit a greater degree of SWCC hysteresis, it is important to measure both the drying and wetting branches of the SWCC accurately and that accurate simulation of hysteretic behaviour requires climate datasets at appropriate resolution. The results presented in this paper highlight the importance of considering SWCC hysteresis for a wide range of geotechnical problems, such as soil cover design, prediction of groundwater recharge, contaminant transport through unsaturated soils, soil erosion, slope stability, and swelling–shrinkage of expansive soils.

Research on Soil-Water Characteristic Curve of Unsaturated Mixed-Soil in West Sichuan

2013 ◽  
Vol 353-356 ◽  
pp. 996-1000
Author(s):  
Wei Guang Zhou ◽  
Yu Long Bao ◽  
Hong Bin Zhou
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Clay Content ◽  
Dry Density ◽  
Residual Moisture ◽  
Soil Water Characteristic Curve ◽  
Physical Form ◽  
Physical Composition

A series of tests are conducted to get the physical composition, physical form and the soil-water characteristic curve in different dry density of three typical composite unsaturated soils in west Sichuan. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is, the more hydrophilic mineral the soil has, the more gentle the soil-water characteristic curve is, and the higher its residual moisture content is. In addition, under the same water content, matrix suction decreases with less clay content and more content. For the three typical composite unsaturated soils, with relatively bigger water content, the change of soil-water characteristic curve resulting from variation of dry density is less, but with the water content getting smaller, the change becomes clearer.

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