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

Matlan, Siti Jahara; Mukhlisin, Muhammad; Taha, Mohd Raihan

doi:10.1155/2014/569851

Cited by 20 publications

(13 citation statements)

References 19 publications

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“…Soil moisture based models have also been reported. A similar work has been reported in [8]. Many empirical model has been developed to describe the soil water characteristic curve.…”

Section: Introductionmentioning

confidence: 78%

An Empirical Exponential Model based on Reflectivity Measurements for Soil Nitrogen Detection

Lourembam¹,

Mukherjee²

2017

IJCA

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Right amount of nutrients in soil plays an important role in maintaining the health of the plant as well as the soil. In this regard, developing novel ways of soil macronutrient detection has become a must in the present day scenario. Studies based on diffused reflectance for detecting soil nutrients and attributes have taken great strides towards building up more effective systems. These trends have been contributing significantly to precision farming. Reflectance measurements in the near-infrared region have proved to be reliable in terms of measuring various soil attributes like pH, organic matter and soil nutrients. In the current work, a system was designed using an NIR source of 850nm to detect the amount of nitrogen present in soil. It was used to collect the reflectivity of the sample when variable amount of chemical was added which was then correlated to the output voltage. Based on the raw data collected, a mathematical model was developed through statistical analysis. The exponential based model was found to have the best fit with the characteristic data obtained from the sensor when analyzed statistically. The model performance estimated for the optimized combination were R 2 of 0.99 and RMSE of 0.5. Moreover, an algorithm based on this model was tested and validated with a success rate of 90%. Based on the thresholds obtained from experimentation, an Arduino was programmed in order to detect the presence of nitrogen in soil as low, medium and high. The system so designed can be employed as a cost-effective optical sensor for detection of soil nitrogen and can make a significant impact on precision farming.

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“…Soil moisture based models have also been reported. A similar work has been reported in [8]. Many empirical model has been developed to describe the soil water characteristic curve.…”

Section: Introductionmentioning

confidence: 78%

An Empirical Exponential Model based on Reflectivity Measurements for Soil Nitrogen Detection

Lourembam¹,

Mukherjee²

2017

IJCA

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“…Van Genuchten model assumes that the main drying curves retention and wetting can be described accurately by the expression: (Matlan et al 2014) S r = (|1 + |αS| η ) −m , S < 0 and = 1, S ≥ 0…”

Section: Methods Of Van Genuchten (1980)mentioning

confidence: 99%

“…The mathematical representation which is the characteristic curve is usually hyperbolic type. (Otálvaro, 2013), (Matlan et al 2014). In formulations obtained to estimate the characteristic of the soils are:…”

Section: State Of Artmentioning

confidence: 99%

Simulation of the soil-water characteristic curve using laboratory tests and empirical models for Cubans unsaturated soils

Tristá

Sotolongo

Cristiá

et al. 2016

Revista de la Construcción

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The task of characterizing an unsaturated soil is a very hard one, unlike the classics hypothesis like 100% of saturation are not considerable now. This work focuses on obtaining and simulating the soil-water characteristic curve for unsaturated soils from: Sagua la Grande, Formation Capdevila, Cienfuegos and Mariel, located in four provinces of Cuba. The estimation of the characteristic soil has different purposes that can be used to obtain various parameters which are important in the description of unsaturated soils. The permeability, shear strength and volumetric behavior are soil properties that are affected by the suction variation. For each soil case study, the characteristic curve is obtained using the filter paper test laboratory. The simulation is performed through Van Genuchten, Fredlund & Xing, and Gallipoli methods, that are empirical models and the curve is hyperbolic shaped. The statistical analysis helped to determine which of the models fit the properties of soils described by the experimental values.Keywords: soil-water characteristic curve, unsaturated soils, suction, degree of saturation, simulation. ResumenEn el trabajo se presenta la obtención y simulación de la curva característica, para cuatro suelos no saturados, pertenecientes a las localidades de Sagua la Grande, la Formación Capdevila, Cienfuegos y el Mariel ubicadas en cuatro provincias de Cuba. La estimación de la curva característica del suelo tiene diversos intereses pudiéndose emplear para obtener varios parámetros utilizados en la descripción de los suelos no saturados. La permeabilidad, la resistencia al cortante así como el comportamiento volumétrico son propiedades del suelo que se ven afectadas por la variación de la succión. Para cada suelo de estudio se obtienen la curva característica empleando el ensayo de laboratorio del papel de filtro, y la simulación se realizará mediante la utilización de métodos de Van Genuchten, Fredlund & Xing, y Gallipoli, que son modelos empíricos y la curva es de tipo hiperbólica, determinando mediante análisis estadísticos cual es el modelo que se ajusta a los valores experimentales.Palabras Claves: Curva de característica del suelo, suelo no saturado, succión, grado de saturación, simulación.23

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“…Several researchers have proposed various forms of mathematically defined SWCC models to characterize the soil water characteristic curve. In this context, the van Genuchten (1980) and the Fredlund and Xing (1994) models probably P. Habasimbi, T. Nishimura International Journal of Geosciences remain the most common mathematical concept among researchers and practicing engineers which have been widely adopted in both geotechnical and agricultural related fields [22]. In this research, an attempt was made to derive the parameters of the soil water characteristic curves obtained under different stress conditions using the two mentioned mathematical models.…”

Section: Prediction Of Model Parametersmentioning

confidence: 99%

Soil Water Characteristic Curve of an Unsaturated Soil under Low Matric Suction Ranges and Different Stress Conditions

Habasimbi¹,

Nishimura²

2019

IJG

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Accurate evaluation of unsaturated soil properties is critical for the design of geotechnical and geo-environmental structures such as road pavements, foundations, and earth dams. Water retention activity in soils which is used to predict the stability or seepage problems in the ground is one of the key features in unsaturated soil mechanics. Thus, many experimental works have reported on the unsaturated soil properties, and the soil-water characteristic curve (SWCC) test has contributed significantly to the interpretation of matric suction. Since traditional instruments cannot apply stress in SWCC tests, some researchers have developed suction controlled triaxial apparatus, by which SWCC tests are performed under different stress states. Determination of SWCCs under stress conditions similar to those in the field is key for interpretation of the hydro-mechanical behavior of unsaturated soils. This study conducted SWCC tests of unsaturated silt soil in low matric suction ranges under both drying and wetting conditions. The SWCCs were measured under one-dimensional and isotropic confining stresses ranging from 50 to 450 kPa. The micro porous membrane method was used instead of high air entry ceramic disk for controlling relatively low matric suction. The range of matric suction controlled was from 0 to 20 kPa. The study revealed that the measured SWCC in low matric suction ranges seems to be affected by the influence of stress conditions. Isotropic confining stress caused the void structure of the specimen to become dense and consequently, soil moisture flow movement also decreased. The water retention activity was obviously high, and the point regard to air entry value was larger. The study further suggests that the current methods adopted for estimating unsaturated soil properties require further development to take into account the effect of different stress conditions. How to cite this paper: Habasimbi, P. and Nishimura, T.

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

Cited by 20 publications

References 19 publications

An Empirical Exponential Model based on Reflectivity Measurements for Soil Nitrogen Detection

An Empirical Exponential Model based on Reflectivity Measurements for Soil Nitrogen Detection

Simulation of the soil-water characteristic curve using laboratory tests and empirical models for Cubans unsaturated soils

Soil Water Characteristic Curve of an Unsaturated Soil under Low Matric Suction Ranges and Different Stress Conditions

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