Biexponential model for water retention characteristics

Omuto, Christian

doi:10.1016/j.geoderma.2008.12.001

Cited by 28 publications

(18 citation statements)

References 21 publications

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“…h a and θ s are soil hydraulic properties describing the shape of the wet-end of SWRC curves. Between h a and the point of complete dryness, the rate of moisture release or entry in the soil is fast or slow depending on the range of pore sizes in the soil matrix, assuming that other factors such as stress history are constant [1] [5]. For example, with narrow pore-size distribution such as in sandy soil the rate is fast (and hence the part of WRC curve between h a and point of complete dryness has a steep slope) and in broad pore-size distribution such as in clay soil the rate is slow (and WRC curve between h a and point of complete dryness has a gentle slope).…”

Section: Features Of Soil Water Retention Characteristicsmentioning

confidence: 99%

“…The rate of moisture release is very slow towards the end of a completely dry soil; thus, the slope is very gentle for this section of WRC. The slope of the dry section of SWRC intersects the slope of the section after h a at a point where the corresponding moisture content is known as residual moisture content (θ r ) [5] [8] [9] (Figure 1). …”

Section: Features Of Soil Water Retention Characteristicsmentioning

confidence: 99%

“…This is a five-parameter water retention model contained in a bimodal pore-size distribution. The parameters are for the first and second compartments [5].…”

Section: Biexponential Water Retention Modelmentioning

confidence: 99%

“…This study analyzed the performance of 10 SWRC models on their performance in the entire soil range, near saturation and near oven dryness. Table 2 shows that Biexponential model (Omuto, 2009) had the best performance statistics for the category with five-parameter models. The Gardner (1958) model had the best performance statistics in the four-parameter models category and the Exponential model had the best performance statistics in the three-parameter categories.…”

Section: Swrc Model Parametersmentioning

confidence: 99%

“…Some of the commonly used analytical models of SWRC in the literature are Brooks-Corey, Farrell-Larson, Fredlund-Xing, Gardner, McKee-Bumb, Kosugi, van Genuchten, Campbell, Russo, Tani, Omuto, and Dexter models [3]- [5]. Many of these models have been reported successful only for certain parts of SWRC (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Review of Soil Water Retention Characteristic (SWRC) Models between Saturation and Oven Dryness

Too¹,

Omuto²,

Biamah³

et al. 2014

OJMH

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Soil water retention characteristic is the key soil property used in many applications in the fields of irrigation, hydrology, geotechnical engineering and soil science in general. Since the advent of digital soil mapping and digital soil assessment paradigms, there has been an upsurge of development of soil inference models and the need to increase accurate application of soil mapping products. All soils can be partially saturated with water and also near oven dryness. Therefore, constitutive models for soils should ideally represent the soil behaviour over entire range. This paper reviewed commonly used SWRC models. In order to stem potential for biasness, the models were grouped into three categories depending on the number of fitting parameters, namely, fiveparameter, four-parameter and three-parameter categories. The evaluation used correlation and residual standard error statistics to choose the best overall performing model and in each category. Its results serve as a guide for selecting the models to be preferred for fitting SWRC in case there are limitations to the number of suction potential levels in the measured data.

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Section: Features Of Soil Water Retention Characteristicsmentioning

confidence: 99%

Section: Features Of Soil Water Retention Characteristicsmentioning

confidence: 99%

“…This is a five-parameter water retention model contained in a bimodal pore-size distribution. The parameters are for the first and second compartments [5].…”

Section: Biexponential Water Retention Modelmentioning

confidence: 99%

Section: Swrc Model Parametersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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