Modelling Soil Water Retention Curves Using Van Genuchten's Model for Several Agricultural Soils in Jordan

Amayreh, Jumah; Al-Abed, Nassim; Nassar, Abeer; Massad, Eva; Alrousan, Linda; Amer, Ezdehar Bany

doi:10.1080/03650340310001594844

Cited by 2 publications

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“…The van Genuchten and Campbell PTF models were selected for this study because they have been widely used and evaluated for a wide range of soil types (Khaleel et al, 1995;Rockström et al, 1998;Schaap and Leij, 2000;Cornelis et al, 2001;Wagner et al, 2001;Amayreh et al, 2003). The Vauclin PTF model was originally developed for sandy soils of Senegal (Vauclin et al, 1983a) and later successfully used for Niger sandy soils with similar properties (Klaij and Vachaud, 1992).…”

Section: Introductionmentioning

confidence: 99%

Modeling hydraulic properties of sandy soils of Niger using pedotransfer functions

et al. 2007

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Direct determination of soil hydraulic properties is often costly and laborious hence the use of indirect methods such as pedotransfer functions (PTFs). Despite progress made in PTF development in general, little evaluation of PTFs has been done for the sandy soils of Niger. We tested the ability of three PTFs, (Campbell, van Genuchten, and Vauclin) to determine soil water retention and unsaturated hydraulic conductivity (K) for sandy soils at two villages (Banizoumbou and Bagoua) in Niger. Modeled K was compared to K estimated from neutron probe readings at 1.4 m; and modeled moisture retention was compared to lab measurements derived from the hanging water column method and pressure plate apparatus for the following depth intervals: 0-30, 30-60, and N 60 cm at Banizoumbou; and 0-30, 30-120, and N120 cm at Bagoua. The Campbell PTF resulted in lower root mean square error (RMSE) (0.05-0.06 m 3 m − 3 ) for soil moisture retention for the three depth intervals at the two sites and performed better than the van Genuchten function (RMSE 0.06-0.07 m 3 m − 3 ) for Bagoua soils which had higher sand content. The van Genuchten PTF consistently overestimated dry regime moisture retention for the three depth intervals especially at Bagoua but performed well for the wet regime. The Campbell and Vauclin PTFs underestimated K (RMSE 0.61-1.01 mm d − 1 ) at both sites whereas the van Genuchten model was close to field measurements (RMSE 0.26-0.47 mm d − 1 ). These results show that the Campbell model is a cheaper alternative to direct measurement of moisture retention and the van Genuchten function can be used to estimate K for Niger's sandy soils with modest accuracy.

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Section: Introductionmentioning

confidence: 99%

Modeling hydraulic properties of sandy soils of Niger using pedotransfer functions

et al. 2007

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Prediction of soil hydraulic parameters by inverse method using genetic algorithm optimization under field conditions

Mahbod

Zand‐Parsa

2010

Archives of Agronomy and Soil Science

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In this study, soil hydraulic parameters were estimated by the inverse method in field conditions. At basins of 2 6 2 m, soil water content reached near saturation point up to about 1 m depth. Afterwards, the surfaces of the plots were covered by plastic sheets and the soil water content and pressure head were measured daily by TDR (time-domain reflectrometry) and ceramic tensiometers at different soil depths up to seven or 10 days later. The amounts of soil water content and pressure head were predicted in a profile by solving Richards' equation, applying the finite difference method. The values of soil hydraulic parameters [the parameters of soil water characteristic curve and matched saturated hydraulic conductivity (K o )] were estimated by inverse method in which minimization of errors at different depths and times after wetting was obtained using genetic algorithm (GA). For prediction of soil hydraulic parameters, the ESHPIM2 model was developed based on the linkage of Richards' equation and GA method. The results showed that using the ESHPIM2 model was favorable. Because the effects of macropores in the movement of water under the inverse method were not taken into consideration, the predicted values of K o were much lower than those measured by saturated hydraulic conductivity in field conditions.

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Modelling Soil Water Retention Curves Using Van Genuchten's Model for Several Agricultural Soils in Jordan

Cited by 2 publications

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Modeling hydraulic properties of sandy soils of Niger using pedotransfer functions

Modeling hydraulic properties of sandy soils of Niger using pedotransfer functions

Prediction of soil hydraulic parameters by inverse method using genetic algorithm optimization under field conditions

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