An analytical approach to predict the moistened bulb volume beneath a surface point source

Hammami, Majdi; Khemaies, Zayani

doi:10.1016/j.agwat.2015.12.020

Cited by 34 publications

(19 citation statements)

References 35 publications

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“…In what follows, the volume of the wetted bulb V b (t) [L 3 ] is assumed to be of an ellipsoidal shape which horizontal and vertical diagonals are respectively confined with soil surface and symmetry axis. According to Hammami and Zayani [3], V b (t) is given by:…”

Section: Theoretical Basismentioning

confidence: 99%

“…Subsequently, water evaporation and weeds proliferation are reduced. Thus, concomitant agricultural activities are possible [1][2][3]. 2) the reduction of the moistened soil volume.…”

Section: Introductionmentioning

confidence: 99%

“…2) the reduction of the moistened soil volume. Therefore, less deep-water percolation, less fertilizers' leaching and less water table contamination are expected [3]. Thus, wise trickle irrigation management requires the computation of the fraction of the effectively wetted soil volume P. It is worth emphasizing that the inference of P is challenging insofar as it depends on more or less hardly predictable factors such as roots' length density, distribution uniformity, initial water content, physical soil properties, etc.…”

Section: Introductionmentioning

confidence: 99%

“…These solutions are based on the following assumptions: (1) the surface evaporation is linearly dependent on the matric flux potential and (2) the hydraulic conductivity is an exponential function of the pressure head and soil depth. Hammami and Zayani [3] developed an analytical method to estimate the volume of the wetted bulb underneath a surface emitter. This method is based on the following hypothesis: (1) the wetted soil depth is inferred from the surface wetted radius according to the method of Hammami et al [21], (2) the water flow is of piston-type and (3) the wetted bulb is of semi-elliptical shape which diagonals are confined with the soil surface and the symmetry axis, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…This method is based on the following hypothesis: (1) the wetted soil depth is inferred from the surface wetted radius according to the method of Hammami et al [21], (2) the water flow is of piston-type and (3) the wetted bulb is of semi-elliptical shape which diagonals are confined with the soil surface and the symmetry axis, respectively. This paper is devoted to expanding the approach of Hammami and Zayani [3] to the computation of emitters' density and water supplies. The implementation of the proposed approach is assessed with respect to study cases.…”

Section: Introductionmentioning

confidence: 99%

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Optimizing Emitters’ Density and Water Supplies in Trickle Irrigation Systems

Moncef¹

2019

AJWSE

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The usual approaches for designing trickle irrigation systems are based upon empirical estimation of the emitters' density and the moistened soil volume. The objective of this paper is to implement a quasi-analytical approach that allows the inference of these two parameters. The emitters' density is determined so that the rooted soil volume would be moistened even at the peak period. The proposed approach enables to adjust the irrigation time in order to replenish the rooted soil volume up to a threshold for an optimal plant growth. The required inputs are: the water retention curve, the hydraulic conductivity at the wetting front, the radius of the moistened spot at the soil surface, and the rooted soil depth. The method is assessed with respect to study cases for sandy and silty soils. The used emitters' discharge were 2 l/h and 4 l/h. The present approach has the advantage of preserving the mass conservation as well as the dynamic aspect of irrigation management. For design purpose, the irrigation time is set equal to the time required to attain a quasi-state flow conditions within the rooted zone. Nevertheless, irrigation time should vary so that design errors are adjusted for irrigation scheduling needs.

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Section: Theoretical Basismentioning

confidence: 99%

“…Subsequently, water evaporation and weeds proliferation are reduced. Thus, concomitant agricultural activities are possible [1][2][3]. 2) the reduction of the moistened soil volume.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Optimizing Emitters’ Density and Water Supplies in Trickle Irrigation Systems

Moncef¹

2019

AJWSE

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Subsurface flow model for estimating 2D wetting pattern in drip irrigation

Reddy,

Singh

2024

CLEAN Soil Air Water

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Numerical model using 2D Richard’s equation in cylindrical polar coordinate system was developed to assess the soil wetting patterns in a drip irrigation system. A fully implicit finite‐difference scheme was used to solve equations with suitable initial and boundary conditions. The developed model was validated with an experimental result available in the literature, which shows a high level of concordance with low values of RMSE and R2 greater than 0.93 for all discharge rates. Furthermore, the versatility and applicability of the model were demonstrated for complex subsurface conditions considering homogeneous and heterogeneous soil profiles. Water ponding on the surface was observed in clay loam soil, contrasting with deep percolation in sandy loam soil. This underscores the significance of adjusting both discharge rate and irrigation frequency in accordance with prevailing soil conditions.

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Empirical models for calculating soil wetting patterns under surface drip irrigation systems: A comprehensive analysis

Li,

Nie,

2024

Irrigation and Drainage

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Accurate estimation of the surface wetted radius (R) and vertical wetted depth (Z) of wetting patterns in drip irrigation systems is crucial for ensuring that the designs of such systems are effective. This study compared 14 empirical models for estimating drip irrigation wetting patterns by assessing their accuracy using published measurement data and HYDRUS‐2D/3D simulations. The technique for order of preference by similarity to the ideal solution (TOPSIS) was employed to comprehensively rank the models. The results indicate that the empirical model proposed by Fan et al. (2023) (FY) exhibited the highest accuracy when the estimations of R and measured and simulated values were compared, with mean absolute error (MAE), root mean square error (RMSE), Nash–Sutcliffe modelling efficiency (NSE), and percent bias (PB) values of 2.2 cm, 3.4 cm, 0.79, and −7.1% and 5.2 cm, 7.0 cm, 0.50, and −14.1%, respectively. The empirical model proposed by Amin and Ekhmaj (2006) (AE) demonstrated the highest accuracy when the estimations of Z were compared with measured and simulated values, with MAE, RMSE, NSE and PB values of 1.7 cm, 2.0 cm, 0.95 and 4.15% and 4.4 cm, 5.9 cm, 0.82 and 4.7%, respectively. The comprehensive rankings of available models in the present study indicate that the FY model is the most universally applicable, followed by the Li et al. (2022) (LY) model, with comprehensive indices of 0.960 and 0.936, respectively. This research can aid in the selection of universally applicable, reliable and straightforward empirical models for estimating wetting patterns in drip irrigation systems.

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An analytical approach to predict the moistened bulb volume beneath a surface point source

Cited by 34 publications

References 35 publications

Optimizing Emitters’ Density and Water Supplies in Trickle Irrigation Systems

Optimizing Emitters’ Density and Water Supplies in Trickle Irrigation Systems

Subsurface flow model for estimating 2D wetting pattern in drip irrigation

Empirical models for calculating soil wetting patterns under surface drip irrigation systems: A comprehensive analysis

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