Ridge Basis Functions Collocation Method for Soil Water Movement Equations Under Infiltration with Two Point-source Emitters

Due to the nonlinear diffusion term, it is hard to use the collocation method to solve the unsaturated soil water movement equation directly. In this paper, a nonmesh Hermite collocation method with radial basis functions was proposed to solve the nonlinear unsaturated soil water movement equation with the Neumann boundary condition. By preprocessing the nonlinear diffusion term and using the Hermite radial basis function to deal with the Neumann boundary, the phenomenon that the collocation method cannot be used directly is avoided. The numerical results of unsaturated soil moisture movement with Neumann boundary conditions on the regular and nonregular regions show that the new method improved the accuracy significantly, which can be used to solve the low precision problem for the traditional collocation method when simulating the Neumann boundary condition problem. Moreover, the effectiveness and reliability of the algorithm are proved by the one-dimensional and two-dimensional engineering problem of soil water infiltration in arid area. It can be applied to engineering problems.

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Experimental and Numerical Analysis of Drip Tape Layout for Irrigation of Sugarcane in Latosol

The Open Biotechnology Journal ◽

10.2174/1874070701509010265 ◽

2015 ◽

Vol 9 (1) ◽

pp. 265-271 ◽

Cited By ~ 2

Author(s):

Kai Huang ◽

Desuo Cai ◽

Jinchuang Jinchuang ◽

Wei Pan

Keyword(s):

Point Source ◽

Soil Water ◽

Drip Irrigation ◽

Water Movement ◽

Discharge Rate ◽

Single Point ◽

Critical Parameters ◽

Irrigation Uniformity ◽

Emitter Discharge ◽

Soil Water Movement

A laboratory soil column experiment was first conducted to analyze water movement in latosol of sugarcane field under drip irrigation from single-point source at different emitter discharge rates. Next, a mathematical model of soil water movement under drip irrigation from single-point source was built using Hydrus-3D, which could accurately simulate the shape of the wetted soil volume and the distribution of volumetric water content in the experiment. Further, a Hydrus- 3D model of soil water movement under drip irrigation from double-point source was built and then used to analyze the effects of critical parameters on irrigation uniformity. Results showed that emitter spacing affected irrigation uniformity greatly, but emitter discharge rate did not. According to the irrigation uniformity, project cost and operational management patterns, appropriate drip tape parameters for irrigation of sugarcane in latosol were determined: emitter discharge rate 1.38 L/h, emitter spacing 30 cm, and single-emitter irrigation volume 9.0 L.

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Soil water movement under a drip irrigation double-point source

Water Science & Technology Water Supply ◽

10.2166/ws.2015.045 ◽

2015 ◽

Vol 15 (5) ◽

pp. 924-932

Author(s):

Lizhu Hou ◽

Jie Shang ◽

Jiangtao Liu ◽

Haiyuan Lu ◽

Zhiming Qi

Keyword(s):

Soil Moisture ◽

Point Source ◽

Soil Water ◽

Drip Irrigation ◽

Double Point ◽

Water Movement ◽

Time Domain Reflectometry ◽

Runoff Water ◽

Surface Drip Irrigation ◽

Soil Water Movement

Particularly in dry regions, the scarcity of high-quality fresh water has heightened the importance of urban runoff water re-use, leading as well to the improvement of water use efficiency through the surface drip irrigation method. Given the limited research on wetting front migration under a surface drip irrigation emitter, soil water movement under a double-point-source irrigation emitter was investigated. An experimental soil bin was designed and filled with silt loam soil, and time domain reflectometry and tensiometers were used to measure soil moisture contents and soil water potential, respectively. The results show that under the conditions of 6 hours of irrigation with two drippers each delivering 1.05 L hr−1 and spaced at 45 cm, the soil moisture content of the 0–30 cm layer increased rapidly and reached 0.29 cm3 cm−3, and was greater than that in the 30–60 cm layer as irrigation proceeded. After 6 hours the irrigation was stopped, such that in the redistribution phase, soil moisture of the top layer gradually decreased, while that of the sublayer gradually increased. The results indicate that 6 hours of irrigation under given emitter flow conditions produced adequate soil moisture down to 30 cm for most shallow-rooted crops.

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Modeling Soil Water Movement in Pedostructure

10.13031/2013.20766 ◽

2006 ◽

Author(s):

Rabi H. Mohtar ◽

Erik Braudeau

Keyword(s):

Soil Water ◽

Water Movement ◽

Soil Water Movement

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Simulating soil-water movement under a hedgerow surrounding a bottomland reveals the importance of transpiration in water balance

Hydrological Processes ◽

10.1002/hyp.6619 ◽

2008 ◽

Vol 22 (5) ◽

pp. 577-585 ◽

Cited By ~ 14

Author(s):

Z. Thomas ◽

J. Molénat ◽

V. Caubel ◽

C. Grimaldi ◽

P. Mérot

Keyword(s):

Water Balance ◽

Soil Water ◽

Water Movement ◽

Soil Water Movement

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Discontinuous finite volume element method of two-dimensional unsaturated soil water movement problem

Advances in Difference Equations ◽

10.1186/s13662-019-2395-7 ◽

2019 ◽

Vol 2019 (1) ◽

Author(s):

Fan Chen ◽

Zhixiao Xu

Keyword(s):

Soil Water ◽

Finite Volume ◽

Unsaturated Soil ◽

Water Movement ◽

Optimal Error Estimate ◽

Two Dimensional ◽

Fully Discrete ◽

Volume Method ◽

Movement Problem ◽

Soil Water Movement

AbstractIn this paper, a numerical approximation method for the two-dimensional unsaturated soil water movement problem is established by using the discontinuous finite volume method. We prove the optimal error estimate for the fully discrete format. Finally, the reliability of the method is verified by numerical experiments. This method is not only simple to calculate, but also stable and reliable.

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