Modeling water infiltration in a large layered soil column with a modified Green–Ampt model and HYDRUS-1D

The installation of a traditional double-ring infiltrometer (DRI) into soil is difficult and time consuming. It results in reduced accuracy because of soil disturbance and water leakage along the gaps between the ring wall and the soil. In this study, a surface-positioned DRI (SPDRI) was suggested to improve measurement accuracy and convenience of the DRI. Laboratory experiments were conducted to evaluate performance of the method in terms of the influence of the lateral flow of water on the accuracy of infiltration rate, average vertical wetting front depth and saturated hydraulic conductivity. A cylindrical soil column was used to simulate the ideal ring infiltrometer (IRI) of the one-dimensional vertical infiltration process for comparison purposes. Experimental results indicated that the infiltration rates measured by the SPDRI and IRI were nearly identical, with maximum relative error (RE) of 18.75%. The vertical wetting front depth of the SPDRI was nearly identical to that of the IRI, with proportional coefficients of 0.97 and R2 > 0.95. Comparison of the soil saturated hydraulic conductivity with those from IRI indicated that the REs were 7.05–10.63% for the SPDRI. Experimental results demonstrated that the SPDRI could improve the measurement accuracy and facilitate the soil water infiltration measurement process.

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Numerical Study of Macropore Impact on Ponded Infiltration in Clay Soils

Soil and Water Research ◽

10.17221/6501-swr ◽

2013 ◽

Vol 1 (No. 1) ◽

pp. 16-22

Author(s):

Kodešova Radka ◽

Šimůnek Josef Kozak and Jiři

Keyword(s):

Numerical Simulations ◽

Preferential Flow ◽

Water Movement ◽

Numerical Study ◽

Water Infiltration ◽

Clay Soils ◽

Saturated Water ◽

Water Recharge ◽

Considerable Impact ◽

Hydrus 1D

The single-porosity and dual-permeability models in HYDRUS-1D (&Scaron;imůnek et al. 1998, 2003) were used to simulate variably-saturated water movement in clay soils with and without macropores. Numerical simulations of water flow for several scenarios of probable macropore compositions show a considerable impact of preferential flow on water infiltration in such soils. Preferential flow must be considered to predict water recharge in clay soils.

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Modeling infiltration responses of layered soil column under rainfall conditions

2011 International Conference on Electric Technology and Civil Engineering (ICETCE) ◽

10.1109/icetce.2011.5774246 ◽

2011 ◽

Author(s):

Dejun Yang ◽

Zhengfu Bian

Keyword(s):

Soil Column ◽

Layered Soil

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Study on Movement of Water and Salt through Soil Column and Utilization of Hydrus-1D Program to Simulate Five Scenarios of Crop Production in Salt Affected Paddy Soil

Modern Applied Science ◽

10.5539/mas.v10n1p139 ◽

2015 ◽

Vol 10 (1) ◽

pp. 139

Author(s):

Panom Chaiyasit ◽

Piya Duangpatra ◽

Visoot Verasan ◽

Varawoot Vudhivanich

Keyword(s):

Solute Transport ◽

Bulk Density ◽

Paddy Soil ◽

Mung Bean ◽

Soil Column ◽

Breakthrough Curves ◽

Pedotransfer Functions ◽

Hydraulic Parameters ◽

Transport Parameters ◽

Hydrus 1D

An experiment was conducted on the purpose to study movement of water and salt through soil column. Salt-affected paddy soil was assessed for its relevant transport parameters consisting of the hydraulic and the solute transport parameters. The hydraulic parameters included soil hydraulic conductivity (Ks) and the van Genuchten’s parameters (θs, θr, α, and n). In this experiment the solute transport parameters was referred to the coefficient of Langmuir’s isotherm which consisted of kd and η. Experience showed that hydraulic parameters were sensitive to changes of soil bulk density (ρb). Therefore pedotransfer functions describing the relations between these parameters with ρb were established. Straight line functions were found for θs and n, exponential functions were found for α and Ks, and logarithmic function was found for θr. Packing the soil in the physical column inevitably caused horizontal differentiation of different ρb. Bulk density of each layer was estimated by analysis of water flow through soil column at steady-state. Then ρb of each layer was calculated from the relation Ks (ρb). After the ρb was known the van Genuchten’s parameters were calculated from the pedotransfer functions. A physical column of 4 inches diameter and 50 cm length was constructed. Sodium chloride solution EC 6 dS/m was fed on soil surface during the process of salinization and the feeding solution was changed to fresh water during the process of desalinization. Breakthrough solution was analyzed for Na concentration and the breakthrough curves were constructed. The relevant parameters as well as initial and boundary conditions were fed into Hydrus-1D on the purpose to simulate the breakthrough curves. Statistical comparison results using t-test and RMSE suggested that Hydrus-1D could be used successfully to monitor transport of water and salt through soil column.Five scenarios concerning water and solute transport through soil profile under rice and mung bean cropping were simulated using Hydrus-1D. Simulation results suggested that continuous flooding was the most efficient way to leach soluble salts down to ground water. Wet/dry irrigation scheme for rice production could drain salts only when rice crop was in the first period of growth where crop water uptake was small. During later stages of growth concentration profile of Na remained almost unchange indicating negligible downward movement of salts. Leaving the soil to dry naturally during the dry season caused upward accumulation of salt to the degree smaller than cultivating mung bean since water content and hence the diffusion coefficient of the soil were higher and more favorable for upward salt diffusion than in the former case. Inserting the capillary rise hindering soil layer underneath mung bean root zone was found to retard upward diffusion of salt to the degree comparable to leaving the soil to dry naturally.

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Simulation Analysis of Vertical Movement of Nitrate Nitrogen in Vadose Zone of Fluvo-aquic Soil Based on HYDRUS-1D

E3S Web of Conferences ◽

10.1051/e3sconf/202129302008 ◽

2021 ◽

Vol 293 ◽

pp. 02008

Author(s):

Ping Jing ◽

Hui Zhang

Keyword(s):

Nitrate Nitrogen ◽

Simulation Analysis ◽

Model Simulation ◽

Pearson Correlation ◽

Soil Column ◽

Wastewater Reuse ◽

Stable State ◽

Ground Surface ◽

Linear Increase ◽

Hydrus 1D

Wastewater reuse has significant social, economic and ecological benefits, and has become an important measure to alleviate the water crisis. In this paper, in the simulation analysis of soil nitrate nitrogen, the method of combining soil column leaching and model simulation is used to test the accuracy of the model. The Pearson correlation coefficient is as high as 0.99 and the Nash coefficient is also over 0.9. It shows that the simulation results of the simulation model are credible. The Hydrus-1D model is used to visually simulate the change process of Tianjin fluvo-aquic soil over time. In the simulation, the process of solute migration in the 6-18 cm of the ground surface is basically the same, and they all reach a stable state about 4 hours, and show a linear increase trend four hours ago, and then the concentration remains stable and unchanged.

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Effects of grass type on hydraulic response of the three-layer landfill cover system

Waste Management & Research ◽

10.1177/0734242x211061213 ◽

2021 ◽

pp. 0734242X2110612

Author(s):

Song Feng ◽

Hong Wei Liu ◽

Qi Peng Cai ◽

Wen Bin Jian

Keyword(s):

Soil Column ◽

Infiltration Rate ◽

Root Water Uptake ◽

Water Infiltration ◽

Bermuda Grass ◽

Soil Layers ◽

Landfill Cover ◽

Water Percolation ◽

Landfill Cover System ◽

Soil Pores

Soil column tests were conducted to investigate the effects of grass type on water infiltration in a three-layer landfill cover under drying and wetting conditions. Five soil columns were prepared, including one bare, two Bermuda grass-planted and the other two vetiver-planted. During the drying period, the suction of vetiver-planted soil column was the largest, while that of bare case was the lowest. During the wetting period, the infiltration rate shows a bimodal form due to the contrasting hydraulic properties of different soil layers. The infiltration rate of vetiver-planted soil column was the lowest, followed by Bermuda grass-planted and bare cases. Correspondingly, the vetiver-planted soil column retained the maximum suction and the deepest ponding depth during rainfall. This was likely due to the larger leaf area and deeper roots of vetiver than those of Bermuda grass, thus inducing the maximum initial suction by root water uptake before rainfall and reducing the water permeability by root occupations of soil pores. These results show that vetiver is more effective than Bermuda grass to reduce water percolation through the three-layer landfill cover.

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