TY - JOUR
T1 - Water flow and multicomponent solute transport in drip-irrigated lysimeters
AU - Raij, Iael
AU - Šimůnek, Jiří
AU - Ben-Gal, Alon
AU - Lazarovitch, Naftali
N1 - Publisher Copyright:
© 2016. American Geophysical Union. All Rights Reserved.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Controlled experiments and modeling are crucial components in the evaluation of the fate of water and solutes in environmental and agricultural research. Lysimeters are commonly used to determine water and solute balances and assist in making sustainable decisions with respect to soil reclamation, fertilization, or irrigation with low-quality water. While models are cost-effective tools for estimating and preventing environmental damage by agricultural activities, their value is highly dependent on the accuracy of their parameterization, often determined by calibration. The main objective of this study was to use measured major ion concentrations collected from drip-irrigated lysimeters to calibrate the variably saturated water flow model HYDRUS (2D/3D) coupled with the reactive transport model UNSATCHEM. Irrigation alternated between desalinated and brackish waters. Lysimeter drainage and soil solution samples were collected for chemical analysis and used to calibrate the model. A second objective was to demonstrate the potential use of the calibrated model to evaluate lower boundary design options of lysimeters with respect to leaching fractions determined using drainage water fluxes, chloride concentrations, and overall salinity of drainage water, and exchangeable sodium percentage (ESP) in the profile. The model showed that, in the long term, leaching fractions calculated with electrical conductivity values would be affected by the lower boundary condition pressure head, while those calculated with chloride concentrations and water fluxes would not be affected. In addition, clear dissimilarities in ESP profiles were found between lysimeters with different lower boundary conditions, suggesting a potential influence on hydraulic conductivities and flow patterns.
AB - Controlled experiments and modeling are crucial components in the evaluation of the fate of water and solutes in environmental and agricultural research. Lysimeters are commonly used to determine water and solute balances and assist in making sustainable decisions with respect to soil reclamation, fertilization, or irrigation with low-quality water. While models are cost-effective tools for estimating and preventing environmental damage by agricultural activities, their value is highly dependent on the accuracy of their parameterization, often determined by calibration. The main objective of this study was to use measured major ion concentrations collected from drip-irrigated lysimeters to calibrate the variably saturated water flow model HYDRUS (2D/3D) coupled with the reactive transport model UNSATCHEM. Irrigation alternated between desalinated and brackish waters. Lysimeter drainage and soil solution samples were collected for chemical analysis and used to calibrate the model. A second objective was to demonstrate the potential use of the calibrated model to evaluate lower boundary design options of lysimeters with respect to leaching fractions determined using drainage water fluxes, chloride concentrations, and overall salinity of drainage water, and exchangeable sodium percentage (ESP) in the profile. The model showed that, in the long term, leaching fractions calculated with electrical conductivity values would be affected by the lower boundary condition pressure head, while those calculated with chloride concentrations and water fluxes would not be affected. In addition, clear dissimilarities in ESP profiles were found between lysimeters with different lower boundary conditions, suggesting a potential influence on hydraulic conductivities and flow patterns.
KW - drip irrigation
KW - leaching fraction
KW - lysimeters
KW - parameterization
KW - transport modeling
UR - http://www.scopus.com/inward/record.url?scp=84983543795&partnerID=8YFLogxK
U2 - 10.1002/2016WR018930
DO - 10.1002/2016WR018930
M3 - Article
AN - SCOPUS:84983543795
SN - 0043-1397
VL - 52
SP - 6557
EP - 6574
JO - Water Resources Research
JF - Water Resources Research
IS - 8
ER -