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Soil salinity increases when growers are forced to use higher salinity irrigation waters due to water shortages. It is necessary to estimate the impact of irrigation water on soil properties and conditions for crop growth to manage the effects of salinity on perennial crops. Therefore, in this study, we monitored root zone salinity in five almond and pistachio orchards in eastern and western San Joaquin Valley (SJV), California (CA). Volumetric soil water contents and bulk electrical conductivities were measured at four root-zone depths. Evapotranspiration was measured by eddy covariance along with three other types of data. The first is seasonal precipitation and irrigation patterns, including the temporal distribution of rains, irrigation events, and irrigation water salinity. The second is soil chemistry, including the initial sodium adsorption ratio (SAR) and soil solute electrical conductivity (ECe). The third type is the physical properties, including soil type, hydraulic conductivity, and bulk density. As expected, we found low salinity at the eastern sites and higher salinity at the western sites. The western sites have finer textured soils and lower quality irrigation water; measured actual ET was about 90% of modeled crop ET. Across the three western sites, the annual average apparent leaching fraction ranged from 11 to 28%. At the eastern sites, measured ET almost exactly matched modeled crop ET each year. Apparent leaching fractions in the eastern sites were approximately 20%.
Sarah A. Helalia; Ray G. Anderson; Todd H. Skaggs; G. Darrel Jenerette; Dong Wang; Jirka Šimůnek. Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 1. Observations. Soil Systems 2021, 5, 50 .
AMA StyleSarah A. Helalia, Ray G. Anderson, Todd H. Skaggs, G. Darrel Jenerette, Dong Wang, Jirka Šimůnek. Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 1. Observations. Soil Systems. 2021; 5 (3):50.
Chicago/Turabian StyleSarah A. Helalia; Ray G. Anderson; Todd H. Skaggs; G. Darrel Jenerette; Dong Wang; Jirka Šimůnek. 2021. "Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 1. Observations." Soil Systems 5, no. 3: 50.
Long-term use of recycled water (RW) for irrigation in arid and semiarid regions usually changes the soil solution composition and soil exchange characteristics, enhancing the risk for salinity and sodicity hazards in soils. This modelling study focuses on developing alternative management options that can reduce the potentially harmful impacts of RW use on the irrigation of wine grapes and almonds. The multicomponent UNSATCHEM add-on module for HYDRUS-1D was used to evaluate the impact of long-term (2018–2050) use of irrigation waters of different compositions: good-quality low-salinity (175 mg/L) water (GW), recycled water with 1200 mg/L salinity (RW), blended water of GW and RW in the 1:1 proportion (B), and monthly (Alt1) and half-yearly (Alt6) alternate use of GW and RW. The management options include different levels of annual gypsum applications (0, 1.7, 4.3, and 8.6 t/ha soil) to the calcareous (Cal) and hard red-brown (HRB) soils occurring in the Northern Adelaide Plain (NAP) region, South Australia. Additional management scenarios involve considering different leaching fractions (LF) (0.2, 0.3, 0.4, and 0.5) to reduce the salinity build-up in the soil. A new routine in UNSATCHEM to simulate annual gypsum applications was developed and tested for its applicability for ameliorating irrigation-induced soil sodicity. The 1970–2017 period with GW irrigation was used as a warmup period for the model. The water quality was switched from 2018 onwards to reflect different irrigation water qualities, gypsum applications, and LF levels. The data showed that the GW, B, Alt1, and Alt6 irrigation scenarios resulted in lower soil solution salinity (ECsw) than the RW irrigation scenario, which led to increased ECsw values (4.1–6.6 dS/m) in the soil. Annual gypsum applications of 1.7, 4.3, and 8.6 t/ha reduced pH, SAR, and ESP in both soils and reduced the adverse impacts of irrigation, especially in surface soils. A combination of water blending or cyclic water use with 3.8 t/ha annual gypsum applications showed promise for the SAR and ESP control. Additionally, irrigation with RW, a 0.2 LF, and annual gypsum applications limited the harmful salinity impacts in the soils. However, in the RW irrigation scenario, ECsw and ESP at the bottom of the crop root zone (90–120 cm depth) in the HRB soil were still higher than the wine grape and almond salinity thresholds. Thus, annual amendment applications, combined with the long-term use of blended water or cyclic use of RW and GW, represent a sustainable management option for crop production at the calcareous and hard red-brown soils.
Vinod Phogat; Dirk Mallants; Jirka Šimůnek; James W. Cox; Paul R. Petrie; Timothy Pitt. Modelling Salinity and Sodicity Risks of Long-Term Use of Recycled Water for Irrigation of Horticultural Crops. Soil Systems 2021, 5, 49 .
AMA StyleVinod Phogat, Dirk Mallants, Jirka Šimůnek, James W. Cox, Paul R. Petrie, Timothy Pitt. Modelling Salinity and Sodicity Risks of Long-Term Use of Recycled Water for Irrigation of Horticultural Crops. Soil Systems. 2021; 5 (3):49.
Chicago/Turabian StyleVinod Phogat; Dirk Mallants; Jirka Šimůnek; James W. Cox; Paul R. Petrie; Timothy Pitt. 2021. "Modelling Salinity and Sodicity Risks of Long-Term Use of Recycled Water for Irrigation of Horticultural Crops." Soil Systems 5, no. 3: 49.
Artificial capillary barriers (CBs) are used to improve root zone conditions as they can keep water and nutrients in the root zone by limiting downward percolation. Numerical analysis is one of the promising tools for evaluating CB systems’ performance during the cultivation of leafy vegetables. This study aims to investigate the effects of the CB system on soil water dynamics during spinach cultivation in a soil column under different irrigation scenarios using HYDRUS (2D/3D) by comparing uniform (UNI), line-source (LSI), and plant-targeted (PTI) irrigations combined with alternative irrigation schedules. Simulation results of volumetric soil water contents were generally corresponding to measured data. Simulation results with various hypothetical irrigation scenarios exhibited that the CB was an effective system to diminish percolation losses and improve the root zone’s soil water storage capacity. On the other hand, evaporation loss can be increased as more water is maintained near the surface. While this loss can be significantly minimized by reducing the water application area, the irrigation amount must be carefully defined because applying water in a smaller area may accelerate downward water movement so that the water content at the CB interface can reach close to saturation. In addition to the malfunction of the CB layer, it may also cause a reduction of plant root water uptake (RWU) because the root zone is too wet. Among evaluated irrigation scenarios, irrigating every two days with PTI was the best scenario for the spinach as water use efficiency was greatly improved.
Davy Sao; Hirotaka Saito; Tasuku Kato; Jirka Šimůnek. Numerical Analysis of Soil Water Dynamics during Spinach Cultivation in a Soil Column with an Artificial Capillary Barrier under Different Irrigation Managements. Water 2021, 13, 2176 .
AMA StyleDavy Sao, Hirotaka Saito, Tasuku Kato, Jirka Šimůnek. Numerical Analysis of Soil Water Dynamics during Spinach Cultivation in a Soil Column with an Artificial Capillary Barrier under Different Irrigation Managements. Water. 2021; 13 (16):2176.
Chicago/Turabian StyleDavy Sao; Hirotaka Saito; Tasuku Kato; Jirka Šimůnek. 2021. "Numerical Analysis of Soil Water Dynamics during Spinach Cultivation in a Soil Column with an Artificial Capillary Barrier under Different Irrigation Managements." Water 13, no. 16: 2176.
The use of plastic film mulching (PM) has steadily increased in the past few decades due to many advantages compared to no film mulching (NM). However, PM also has many drawbacks, such as producing plastic film residues and causing high temperatures at later crop growth stages. Thus, biodegradable film mulching (BM) has recently been used as an excellent alternative solution. In this study, the effects of three mulching types, including PM, BM, and NM, on soil temperatures (Ts) are evaluated using field experiments. Three mulching types with an irrigation depth of 22.5 mm (i.e., PM22.5, BM22.5, and NM22.5) and three irrigation depths of 15, 22.5, and 30 mm with BM (i.e., BM15, BM22.5, and BM30, respectively) were compared. Additionally, the Ts fluctuations and distributions during different crop growth stages were simulated using HYDRUS (2D/3D). The results showed that HYDRUS (2D/3D) successfully simulated Ts with RMSE of 2.11–4.00 °C, EF of 0.63−0.85, and MRE of 8.1 %–11.6 % during the validation period. There were large differences in Ts among PM22.5, BM22.5, and NM22.5 in different crop growth stages. In the elongation and tasseling stages, Ts under PM22.5 and BM22.5 was not significantly different but markedly improved compared with NM22.5. In the filling and maturation stages, higher variability of Ts was observed under BM22.5 compared with PM22.5. The standard deviation (SD), the deviation variance (DV), and the kurtosis coefficient (K) under BM22.5 were by 6.7 %, 32.6 %, and 19.3 % higher than under PM22.5, while accumulated soil temperature (AT) and the ratio of effective accumulated soil temperature (AET, ≥10 °C) to AT (RT) decreased by 3.8 % and 4.0 %, respectively. Additionally, apparent differences in Ts between BM22.5 and PM22.5 appeared mainly in the soil surface layer (0−10 cm). The area with “optimal Ts” (i.e., corn growth is optimal in the Ts range of 20−24 °C) in the 0−30 cm soil layer increased by 33.5 % under BM22.5 compared with PM22.5. Moreover, Ts decreased with an increase in the irrigation depth from BM15 to BM22.5, and BM30, with the maximum size of the “optimal Ts” area under BM22.5. Generally, BM has more advantages in terms of heat preservation and preventing high temperatures compared with NM and PM, respectively. Therefore, the biodegradable film can be recommended as an alternative material to replace the traditional polyethylene film.
Ning Chen; Xianyue Li; Jirí Šimůnek; Haibin Shi; Qi Hu; Yuehong Zhang. Evaluating the effects of biodegradable and plastic film mulching on soil temperature in a drip-irrigated field. Soil and Tillage Research 2021, 213, 105116 .
AMA StyleNing Chen, Xianyue Li, Jirí Šimůnek, Haibin Shi, Qi Hu, Yuehong Zhang. Evaluating the effects of biodegradable and plastic film mulching on soil temperature in a drip-irrigated field. Soil and Tillage Research. 2021; 213 ():105116.
Chicago/Turabian StyleNing Chen; Xianyue Li; Jirí Šimůnek; Haibin Shi; Qi Hu; Yuehong Zhang. 2021. "Evaluating the effects of biodegradable and plastic film mulching on soil temperature in a drip-irrigated field." Soil and Tillage Research 213, no. : 105116.
Optimization of nitrogen (N) fertigation is a formidable challenge involving complex interactions between water and N uptake and their effects on crop production. Numerical models can be useful in studying the interaction of multiple variables like those found in mechanistic simulations of N fertigation strategies. The physical aspects can often be accurately represented in soil-plant-atmosphere continuum models, while the biological factors lag due to their oversimplification. When optimizing N fertigation using numerical models, it is essential to consider the effects of N and water stresses on the plant size and corresponding feedback on potential transpiration and N uptake. The HYDRUS (2D/3D) model was modified to allow for active uptake and decay of multiple solutes and reduce potential transpiration due to a limitation in N uptake. Subsequently, we calibrated and validated the model with a dataset that consisted of 3 nitrate (NO3-) concentration and 6 irrigation levels: a total of 18 distinct treatments used to fertigate cucumber plants grown in lysimeters. The calibration was based on the treatment that received the highest N fertigation. The model was validated by testing its ability to accurately reduce potential N uptake and transpiration in water and N deficiency cases. Simulations showed that the N stress function could explain 82% of the reduction in transpiration measured in the experimental setup. The sensitivity analysis, evaluating the effects of the root shape and distribution parameters by increasing and decreasing their values by 20%, showed that these parameters had little impact on the results. Following its validation, the model was used to determine the optimal N concentration in irrigation water and the optimal N application amount to obtain maximal yield with minimal N loss. The optimal irrigation water NO3--N concentration and seasonal NO3--N application were determined to be 75 mg L−1 and 40 mg m−2, respectively.
Thomas Groenveld; Amir Argaman; Jiří Šimůnek; Naftali Lazarovitch. Numerical modeling to optimize nitrogen fertigation with consideration of transient drought and nitrogen stress. Agricultural Water Management 2021, 254, 106971 .
AMA StyleThomas Groenveld, Amir Argaman, Jiří Šimůnek, Naftali Lazarovitch. Numerical modeling to optimize nitrogen fertigation with consideration of transient drought and nitrogen stress. Agricultural Water Management. 2021; 254 ():106971.
Chicago/Turabian StyleThomas Groenveld; Amir Argaman; Jiří Šimůnek; Naftali Lazarovitch. 2021. "Numerical modeling to optimize nitrogen fertigation with consideration of transient drought and nitrogen stress." Agricultural Water Management 254, no. : 106971.
This study presents a conceptual Dual‐Permeability Non‐Equilibrium (DPNE) model that accounts for both physical and chemical non‐equilibria to describe the reactive solute transport through a porous medium. A semi‐analytical solution of the DPNE model is derived in the Laplace domain, which is then numerically inverted to obtain concentrations in different domains at different times and depths. The derived semi‐analytical solution is validated using experimental data and existing analytical (for simple problems) and numerical solutions. The Global Sensitivity Analysis (GSA) is performed to identify model parameters with an impact on nonreactive tracer breakthrough curves (BTC) for a selected data set. A sensitivity‐based calibration of the DPNE model’s parameters is carried out to simulate a BTC with multiple inflection points. The DPNE model can better describe the experimental datasets than the model based on the dual‐porosity (MIM) concept with first‐order mass transfer. Since the DPNE model considers detailed sorption and mass transfer dynamics, it is suitable for process‐based investigations.
Abhimanyu Sharma; Deepak Swami; Nitin Joshi; Aman Chandel; Jirka Šimůnek. The Semi‐Analytical Solution for Non‐Equilibrium Solute Transport in Dual‐Permeability Porous Media. Water Resources Research 2021, 57, 1 .
AMA StyleAbhimanyu Sharma, Deepak Swami, Nitin Joshi, Aman Chandel, Jirka Šimůnek. The Semi‐Analytical Solution for Non‐Equilibrium Solute Transport in Dual‐Permeability Porous Media. Water Resources Research. 2021; 57 (5):1.
Chicago/Turabian StyleAbhimanyu Sharma; Deepak Swami; Nitin Joshi; Aman Chandel; Jirka Šimůnek. 2021. "The Semi‐Analytical Solution for Non‐Equilibrium Solute Transport in Dual‐Permeability Porous Media." Water Resources Research 57, no. 5: 1.
Enhanced water use efficiency (WUE) is the key to sustainable agriculture in arid regions. The installation of capillary barriers (CB) has been suggested as one of the potential solutions. CB effects are observed between two soil layers with distinctly different soil hydraulic properties. A CB helps retain water in the upper, relatively fine-textured soil layer, suppressing water losses by deep drainage. However, retaining water in a shallow surface layer also intensifies water loss by evaporation. The use of subsurface drip irrigation (SDI) with a CB may prevent such water loss. This study evaluated the performance of SDI in a soil profile with a CB using a pot experiment and numerical analysis with the HYDRUS (2D/3D) software package. The ring-shaped emitter was selected for the SDI system for its low capital expenditures (CapEx) and maintenance. Strawberry was selected as a model plant. The results indicated that the proposed SDI system with a CB was effective in terms of WUE. The numerical analysis revealed that the CB’s depth influences the system’s water balance more than the ring-shaped emitter’s installation depth. While the CB’s shallow installation led to more root water uptake by the strawberry and less water loss by deep drainage, it induced more water loss by evaporation.
Koichi Noguchi; Hirotaka Saito; Reskiana Saefuddin; Jiří Šimůnek. Evaluation of Subsurface Drip Irrigation Designs in a Soil Profile with a Capillary Barrier. Water 2021, 13, 1300 .
AMA StyleKoichi Noguchi, Hirotaka Saito, Reskiana Saefuddin, Jiří Šimůnek. Evaluation of Subsurface Drip Irrigation Designs in a Soil Profile with a Capillary Barrier. Water. 2021; 13 (9):1300.
Chicago/Turabian StyleKoichi Noguchi; Hirotaka Saito; Reskiana Saefuddin; Jiří Šimůnek. 2021. "Evaluation of Subsurface Drip Irrigation Designs in a Soil Profile with a Capillary Barrier." Water 13, no. 9: 1300.
The classical Barenblatt solution of an initial-boundary value problem (IBVP) to the parabolic Boussinesq equation, which gives a rectangular triangle of full saturation, propagating from a reservoir into an adjacent porous bank with a vertical slope, is shown to coincide with a solution of IBVP to the elliptic Laplace equation with a phreatic surface along which both isobaricity and kinematic conditions are exactly met. For an arbitrary bank slope, a saturated wedge, which propagates (translates) into dry soil, is also explicitly found. The analytical solutions favorably compare with the results of HYDRUS-2D modeling, i.e., with the FEM solutions of the same IBVPs to the Richards equation. Applications to geotechnical engineering of dykes subject to the impact of flash floods are discussed by comparisons of phreatic lines, loci of the fronts, isobars, equipotential contours, vector fields of Darcian velocity, isotachs, and streamlines in the three models. For example, it is shown that a rapid drawup of the reservoir level induces hydraulic gradients, which may cause seepage-induced erosion of the porous medium, in particular, lessivage.
A.R. Kacimov; J. Šimůnek. Analytical traveling-wave solutions and HYDRUS modeling of wet wedges propagating into dry soils: Barenblatt's regime for Boussinesq's equation generalized. Journal of Hydrology 2021, 598, 126413 .
AMA StyleA.R. Kacimov, J. Šimůnek. Analytical traveling-wave solutions and HYDRUS modeling of wet wedges propagating into dry soils: Barenblatt's regime for Boussinesq's equation generalized. Journal of Hydrology. 2021; 598 ():126413.
Chicago/Turabian StyleA.R. Kacimov; J. Šimůnek. 2021. "Analytical traveling-wave solutions and HYDRUS modeling of wet wedges propagating into dry soils: Barenblatt's regime for Boussinesq's equation generalized." Journal of Hydrology 598, no. : 126413.
Seepage through an aquifer, the hydraulic conductivity of which varies vertically, is studied by using the Dupuit-Forchheimer approximation (Girinskii’s potential) and numerically by FDM-MODFLOW and FEM-HYDRUS-2D. In urban water hydrology, the effect of compaction of the top stratum of an aquifer on the flow rate and the position of the water table (characterized by an integral quantity of the saturated/dry area) is analyzed. The area of the saturated zone is evaluated as a function of the conductivity ratio of the two strata, and their thicknesses. Conductivity varying linearly and exponentially is also analytically studied. Boundary-value problems are solved for a linear (nonlinear) ordinary differential equation (ODE) if the evaporation rate is constant (decreasing exponentially with depth). The MODFLOW and HYDRUS-2D simulations give consistent fields of the piezometric head, pressure head, and Darcian velocity, as well as the water table position, which may have a global minimum (watershed).
A. R. Kacimov; A. Al-Maktoumi; J. Šimůnek. Water table rise in urban shallow aquifer with vertically-heterogeneous soils: Girinskii’s potential revisited. Hydrological Sciences Journal 2021, 66, 795 -808.
AMA StyleA. R. Kacimov, A. Al-Maktoumi, J. Šimůnek. Water table rise in urban shallow aquifer with vertically-heterogeneous soils: Girinskii’s potential revisited. Hydrological Sciences Journal. 2021; 66 (5):795-808.
Chicago/Turabian StyleA. R. Kacimov; A. Al-Maktoumi; J. Šimůnek. 2021. "Water table rise in urban shallow aquifer with vertically-heterogeneous soils: Girinskii’s potential revisited." Hydrological Sciences Journal 66, no. 5: 795-808.
Many arid and semi-arid regions of the world face challenges in maintaining the water quantity and quality needs of growing populations. A drywell is an engineered vadose zone infiltration device widely used for stormwater capture and managed aquifer recharge. To our knowledge, no prior studies have quantitatively examined virus transport from a drywell, especially in the presence of subsurface heterogeneity. Axisymmetric numerical experiments were conducted to systematically study virus fate from a drywell for various virus removal and subsurface heterogeneity scenarios under steady-state flow conditions from a constant head reservoir. Subsurface domains were homogeneous or had stochastic heterogeneity with selected standard deviation (σ) of lognormal distribution in saturated hydraulic conductivity and horizontal (X) and vertical (Z) correlation lengths. Low levels of virus concentration tailing can occur even at a separation distance of 22 m from the bottom of the drywell, and 6-log10 virus removal was not achieved when a small detachment rate (kd1=1 × 10⁻⁵ min⁻¹) is present in a homogeneous domain. Improved virus removal was achieved at a depth of 22 m in the presence of horizontal lenses (e.g., X=10 m, Z=0.1 m, σ=1) that enhanced the lateral movement and distribution of the virus. In contrast, faster downward movement of the virus with an early arrival time at a depth of 22 m occurred when considering a vertical correlation in permeability (X=1 m, Z=2 m, σ=1). Therefore, the general assumption of a 1.5-12 m separation distance to protect water quality may not be adequate in some instances, and site-specific microbial risk assessment is essential to minimize risk. Microbial water quality can potentially be improved by using an in situ soil treatment with iron oxides to increase irreversible attachment and solid-phase inactivation.
Salini Sasidharan; Scott A. Bradford; Jiří Šimůnek; Stephen R. Kraemer. Virus transport from drywells under constant head conditions: A modeling study. Water Research 2021, 197, 117040 .
AMA StyleSalini Sasidharan, Scott A. Bradford, Jiří Šimůnek, Stephen R. Kraemer. Virus transport from drywells under constant head conditions: A modeling study. Water Research. 2021; 197 ():117040.
Chicago/Turabian StyleSalini Sasidharan; Scott A. Bradford; Jiří Šimůnek; Stephen R. Kraemer. 2021. "Virus transport from drywells under constant head conditions: A modeling study." Water Research 197, no. : 117040.
Pakistan is facing severe water shortages, so using the available water efficiently is essential for maximizing crop production. This can be achieved through efficient irrigation practices. Field studies were carried out to determine the dynamics of soil water and the efficiency of water utilization for maize grown under five irrigation techniques (flood-irrigated flatbed, furrow-irrigated ridge, furrow-irrigated raised bed, furrow-irrigated raised bed with plastic mulch, and sprinkler-irrigated flatbed). Spring and summer maize was grown for two years. The Irrigation Management System (IManSys) was used to estimate the irrigation requirements, evapotranspiration, and other water balance components for this study’s different experimental treatments based on site-specific crop, soil, and weather parameters. The results showed that the flood irrigation flatbed (FIF) treatment produced the highest evapotranspiration, leaf area index (LAI), and biomass yield compared to other treatments. However, this treatment did not produce the highest grain yield and had the lowest water use efficiency (WUE) and irrigation water use efficiency (WUEi) compared to the furrow-irrigated raised-bed treatment. The furrow-irrigated raised bed with plastic mulch (FIRBM) treatment improved grain yield, WUE, WUEi , and harvest index compared to the flood irrigation flatbed (FIF) treatment. The results showed a strong correlation between measured and estimated net irrigation requirements and evapotranspiration, with high r 2 values (0.93, 0.99, 0.98, and 0.98) for the spring- and summer-sown maize. It was concluded that the FIRBM treatments improved the grain yield, WUE, and WUEi, which ultimately enhanced sustainable crop production. The growing of summer-sown maize in Pakistan has the potential for sustainable maize production under the semiarid and arid climate.
Abdul Khan; Muhammad Imran; Anwar-Ul-Hassan Khan; Ali Fares; Jiří Šimůnek; Tanveer Ul-Haq; Abdulaziz Alsahli; Mohammed Alyemeni; Shafaqat Ali. Performance of Spring and Summer-Sown Maize under Different Irrigation Strategies in Pakistan. Sustainability 2021, 13, 2757 .
AMA StyleAbdul Khan, Muhammad Imran, Anwar-Ul-Hassan Khan, Ali Fares, Jiří Šimůnek, Tanveer Ul-Haq, Abdulaziz Alsahli, Mohammed Alyemeni, Shafaqat Ali. Performance of Spring and Summer-Sown Maize under Different Irrigation Strategies in Pakistan. Sustainability. 2021; 13 (5):2757.
Chicago/Turabian StyleAbdul Khan; Muhammad Imran; Anwar-Ul-Hassan Khan; Ali Fares; Jiří Šimůnek; Tanveer Ul-Haq; Abdulaziz Alsahli; Mohammed Alyemeni; Shafaqat Ali. 2021. "Performance of Spring and Summer-Sown Maize under Different Irrigation Strategies in Pakistan." Sustainability 13, no. 5: 2757.
Numerical simulation of three-dimensional water flow and solute transport in containerized variably saturated soilless substrates with complex hydraulic properties and boundary conditions necessitates high-resolution discretization of the spatial and temporal domains, which commonly leads to several million nodes requiring numerical evaluation. Even today’s computing prowess of workstations is not adequate to tackle such problems within a reasonable timeframe, especially when numerous realizations are required to optimize the geometry, substrate properties, and irrigation and fertigation management of soilless plant growth modules. Hence, the parallelization of the numerical code and utilization of high performance computing (HPC) are essential. Here, we adapted and applied the ParSWMS parallelized code that is amenable to solving the 3D Richards equation for water flow and the convection-dispersion equation for solute transport subject to linear solute adsorption. The code was modified to allow for nonlinear equilibrium solute adsorption with new boundary conditions and applied to simulate water flow and nitrogen and phosphorus transport in containerized soilless substrates. Multi-solute transport simulations with the modified Linux ParSWMS code were first performed on a workstation and referenced to the Windows-based HYDRUS (2D/3D) numerical code. After confirming the agreement between the modified ParSWMS code and HYDRUS (2D/3D), various preconditioners and iterative solvers were evaluated to find the computationally most efficient combinations. The performance of the modified ParSWMS code and its stability were compared to HYDRUS (2D/3D) simulations for three soilless substrates consisting of horticultural perlite, volcanic tuff, and a volcanic tuff/coconut coir mixture. Considering the solute mass balance error as a stability measure, ParSWMS outperformed HYDRUS (2D/3D). Moreover, simulations with the modified ParSWMS code were about 22% faster than simulations with HYDRUS (2D/3D) on the workstation. Tests of the modified ParSWMS on two HPC clusters with 28 and 94 cores revealed a potential computational speedup of 94% relative to the HYDRUS (2D/3D) simulations performed on the workstation.
Mohammad R. Gohardoust; Jirka Šimůnek; Horst Hardelauf; Markus Tuller. Adaptation and validation of the ParSWMS numerical code for simulation of water flow and solute transport in soilless greenhouse substrates. Journal of Hydrology 2021, 596, 126053 .
AMA StyleMohammad R. Gohardoust, Jirka Šimůnek, Horst Hardelauf, Markus Tuller. Adaptation and validation of the ParSWMS numerical code for simulation of water flow and solute transport in soilless greenhouse substrates. Journal of Hydrology. 2021; 596 ():126053.
Chicago/Turabian StyleMohammad R. Gohardoust; Jirka Šimůnek; Horst Hardelauf; Markus Tuller. 2021. "Adaptation and validation of the ParSWMS numerical code for simulation of water flow and solute transport in soilless greenhouse substrates." Journal of Hydrology 596, no. : 126053.
The HYDRUS unsaturated flow and transport model was modified to simulate the effects of non-linear air-water interfacial (AWI) adsorption, solution surface tension-induced flow, and variable solution viscosity on the unsaturated transport of per- and polyfluoroalkyl substances (PFAS) within the vadose zone. These modifications were made and completed between March 2019 and May 2019, and were implemented into both the one-dimensional (1D) and two-dimensional (2D) versions of HYDRUS. Herein, the model modifications are described and validated against the available literature-derived PFAS transport data (i.e., 1D experimental column transport data). The results of both 1D and 2D example simulations are presented to highlight the function and utility of the model to capture the dynamic and transient nature of the temporally and spatially variable interfacial area of the AWI (Aaw) as it changes with soil moisture content (Θw) and how it affects PFAS unsaturated transport. Specifically, the simulated examples show that while AWI adsorption of PFAS can be a significant source of retention within the vadose zone, it is not always the dominant source of retention. The contribution of solid-phase sorption can be considerable in many PFAS-contaminated vadose zones. How the selection of an appropriate AawΘw function can impact PFAS transport and how both mechanisms contribute to PFAS mass flux to an underlying groundwater source is also demonstrated. Finally, the effects of soil textural heterogeneities on PFAS unsaturated transport are demonstrated in the results of both 1D and 2D example simulations.
Jeff Allen Kai Silva; Jiří Šimůnek; John E. McCray. A Modified HYDRUS Model for Simulating PFAS Transport in the Vadose Zone. Water 2020, 12, 2758 .
AMA StyleJeff Allen Kai Silva, Jiří Šimůnek, John E. McCray. A Modified HYDRUS Model for Simulating PFAS Transport in the Vadose Zone. Water. 2020; 12 (10):2758.
Chicago/Turabian StyleJeff Allen Kai Silva; Jiří Šimůnek; John E. McCray. 2020. "A Modified HYDRUS Model for Simulating PFAS Transport in the Vadose Zone." Water 12, no. 10: 2758.
An isobar generated by a line or point sink draining a confined semi-infinite aquifer is an analytic curve, to which a steady 2-D plane or axisymmetric Darcian flow converges. This sink may represent an excavation, ditch, or wadi on Earth, or a channel on Mars. The strength of the sink controls the form of the ditch depression: for 2-D flow, the shape of the isobar varies from a zero-depth channel to a semicircle; for axisymmetric flow, depressions as flat as a disk or as deep as a hemisphere are reconstructed. In the model of axisymmetric flow, a fictitious J.R. Philip's point sink is mirrored by an infinite array of sinks and sources placed along a vertical line perpendicular to a horizontal water table. A topographic depression is kept at constant capillary pressure (water content, Kirchhoff potential). None of these singularities belongs to the real flow domain, evaporating unsaturated Gardnerian soil. Saturated flow towards a triangular, empty or partially-filled ditch is tackled by conformal mappings and the solution of Riemann's problem in a reference plane. The obtained seepage flow rate is used as a right-hand side in an ODE of a Cauchy problem, the solution of which gives the draw-up curves, i.e., the rise of the water level in an initially empty trench. HYDRUS-2D computations for flows in saturated and unsaturated soils match well the analytical solutions. The modeling results are applied to assessments of real hydrological fluxes on Earth and paleo-reconstructions of Martian hydrology-geomorphology.
A.R. Kacimov; Yu.V. Obnosov; J. Šimůnek. Seepage to ditches and topographic depressions in saturated and unsaturated soils. Advances in Water Resources 2020, 145, 103732 .
AMA StyleA.R. Kacimov, Yu.V. Obnosov, J. Šimůnek. Seepage to ditches and topographic depressions in saturated and unsaturated soils. Advances in Water Resources. 2020; 145 ():103732.
Chicago/Turabian StyleA.R. Kacimov; Yu.V. Obnosov; J. Šimůnek. 2020. "Seepage to ditches and topographic depressions in saturated and unsaturated soils." Advances in Water Resources 145, no. : 103732.
Organic amendments are often reported to improve soil properties, promote plant growth, and improve crop yield. This study aimed to investigate the effects of the biochar and compost produced from sewage sludge and olive pomace on soil hydraulic properties, water flow, and P transport (i.e., sorption) using numerical modeling (HYDRUS-1D) applied to two soil types (Terra Rosa and Rendzina). Evaporation and leaching experiments on soil cores and repacked soil columns were performed to determine the soil water retention, hydraulic conductivity, P leaching potential, and P sorption capacity of these mixtures. In the majority of treatments, the soil water retention showed a small increase compared to the control soil. A reliable fit with the modified van Genuchten model was found, which was also confirmed by water flow modeling of leaching experiments (R2 0.99). The results showed a high P sorption in all the treatments (Kd 21.24 to 53.68 cm3 g–1), and a high model reliability when the inverse modeling procedure was used (R2 0.93 - 0.99). Overall, adding sewage sludge or olive pomace as compost or biochar improved the Terra Rosa and Rendzina water retention and did not increase the P mobility in these soils, proving to be a sustainable source of carbon and P-rich materials.
Vilim Filipović; Marko Černe; Jiří Šimůnek; Lana Filipović; Marija Romić; Gabrijel Ondrašek; Igor Bogunović; Ivan Mustać; Vedran Krevh; Anja Ferenčević; David Robinson; Igor Palčić; Igor Pasković; Smiljana Goreta Ban; Zoran Užila; Dean Ban. Modeling Water Flow and Phosphorus Sorption in a Soil Amended with Sewage Sludge and Olive Pomace as Compost or Biochar. Agronomy 2020, 10, 1163 .
AMA StyleVilim Filipović, Marko Černe, Jiří Šimůnek, Lana Filipović, Marija Romić, Gabrijel Ondrašek, Igor Bogunović, Ivan Mustać, Vedran Krevh, Anja Ferenčević, David Robinson, Igor Palčić, Igor Pasković, Smiljana Goreta Ban, Zoran Užila, Dean Ban. Modeling Water Flow and Phosphorus Sorption in a Soil Amended with Sewage Sludge and Olive Pomace as Compost or Biochar. Agronomy. 2020; 10 (8):1163.
Chicago/Turabian StyleVilim Filipović; Marko Černe; Jiří Šimůnek; Lana Filipović; Marija Romić; Gabrijel Ondrašek; Igor Bogunović; Ivan Mustać; Vedran Krevh; Anja Ferenčević; David Robinson; Igor Palčić; Igor Pasković; Smiljana Goreta Ban; Zoran Užila; Dean Ban. 2020. "Modeling Water Flow and Phosphorus Sorption in a Soil Amended with Sewage Sludge and Olive Pomace as Compost or Biochar." Agronomy 10, no. 8: 1163.
In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for soils and crops. In this study, an experiment was conducted on a tomato crop cultivated on a silty-clay soil irrigated with three different water qualities: 0, 3.5, and 7 dS·m−1. Experimental data were then used to calibrate and validate the Hydrus-1D model, which simulates water flow and salt transfer in soils. The successfully-calibrated and validated model was then used to study the combined effects of the soil osmotic and soil matrix potentials on root water uptake. The values of the root mean square error (RMSE), the coefficient of determination (CD), the modeling efficiency (EF), and the coefficient of residual mass (CRM) were close to their optimal values for both soil water content and soil electrical conductivity profiles, indicating the reliability of the model to reproduce water and salt dynamics. Relative yields (Yr), indirectly estimated using actual and potential root water uptake (transpiration), indicated that the multiplicative stress response model (using the S-shape model) satisfactorily simulates measured yields and reproduces the effects of irrigation with saline waters on crop yields. An alternative scenario using a reduction of water requirements by 50% was investigated to assess an irrigation method with considerable water savings. As the results show that relative yields, Yr, were only slightly reduced, the crop water requirements estimated by CROPWAT 8.0 must have been overestimated. The variation of the soil salinity in the root zone highlighted a high salinization risk in the short-term when water of 7 dS·m−1 is used for irrigation.
Sabri Kanzari; Issam Daghari; Jiří Šimůnek; Anis Younes; Riadh Ilahy; Sana Ben Mariem; Mourad Rezig; Béchir Ben Nouna; Hassouna Bahrouni; Mohamed Ali Ben Abdallah. Simulation of Water and Salt Dynamics in the Soil Profile in the Semi-Arid Region of Tunisia—Evaluation of the Irrigation Method for a Tomato Crop. Water 2020, 12, 1594 .
AMA StyleSabri Kanzari, Issam Daghari, Jiří Šimůnek, Anis Younes, Riadh Ilahy, Sana Ben Mariem, Mourad Rezig, Béchir Ben Nouna, Hassouna Bahrouni, Mohamed Ali Ben Abdallah. Simulation of Water and Salt Dynamics in the Soil Profile in the Semi-Arid Region of Tunisia—Evaluation of the Irrigation Method for a Tomato Crop. Water. 2020; 12 (6):1594.
Chicago/Turabian StyleSabri Kanzari; Issam Daghari; Jiří Šimůnek; Anis Younes; Riadh Ilahy; Sana Ben Mariem; Mourad Rezig; Béchir Ben Nouna; Hassouna Bahrouni; Mohamed Ali Ben Abdallah. 2020. "Simulation of Water and Salt Dynamics in the Soil Profile in the Semi-Arid Region of Tunisia—Evaluation of the Irrigation Method for a Tomato Crop." Water 12, no. 6: 1594.
Quantitative analyses of empirical data requirements for hydrological simulations are rare. This study aims to analyze how a multi-objective optimization framework and information content computations aid in quantifying field-scale data worth in drainage studies. The results showed how a 1D numerical model and a differential evolution algorithm performed in describing the field water balance. The choice of the optimization target (subsurface drain discharge and surface runoff) impacted the simulation results more than parameter deviations. While the information content of surface runoff data was higher than that of drain discharge, drain discharge data contained more information on most of the soil parameters. Uncertainties related to groundwater outflow data, which were not used in the optimization, were higher than those of drain discharge and surface runoff. A central weighing optimization scheme with two data types produced the best but still incomplete description of the field hydrology. Despite the modest model performance, the results demonstrated how the choice of empirical data and optimization strategy can lead to uncertainties in drainage simulations and how the uncertainties can be assessed. Practically, a low amount of information and a parameter sensitivity analysis can lead to a biased description of uncertainty related to such hydrological variables which are not used in the optimization. Benefits of the modeling framework were shown when assessing (1) model structure adequacy with the Pareto front analysis, (2) information content of different data types regarding different parameters, and (3) uncertainties related to simulating hydrological variables based on optimization against a given data type.
M. Turunen; G. Gurarslan; J. Šimůnek; H. Koivusalo. What is the worth of drain discharge and surface runoff data in hydrological simulations? Journal of Hydrology 2020, 587, 125030 .
AMA StyleM. Turunen, G. Gurarslan, J. Šimůnek, H. Koivusalo. What is the worth of drain discharge and surface runoff data in hydrological simulations? Journal of Hydrology. 2020; 587 ():125030.
Chicago/Turabian StyleM. Turunen; G. Gurarslan; J. Šimůnek; H. Koivusalo. 2020. "What is the worth of drain discharge and surface runoff data in hydrological simulations?" Journal of Hydrology 587, no. : 125030.
Freeze-thaw cycles play a critical role in affecting ecosystem services in arid regions. Monitoring studies of soil temperature and moisture during a freeze-thaw process can generate data for research on the coupled movement of water, vapor, and heat during the freezing-thawing period which can, in turn, provide theoretical guidance for rational irrigation practices and ecological protection. In this study, the soil temperature and moisture changes in the deep vadose zone were observed by in-situ monitoring from November 2017 to March 2018 in the Mu Us Desert. The results showed that changes in soil temperatures and temperature gradients were largest in soil layers above the 100-cm depth, and variations decreased with soil depth. The relationship between soil temperature and unfrozen water content can be depicted well by both theoretical and empirical models. Due to gradients of the matric potential and temperature, soil water flowed from deeper soil layers towards the frozen soil, increasing the total water content at the freezing front. The vapor flux, which was affected mainly by temperature, showed diurnal variations in the shallow 20-cm soil layer, and its rate and variations decreased gradually with increasing soil depths. The freeze-thaw process can be divided into three stages: the initial freezing stage, the downward freezing stage, and the thawing stage. The upward vapor flux contributed to the formation of the frozen layer during the freezing process.
Ce Zheng; Yudong Lu; Xiuhua Liu; Jiří Šimůnek; Yijian Zeng; Changchun Shi; Huanhuan Li. In-Situ Monitoring and Characteristic Analysis of Freezing-Thawing Cycles in a Deep Vadose Zone. Water 2020, 12, 1261 .
AMA StyleCe Zheng, Yudong Lu, Xiuhua Liu, Jiří Šimůnek, Yijian Zeng, Changchun Shi, Huanhuan Li. In-Situ Monitoring and Characteristic Analysis of Freezing-Thawing Cycles in a Deep Vadose Zone. Water. 2020; 12 (5):1261.
Chicago/Turabian StyleCe Zheng; Yudong Lu; Xiuhua Liu; Jiří Šimůnek; Yijian Zeng; Changchun Shi; Huanhuan Li. 2020. "In-Situ Monitoring and Characteristic Analysis of Freezing-Thawing Cycles in a Deep Vadose Zone." Water 12, no. 5: 1261.
Simulation models that describe the flow and transport processes of pesticides in soil and groundwater are important tools to analyze how surface pesticide applications influence groundwater quality. The aim of this study is to investigate whether the slow decline and the stable spatial pattern of atrazine concentrations after its ban, which were observed in a long-term monitoring study of pesticide concentrations in the Zwischenscholle aquifer (Germany), could be explained by such model simulations. Model simulations were carried out using MODFLOW model coupled with the HYDRUS-1D package and MT3DMS. The results indicate that the spatial variability in the atrazine application rate and the volume of water entering and leaving the aquifer through lateral boundaries produced variations in the spatial distribution of atrazine in the aquifer. The simulated and observed water table levels and the average annual atrazine concentrations were found to be comparable. The long-term analysis of the simulated impact of atrazine applications in the study area shows that atrazine persisted in groundwater even 20 years after its ban at an average atrazine concentration of 0.035 µg/L. These results corroborate the findings of the previous monitoring studies.
Sahila Beegum; Jan VanderBorght; Jiří Šimůnek; Michael Herbst; K. P. Sudheer; Indumathi M Nambi. Investigating Atrazine Concentrations in the Zwischenscholle Aquifer Using MODFLOW with the HYDRUS-1D Package and MT3DMS. Water 2020, 12, 1019 .
AMA StyleSahila Beegum, Jan VanderBorght, Jiří Šimůnek, Michael Herbst, K. P. Sudheer, Indumathi M Nambi. Investigating Atrazine Concentrations in the Zwischenscholle Aquifer Using MODFLOW with the HYDRUS-1D Package and MT3DMS. Water. 2020; 12 (4):1019.
Chicago/Turabian StyleSahila Beegum; Jan VanderBorght; Jiří Šimůnek; Michael Herbst; K. P. Sudheer; Indumathi M Nambi. 2020. "Investigating Atrazine Concentrations in the Zwischenscholle Aquifer Using MODFLOW with the HYDRUS-1D Package and MT3DMS." Water 12, no. 4: 1019.
New water-conserving irrigation technologies are vital in arid countries. We investigated the effects of (i) soil substrates made of Smart Capillary Barrier Wick (SCB-W), consisting of silt loam blocks surrounded by sand-sheathes and irrigated with a sand wick cylinder (WC) as compared to a control (homogenous soil irrigated by the same wick system, HW), (ii) WC diameters (2.54 cm vs. 1.27 cm), and (iii) 2-cm sand mulch layer on soil–water dynamics during wetting–drying cycles. Field experiments with pots and HYDRUS (2D/3D) modeling were performed in two consecutive phases (with and without sand mulch). Analysis of variance at p < 0.05 was used to assess significant differences in measured water contents, θ, between the two substrates. For the wetting/drying cycles, the modeled and measured θ are in satisfactory/tolerable agreement, as documented by the model evaluation criteria, which are within acceptable ranges (the root mean squared error, RMSE 0.01–0.06; Nash–Sutcliffe coefficient, NSE 0.51–0.97, and Willmott index, d = 0.97–1). SCB-W wets the soil substrate about two times faster than HW during the wetting cycles (p < 0.05). Reducing the WC diameter prolonged the wetting time by 1 and 2 days for SCB-W and HW, respectively, the same trend of two times faster wetting of SCB-W compared to HW was maintained. SCB-W showed higher θ storage (by 44.3–52.4%) at the bottom part of the composite than HW (p < 0.05). The sand mulch layer reduced evaporation and resulted in 20 and 38.9% higher θ during the drying cycle for both the bottom and top sensors, respectively, in both substrates (p < 0.05). SCB-W could improve water conservation in home gardens.
A. Al-Mayahi; S. Al-Ismaily; A. Al-Maktoumi; H. Al-Busaidi; A. Kacimov; R. Janke; J. Bouma; J. Šimůnek. A smart capillary barrier-wick irrigation system for home gardens in arid zones. Irrigation Science 2020, 38, 235 -250.
AMA StyleA. Al-Mayahi, S. Al-Ismaily, A. Al-Maktoumi, H. Al-Busaidi, A. Kacimov, R. Janke, J. Bouma, J. Šimůnek. A smart capillary barrier-wick irrigation system for home gardens in arid zones. Irrigation Science. 2020; 38 (3):235-250.
Chicago/Turabian StyleA. Al-Mayahi; S. Al-Ismaily; A. Al-Maktoumi; H. Al-Busaidi; A. Kacimov; R. Janke; J. Bouma; J. Šimůnek. 2020. "A smart capillary barrier-wick irrigation system for home gardens in arid zones." Irrigation Science 38, no. 3: 235-250.